Commit Graph

545 Commits

Author SHA1 Message Date
Tang Chen
fe71557afb kvm: Add arch specific mmu notifier for page invalidation
This will be used to let the guest run while the APIC access page is
not pinned.  Because subsequent patches will fill in the function
for x86, place the (still empty) x86 implementation in the x86.c file
instead of adding an inline function in kvm_host.h.

Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-24 14:07:59 +02:00
Tang Chen
445b823695 kvm: Rename make_all_cpus_request() to kvm_make_all_cpus_request() and make it non-static
Different architectures need different requests, and in fact we
will use this function in architecture-specific code later. This
will be outside kvm_main.c, so make it non-static and rename it to
kvm_make_all_cpus_request().

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-24 14:07:59 +02:00
Andres Lagar-Cavilla
5712846808 kvm: Fix page ageing bugs
1. We were calling clear_flush_young_notify in unmap_one, but we are
within an mmu notifier invalidate range scope. The spte exists no more
(due to range_start) and the accessed bit info has already been
propagated (due to kvm_pfn_set_accessed). Simply call
clear_flush_young.

2. We clear_flush_young on a primary MMU PMD, but this may be mapped
as a collection of PTEs by the secondary MMU (e.g. during log-dirty).
This required expanding the interface of the clear_flush_young mmu
notifier, so a lot of code has been trivially touched.

3. In the absence of shadow_accessed_mask (e.g. EPT A bit), we emulate
the access bit by blowing the spte. This requires proper synchronizing
with MMU notifier consumers, like every other removal of spte's does.

Signed-off-by: Andres Lagar-Cavilla <andreslc@google.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-24 14:07:58 +02:00
David Matlack
2ea75be321 kvm: don't take vcpu mutex for obviously invalid vcpu ioctls
vcpu ioctls can hang the calling thread if issued while a vcpu is running.
However, invalid ioctls can happen when userspace tries to probe the kind
of file descriptors (e.g. isatty() calls ioctl(TCGETS)); in that case,
we know the ioctl is going to be rejected as invalid anyway and we can
fail before trying to take the vcpu mutex.

This patch does not change functionality, it just makes invalid ioctls
fail faster.

Cc: stable@vger.kernel.org
Signed-off-by: David Matlack <dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-24 14:07:55 +02:00
Andres Lagar-Cavilla
234b239bea kvm: Faults which trigger IO release the mmap_sem
When KVM handles a tdp fault it uses FOLL_NOWAIT. If the guest memory
has been swapped out or is behind a filemap, this will trigger async
readahead and return immediately. The rationale is that KVM will kick
back the guest with an "async page fault" and allow for some other
guest process to take over.

If async PFs are enabled the fault is retried asap from an async
workqueue. If not, it's retried immediately in the same code path. In
either case the retry will not relinquish the mmap semaphore and will
block on the IO. This is a bad thing, as other mmap semaphore users
now stall as a function of swap or filemap latency.

This patch ensures both the regular and async PF path re-enter the
fault allowing for the mmap semaphore to be relinquished in the case
of IO wait.

Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Andres Lagar-Cavilla <andreslc@google.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-24 14:07:54 +02:00
Paolo Bonzini
3c3c29fd0d kvm-vfio: do not use module_init
/me got confused between the kernel and QEMU.  In the kernel, you can
only have one module_init function, and it will prevent unloading the
module unless you also have the corresponding module_exit function.

So, commit 80ce163972 (KVM: VFIO: register kvm_device_ops dynamically,
2014-09-02) broke unloading of the kvm module, by adding a module_init
function and no module_exit.

Repair it by making kvm_vfio_ops_init weak, and checking it in
kvm_init.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Alex Williamson <Alex.Williamson@redhat.com>
Fixes: 80ce163972
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-24 14:06:36 +02:00
Sam Bobroff
27fbe64bfa KVM: correct null pid check in kvm_vcpu_yield_to()
Correct a simple mistake of checking the wrong variable
before a dereference, resulting in the dereference not being
properly protected by rcu_dereference().

Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-22 13:21:29 +02:00
Christoffer Dall
a875dafcf9 Merge remote-tracking branch 'kvm/next' into queue
Conflicts:
	arch/arm64/include/asm/kvm_host.h
	virt/kvm/arm/vgic.c
2014-09-18 18:15:32 -07:00
Will Deacon
80ce163972 KVM: VFIO: register kvm_device_ops dynamically
Now that we have a dynamic means to register kvm_device_ops, use that
for the VFIO kvm device, instead of relying on the static table.

This is achieved by a module_init call to register the ops with KVM.

Cc: Gleb Natapov <gleb@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Alex Williamson <Alex.Williamson@redhat.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-17 13:10:10 +02:00
Cornelia Huck
84877d9333 KVM: s390: register flic ops dynamically
Using the new kvm_register_device_ops() interface makes us get rid of
an #ifdef in common code.

Cc: Gleb Natapov <gleb@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-17 13:10:09 +02:00
Will Deacon
c06a841bf3 KVM: ARM: vgic: register kvm_device_ops dynamically
Now that we have a dynamic means to register kvm_device_ops, use that
for the ARM VGIC, instead of relying on the static table.

Cc: Gleb Natapov <gleb@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-17 13:10:09 +02:00
Will Deacon
d60eacb070 KVM: device: add simple registration mechanism for kvm_device_ops
kvm_ioctl_create_device currently has knowledge of all the device types
and their associated ops. This is fairly inflexible when adding support
for new in-kernel device emulations, so move what we currently have out
into a table, which can support dynamic registration of ops by new
drivers for virtual hardware.

Cc: Alex Williamson <Alex.Williamson@redhat.com>
Cc: Alex Graf <agraf@suse.de>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-17 13:10:08 +02:00
Ard Biesheuvel
85c8555ff0 KVM: check for !is_zero_pfn() in kvm_is_mmio_pfn()
Read-only memory ranges may be backed by the zero page, so avoid
misidentifying it a a MMIO pfn.

This fixes another issue I identified when testing QEMU+KVM_UEFI, where
a read to an uninitialized emulated NOR flash brought in the zero page,
but mapped as a read-write device region, because kvm_is_mmio_pfn()
misidentifies it as a MMIO pfn due to its PG_reserved bit being set.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Fixes: b88657674d ("ARM: KVM: user_mem_abort: support stage 2 MMIO page mapping")
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-14 16:26:05 +02:00
Christian Borntraeger
f2a2516088 KVM: remove redundant assignments in __kvm_set_memory_region
__kvm_set_memory_region sets r to EINVAL very early.
Doing it again is not necessary. The same is true later on, where
r is assigned -ENOMEM twice.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-05 12:01:15 +02:00
Christian Borntraeger
a13f533b2f KVM: remove redundant assigment of return value in kvm_dev_ioctl
The first statement of kvm_dev_ioctl is
        long r = -EINVAL;

No need to reassign the same value.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-05 12:01:15 +02:00
Christian Borntraeger
3465611318 KVM: remove redundant check of in_spin_loop
The expression `vcpu->spin_loop.in_spin_loop' is always true,
because it is evaluated only when the condition
`!vcpu->spin_loop.in_spin_loop' is false.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-05 12:01:14 +02:00
David Matlack
ee3d1570b5 kvm: fix potentially corrupt mmio cache
vcpu exits and memslot mutations can run concurrently as long as the
vcpu does not aquire the slots mutex. Thus it is theoretically possible
for memslots to change underneath a vcpu that is handling an exit.

If we increment the memslot generation number again after
synchronize_srcu_expedited(), vcpus can safely cache memslot generation
without maintaining a single rcu_dereference through an entire vm exit.
And much of the x86/kvm code does not maintain a single rcu_dereference
of the current memslots during each exit.

We can prevent the following case:

   vcpu (CPU 0)                             | thread (CPU 1)
--------------------------------------------+--------------------------
1  vm exit                                  |
2  srcu_read_unlock(&kvm->srcu)             |
3  decide to cache something based on       |
     old memslots                           |
4                                           | change memslots
                                            | (increments generation)
5                                           | synchronize_srcu(&kvm->srcu);
6  retrieve generation # from new memslots  |
7  tag cache with new memslot generation    |
8  srcu_read_unlock(&kvm->srcu)             |
...                                         |
   <action based on cache occurs even       |
    though the caching decision was based   |
    on the old memslots>                    |
...                                         |
   <action *continues* to occur until next  |
    memslot generation change, which may    |
    be never>                               |
                                            |

By incrementing the generation after synchronizing with kvm->srcu readers,
we ensure that the generation retrieved in (6) will become invalid soon
after (8).

Keeping the existing increment is not strictly necessary, but we
do keep it and just move it for consistency from update_memslots to
install_new_memslots.  It invalidates old cached MMIOs immediately,
instead of having to wait for the end of synchronize_srcu_expedited,
which makes the code more clearly correct in case CPU 1 is preempted
right after synchronize_srcu() returns.

To avoid halving the generation space in SPTEs, always presume that the
low bit of the generation is zero when reconstructing a generation number
out of an SPTE.  This effectively disables MMIO caching in SPTEs during
the call to synchronize_srcu_expedited.  Using the low bit this way is
somewhat like a seqcount---where the protected thing is a cache, and
instead of retrying we can simply punt if we observe the low bit to be 1.

Cc: stable@vger.kernel.org
Signed-off-by: David Matlack <dmatlack@google.com>
Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Reviewed-by: David Matlack <dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-03 10:03:41 +02:00
Paolo Bonzini
00f034a12f KVM: do not bias the generation number in kvm_current_mmio_generation
The next patch will give a meaning (a la seqcount) to the low bit of the
generation number.  Ensure that it matches between kvm->memslots->generation
and kvm_current_mmio_generation().

Cc: stable@vger.kernel.org
Reviewed-by: David Matlack <dmatlack@google.com>
Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-03 10:03:35 +02:00
Radim Krčmář
13a34e067e KVM: remove garbage arg to *hardware_{en,dis}able
In the beggining was on_each_cpu(), which required an unused argument to
kvm_arch_ops.hardware_{en,dis}able, but this was soon forgotten.

Remove unnecessary arguments that stem from this.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-29 16:35:55 +02:00
Christoffer Dall
0f8a4de3e0 KVM: Unconditionally export KVM_CAP_READONLY_MEM
The idea between capabilities and the KVM_CHECK_EXTENSION ioctl is that
userspace can, at run-time, determine if a feature is supported or not.
This allows KVM to being supporting a new feature with a new kernel
version without any need to update user space.  Unfortunately, since the
definition of KVM_CAP_READONLY_MEM was guarded by #ifdef
__KVM_HAVE_READONLY_MEM, such discovery still required a user space
update.

Therefore, unconditionally export KVM_CAP_READONLY_MEM and change the
in-kernel conditional to rely on __KVM_HAVE_READONLY_MEM.

Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-29 13:47:04 +02:00
Christoffer Dall
64d831269c KVM: Introduce gfn_to_hva_memslot_prot
To support read-only memory regions on arm and arm64, we have a need to
resolve a gfn to an hva given a pointer to a memslot to avoid looping
through the memslots twice and to reuse the hva error checking of
gfn_to_hva_prot(), add a new gfn_to_hva_memslot_prot() function and
refactor gfn_to_hva_prot() to use this function.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-08-27 22:46:08 +02:00
Radim Krčmář
e790d9ef64 KVM: add kvm_arch_sched_in
Introduce preempt notifiers for architecture specific code.
Advantage over creating a new notifier in every arch is slightly simpler
code and guaranteed call order with respect to kvm_sched_in.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-21 18:45:21 +02:00
Christian Borntraeger
7103f60de8 KVM: avoid unnecessary synchronize_rcu
We dont have to wait for a grace period if there is no oldpid that
we are going to free. putpid also checks for NULL, so this patch
only fences synchronize_rcu.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-21 13:50:22 +02:00
Paolo Bonzini
c77dcacb39 KVM: Move more code under CONFIG_HAVE_KVM_IRQFD
Commits e4d57e1ee1 (KVM: Move irq notifier implementation into
eventfd.c, 2014-06-30) included the irq notifier code unconditionally
in eventfd.c, while it was under CONFIG_HAVE_KVM_IRQCHIP before.

Similarly, commit 297e21053a (KVM: Give IRQFD its own separate enabling
Kconfig option, 2014-06-30) moved code from CONFIG_HAVE_IRQ_ROUTING
to CONFIG_HAVE_KVM_IRQFD but forgot to move the pieces that used to be
under CONFIG_HAVE_KVM_IRQCHIP.

Together, this broke compilation without CONFIG_KVM_XICS.  Fix by adding
or changing the #ifdefs so that they point at CONFIG_HAVE_KVM_IRQFD.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-06 14:24:47 +02:00
Paul Mackerras
297e21053a KVM: Give IRQFD its own separate enabling Kconfig option
Currently, the IRQFD code is conditional on CONFIG_HAVE_KVM_IRQ_ROUTING.
So that we can have the IRQFD code compiled in without having the
IRQ routing code, this creates a new CONFIG_HAVE_KVM_IRQFD, makes
the IRQFD code conditional on it instead of CONFIG_HAVE_KVM_IRQ_ROUTING,
and makes all the platforms that currently select HAVE_KVM_IRQ_ROUTING
also select HAVE_KVM_IRQFD.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Tested-by: Eric Auger <eric.auger@linaro.org>
Tested-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-05 14:26:28 +02:00
Alexander Graf
92b591a4c4 KVM: Allow KVM_CHECK_EXTENSION on the vm fd
The KVM_CHECK_EXTENSION is only available on the kvm fd today. Unfortunately
on PPC some of the capabilities change depending on the way a VM was created.

So instead we need a way to expose capabilities as VM ioctl, so that we can
see which VM type we're using (HV or PR). To enable this, add the
KVM_CHECK_EXTENSION ioctl to our vm ioctl portfolio.

Signed-off-by: Alexander Graf <agraf@suse.de>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
2014-07-28 15:23:17 +02:00
Alexander Graf
784aa3d7fb KVM: Rename and add argument to check_extension
In preparation to make the check_extension function available to VM scope
we add a struct kvm * argument to the function header and rename the function
accordingly. It will still be called from the /dev/kvm fd, but with a NULL
argument for struct kvm *.

Signed-off-by: Alexander Graf <agraf@suse.de>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
2014-07-28 15:23:17 +02:00
Linus Torvalds
b2e09f633a Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull more scheduler updates from Ingo Molnar:
 "Second round of scheduler changes:
   - try-to-wakeup and IPI reduction speedups, from Andy Lutomirski
   - continued power scheduling cleanups and refactorings, from Nicolas
     Pitre
   - misc fixes and enhancements"

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/deadline: Delete extraneous extern for to_ratio()
  sched/idle: Optimize try-to-wake-up IPI
  sched/idle: Simplify wake_up_idle_cpu()
  sched/idle: Clear polling before descheduling the idle thread
  sched, trace: Add a tracepoint for IPI-less remote wakeups
  cpuidle: Set polling in poll_idle
  sched: Remove redundant assignment to "rt_rq" in update_curr_rt(...)
  sched: Rename capacity related flags
  sched: Final power vs. capacity cleanups
  sched: Remove remaining dubious usage of "power"
  sched: Let 'struct sched_group_power' care about CPU capacity
  sched/fair: Disambiguate existing/remaining "capacity" usage
  sched/fair: Change "has_capacity" to "has_free_capacity"
  sched/fair: Remove "power" from 'struct numa_stats'
  sched: Fix signedness bug in yield_to()
  sched/fair: Use time_after() in record_wakee()
  sched/balancing: Reduce the rate of needless idle load balancing
  sched/fair: Fix unlocked reads of some cfs_b->quota/period
2014-06-12 19:42:15 -07:00
Dan Carpenter
fa93384f40 sched: Fix signedness bug in yield_to()
yield_to() is supposed to return -ESRCH if there is no task to
yield to, but because the type is bool that is the same as returning
true.

The only place I see which cares is kvm_vcpu_on_spin().

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Raghavendra <raghavendra.kt@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org
Link: http://lkml.kernel.org/r/20140523102042.GA7267@mwanda
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-06-05 11:52:13 +02:00
Paolo Bonzini
820b3fcdeb KVM: add missing cleanup_srcu_struct
Reported-by: hrg <hrgstephen@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-06-03 13:44:17 +02:00
Christian Borntraeger
719d93cd5f kvm/irqchip: Speed up KVM_SET_GSI_ROUTING
When starting lots of dataplane devices the bootup takes very long on
Christian's s390 with irqfd patches. With larger setups he is even
able to trigger some timeouts in some components.  Turns out that the
KVM_SET_GSI_ROUTING ioctl takes very long (strace claims up to 0.1 sec)
when having multiple CPUs.  This is caused by the  synchronize_rcu and
the HZ=100 of s390.  By changing the code to use a private srcu we can
speed things up.  This patch reduces the boot time till mounting root
from 8 to 2 seconds on my s390 guest with 100 disks.

Uses of hlist_for_each_entry_rcu, hlist_add_head_rcu, hlist_del_init_rcu
are fine because they do not have lockdep checks (hlist_for_each_entry_rcu
uses rcu_dereference_raw rather than rcu_dereference, and write-sides
do not do rcu lockdep at all).

Note that we're hardly relying on the "sleepable" part of srcu.  We just
want SRCU's faster detection of grace periods.

Testing was done by Andrew Theurer using netperf tests STREAM, MAERTS
and RR.  The difference between results "before" and "after" the patch
has mean -0.2% and standard deviation 0.6%.  Using a paired t-test on the
data points says that there is a 2.5% probability that the patch is the
cause of the performance difference (rather than a random fluctuation).

(Restricting the t-test to RR, which is the most likely to be affected,
changes the numbers to respectively -0.3% mean, 0.7% stdev, and 8%
probability that the numbers actually say something about the patch.
The probability increases mostly because there are fewer data points).

Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com> # s390
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-05 16:29:11 +02:00
Xiao Guangrong
a086f6a1eb Revert "KVM: Simplify kvm->tlbs_dirty handling"
This reverts commit 5befdc385d.

Since we will allow flush tlb out of mmu-lock in the later
patch

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2014-04-23 17:49:48 -03:00
Marcelo Tosatti
63b5cf04f4 Lazy storage key handling
-------------------------
 Linux does not use the ACC and F bits of the storage key. Newer Linux
 versions also do not use the storage keys for dirty and reference
 tracking. We can optimize the guest handling for those guests for faults
 as well as page-in and page-out by simply not caring about the guest
 visible storage key. We trap guest storage key instruction to enable
 those keys only on demand.
 
 Migration bitmap
 
 Until now s390 never provided a proper dirty bitmap.  Let's provide a
 proper migration bitmap for s390. We also change the user dirty tracking
 to a fault based mechanism. This makes the host completely independent
 from the storage keys. Long term this will allow us to back guest memory
 with large pages.
 
 per-VM device attributes
 ------------------------
 To avoid the introduction of new ioctls, let's provide the
 attribute semanantic also on the VM-"device".
 
 Userspace controlled CMMA
 -------------------------
 The CMMA assist is changed from "always on" to "on if requested" via
 per-VM device attributes. In addition a callback to reset all usage
 states is provided.
 
 Proper guest DAT handling for intercepts
 ----------------------------------------
 While instructions handled by SIE take care of all addressing aspects,
 KVM/s390 currently does not care about guest address translation of
 intercepts. This worked out fine, because
 - the s390 Linux kernel has a 1:1 mapping between kernel virtual<->real
  for all pages up to memory size
 - intercepts happen only for a small amount of cases
 - all of these intercepts happen to be in the kernel text for current
   distros
 
 Of course we need to be better for other intercepts, kernel modules etc.
 We provide the infrastructure and rework all in-kernel intercepts to work
 on logical addresses (paging etc) instead of real ones. The code has
 been running internally for several months now, so it is time for going
 public.
 
 GDB support
 -----------
 We provide breakpoints, single stepping and watchpoints.
 
 Fixes/Cleanups
 --------------
 - Improve program check delivery
 - Factor out the handling of transactional memory  on program checks
 - Use the existing define __LC_PGM_TDB
 - Several cleanups in the lowcore structure
 - Documentation
 
 NOTES
 -----
 - All patches touching base s390 are either ACKed or written by the s390
   maintainers
 - One base KVM patch "KVM: add kvm_is_error_gpa() helper"
 - One patch introduces the notion of VM device attributes
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Merge tag 'kvm-s390-20140422' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into queue

Lazy storage key handling
-------------------------
Linux does not use the ACC and F bits of the storage key. Newer Linux
versions also do not use the storage keys for dirty and reference
tracking. We can optimize the guest handling for those guests for faults
as well as page-in and page-out by simply not caring about the guest
visible storage key. We trap guest storage key instruction to enable
those keys only on demand.

Migration bitmap

Until now s390 never provided a proper dirty bitmap.  Let's provide a
proper migration bitmap for s390. We also change the user dirty tracking
to a fault based mechanism. This makes the host completely independent
from the storage keys. Long term this will allow us to back guest memory
with large pages.

per-VM device attributes
------------------------
To avoid the introduction of new ioctls, let's provide the
attribute semanantic also on the VM-"device".

Userspace controlled CMMA
-------------------------
The CMMA assist is changed from "always on" to "on if requested" via
per-VM device attributes. In addition a callback to reset all usage
states is provided.

Proper guest DAT handling for intercepts
----------------------------------------
While instructions handled by SIE take care of all addressing aspects,
KVM/s390 currently does not care about guest address translation of
intercepts. This worked out fine, because
- the s390 Linux kernel has a 1:1 mapping between kernel virtual<->real
 for all pages up to memory size
- intercepts happen only for a small amount of cases
- all of these intercepts happen to be in the kernel text for current
  distros

Of course we need to be better for other intercepts, kernel modules etc.
We provide the infrastructure and rework all in-kernel intercepts to work
on logical addresses (paging etc) instead of real ones. The code has
been running internally for several months now, so it is time for going
public.

GDB support
-----------
We provide breakpoints, single stepping and watchpoints.

Fixes/Cleanups
--------------
- Improve program check delivery
- Factor out the handling of transactional memory  on program checks
- Use the existing define __LC_PGM_TDB
- Several cleanups in the lowcore structure
- Documentation

NOTES
-----
- All patches touching base s390 are either ACKed or written by the s390
  maintainers
- One base KVM patch "KVM: add kvm_is_error_gpa() helper"
- One patch introduces the notion of VM device attributes

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

Conflicts:
	include/uapi/linux/kvm.h
2014-04-22 10:51:06 -03:00
Jason J. Herne
15f36ebd34 KVM: s390: Add proper dirty bitmap support to S390 kvm.
Replace the kvm_s390_sync_dirty_log() stub with code to construct the KVM
dirty_bitmap from S390 memory change bits.  Also add code to properly clear
the dirty_bitmap size when clearing the bitmap.

Signed-off-by: Jason J. Herne <jjherne@us.ibm.com>
CC: Dominik Dingel <dingel@linux.vnet.ibm.com>
[Dominik Dingel: use gmap_test_and_clear_dirty, locking fixes]
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-04-22 09:36:28 +02:00
Michael S. Tsirkin
68c3b4d167 KVM: VMX: speed up wildcard MMIO EVENTFD
With KVM, MMIO is much slower than PIO, due to the need to
do page walk and emulation. But with EPT, it does not have to be: we
know the address from the VMCS so if the address is unique, we can look
up the eventfd directly, bypassing emulation.

Unfortunately, this only works if userspace does not need to match on
access length and data.  The implementation adds a separate FAST_MMIO
bus internally. This serves two purposes:
    - minimize overhead for old userspace that does not use eventfd with lengtth = 0
    - minimize disruption in other code (since we don't know the length,
      devices on the MMIO bus only get a valid address in write, this
      way we don't need to touch all devices to teach them to handle
      an invalid length)

At the moment, this optimization only has effect for EPT on x86.

It will be possible to speed up MMIO for NPT and MMU using the same
idea in the future.

With this patch applied, on VMX MMIO EVENTFD is essentially as fast as PIO.
I was unable to detect any measureable slowdown to non-eventfd MMIO.

Making MMIO faster is important for the upcoming virtio 1.0 which
includes an MMIO signalling capability.

The idea was suggested by Peter Anvin.  Lots of thanks to Gleb for
pre-review and suggestions.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2014-04-17 14:01:43 -03:00
Linus Torvalds
7cbb39d4d4 Merge tag 'kvm-3.15-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm updates from Paolo Bonzini:
 "PPC and ARM do not have much going on this time.  Most of the cool
  stuff, instead, is in s390 and (after a few releases) x86.

  ARM has some caching fixes and PPC has transactional memory support in
  guests.  MIPS has some fixes, with more probably coming in 3.16 as
  QEMU will soon get support for MIPS KVM.

  For x86 there are optimizations for debug registers, which trigger on
  some Windows games, and other important fixes for Windows guests.  We
  now expose to the guest Broadwell instruction set extensions and also
  Intel MPX.  There's also a fix/workaround for OS X guests, nested
  virtualization features (preemption timer), and a couple kvmclock
  refinements.

  For s390, the main news is asynchronous page faults, together with
  improvements to IRQs (floating irqs and adapter irqs) that speed up
  virtio devices"

* tag 'kvm-3.15-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (96 commits)
  KVM: PPC: Book3S HV: Save/restore host PMU registers that are new in POWER8
  KVM: PPC: Book3S HV: Fix decrementer timeouts with non-zero TB offset
  KVM: PPC: Book3S HV: Don't use kvm_memslots() in real mode
  KVM: PPC: Book3S HV: Return ENODEV error rather than EIO
  KVM: PPC: Book3S: Trim top 4 bits of physical address in RTAS code
  KVM: PPC: Book3S HV: Add get/set_one_reg for new TM state
  KVM: PPC: Book3S HV: Add transactional memory support
  KVM: Specify byte order for KVM_EXIT_MMIO
  KVM: vmx: fix MPX detection
  KVM: PPC: Book3S HV: Fix KVM hang with CONFIG_KVM_XICS=n
  KVM: PPC: Book3S: Introduce hypervisor call H_GET_TCE
  KVM: PPC: Book3S HV: Fix incorrect userspace exit on ioeventfd write
  KVM: s390: clear local interrupts at cpu initial reset
  KVM: s390: Fix possible memory leak in SIGP functions
  KVM: s390: fix calculation of idle_mask array size
  KVM: s390: randomize sca address
  KVM: ioapic: reinject pending interrupts on KVM_SET_IRQCHIP
  KVM: Bump KVM_MAX_IRQ_ROUTES for s390
  KVM: s390: irq routing for adapter interrupts.
  KVM: s390: adapter interrupt sources
  ...
2014-04-02 14:50:10 -07:00
Michael Mueller
98f4a14676 KVM: add kvm_arch_vcpu_runnable() test to kvm_vcpu_on_spin() loop
Use the arch specific function kvm_arch_vcpu_runnable() to add a further
criterium to identify a suitable vcpu to yield to during undirected yield
processing.

Signed-off-by: Michael Mueller <mimu@linux.vnet.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-02-26 17:32:05 +01:00
Takuya Yoshikawa
5befdc385d KVM: Simplify kvm->tlbs_dirty handling
When this was introduced, kvm_flush_remote_tlbs() could be called
without holding mmu_lock.  It is now acknowledged that the function
must be called before releasing mmu_lock, and all callers have already
been changed to do so.

There is no need to use smp_mb() and cmpxchg() any more.

Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-02-18 10:07:26 +01:00
Andi Kleen
52480137d8 asmlinkage, kvm: Make kvm_rebooting visible
kvm_rebooting is referenced from assembler code, thus
needs to be visible.

Cc: Gleb Natapov <gleb@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Link: http://lkml.kernel.org/r/1391845930-28580-1-git-send-email-ak@linux.intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-02-13 18:11:56 -08:00
Jens Freimann
c05c4186bb KVM: s390: add floating irq controller
This patch adds a floating irq controller as a kvm_device.
It will be necessary for migration of floating interrupts as well
as for hardening the reset code by allowing user space to explicitly
remove all pending floating interrupts.

Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-01-30 10:25:20 +01:00
Linus Torvalds
7ebd3faa9b First round of KVM updates for 3.14; PPC parts will come next week.
Nothing major here, just bugfixes all over the place.  The most
 interesting part is the ARM guys' virtualized interrupt controller
 overhaul, which lets userspace get/set the state and thus enables
 migration of ARM VMs.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Paolo Bonzini:
 "First round of KVM updates for 3.14; PPC parts will come next week.

  Nothing major here, just bugfixes all over the place.  The most
  interesting part is the ARM guys' virtualized interrupt controller
  overhaul, which lets userspace get/set the state and thus enables
  migration of ARM VMs"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (67 commits)
  kvm: make KVM_MMU_AUDIT help text more readable
  KVM: s390: Fix memory access error detection
  KVM: nVMX: Update guest activity state field on L2 exits
  KVM: nVMX: Fix nested_run_pending on activity state HLT
  KVM: nVMX: Clean up handling of VMX-related MSRs
  KVM: nVMX: Add tracepoints for nested_vmexit and nested_vmexit_inject
  KVM: nVMX: Pass vmexit parameters to nested_vmx_vmexit
  KVM: nVMX: Leave VMX mode on clearing of feature control MSR
  KVM: VMX: Fix DR6 update on #DB exception
  KVM: SVM: Fix reading of DR6
  KVM: x86: Sync DR7 on KVM_SET_DEBUGREGS
  add support for Hyper-V reference time counter
  KVM: remove useless write to vcpu->hv_clock.tsc_timestamp
  KVM: x86: fix tsc catchup issue with tsc scaling
  KVM: x86: limit PIT timer frequency
  KVM: x86: handle invalid root_hpa everywhere
  kvm: Provide kvm_vcpu_eligible_for_directed_yield() stub
  kvm: vfio: silence GCC warning
  KVM: ARM: Remove duplicate include
  arm/arm64: KVM: relax the requirements of VMA alignment for THP
  ...
2014-01-22 21:40:43 -08:00
Scott Wood
4a55dd7273 kvm: Provide kvm_vcpu_eligible_for_directed_yield() stub
Commit 7940876e13 ("kvm: make local
functions static") broke KVM PPC builds due to removing (rather than
moving) the stub version of kvm_vcpu_eligible_for_directed_yield().

This patch reintroduces it.

Signed-off-by: Scott Wood <scottwood@freescale.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: Alexander Graf <agraf@suse.de>
[Move the #ifdef inside the function. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-01-15 12:03:23 +01:00
Stephen Hemminger
ea0269bc34 kvm: remove dead code
The function kvm_io_bus_read_cookie is defined but never used
in current in-tree code.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2014-01-08 19:03:00 -02:00
Stephen Hemminger
7940876e13 kvm: make local functions static
Running 'make namespacecheck' found lots of functions that
should be declared static, since only used in one file.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2014-01-08 19:02:58 -02:00
Christoffer Dall
7330672bef KVM: arm-vgic: Support KVM_CREATE_DEVICE for VGIC
Support creating the ARM VGIC device through the KVM_CREATE_DEVICE
ioctl, which can then later be leveraged to use the
KVM_{GET/SET}_DEVICE_ATTR, which is useful both for setting addresses in
a more generic API than the ARM-specific one and is useful for
save/restore of VGIC state.

Adds KVM_CAP_DEVICE_CTRL to ARM capabilities.

Note that we change the check for creating a VGIC from bailing out if
any VCPUs were created, to bailing out if any VCPUs were ever run.  This
is an important distinction that shouldn't break anything, but allows
creating the VGIC after the VCPUs have been created.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2013-12-21 10:01:16 -08:00
Takuya Yoshikawa
c08ac06ab3 KVM: Use cond_resched() directly and remove useless kvm_resched()
Since the commit 15ad7146 ("KVM: Use the scheduler preemption notifiers
to make kvm preemptible"), the remaining stuff in this function is a
simple cond_resched() call with an extra need_resched() check which was
there to avoid dropping VCPUs unnecessarily.  Now it is meaningless.

Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-12-13 14:23:45 +01:00
Andy Honig
338c7dbadd KVM: Improve create VCPU parameter (CVE-2013-4587)
In multiple functions the vcpu_id is used as an offset into a bitfield.  Ag
malicious user could specify a vcpu_id greater than 255 in order to set or
clear bits in kernel memory.  This could be used to elevate priveges in the
kernel.  This patch verifies that the vcpu_id provided is less than 255.
The api documentation already specifies that the vcpu_id must be less than
max_vcpus, but this is currently not checked.

Reported-by: Andrew Honig <ahonig@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Andrew Honig <ahonig@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-12-12 22:39:33 +01:00
Heiko Carstens
8a3caa6d74 KVM: kvm_clear_guest_page(): fix empty_zero_page usage
Using the address of 'empty_zero_page' as source address in order to
clear a page is wrong. On some architectures empty_zero_page is only the
pointer to the struct page of the empty_zero_page.  Therefore the clear
page operation would copy the contents of a couple of struct pages instead
of clearing a page.  For kvm only arm/arm64 are affected by this bug.

To fix this use the ZERO_PAGE macro instead which will return the struct
page address of the empty_zero_page on all architectures.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-11-21 11:19:32 +02:00
Linus Torvalds
f080480488 Here are the 3.13 KVM changes. There was a lot of work on the PPC
side: the HV and emulation flavors can now coexist in a single kernel
 is probably the most interesting change from a user point of view.
 On the x86 side there are nested virtualization improvements and a
 few bugfixes.  ARM got transparent huge page support, improved
 overcommit, and support for big endian guests.
 
 Finally, there is a new interface to connect KVM with VFIO.  This
 helps with devices that use NoSnoop PCI transactions, letting the
 driver in the guest execute WBINVD instructions.  This includes
 some nVidia cards on Windows, that fail to start without these
 patches and the corresponding userspace changes.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM changes from Paolo Bonzini:
 "Here are the 3.13 KVM changes.  There was a lot of work on the PPC
  side: the HV and emulation flavors can now coexist in a single kernel
  is probably the most interesting change from a user point of view.

  On the x86 side there are nested virtualization improvements and a few
  bugfixes.

  ARM got transparent huge page support, improved overcommit, and
  support for big endian guests.

  Finally, there is a new interface to connect KVM with VFIO.  This
  helps with devices that use NoSnoop PCI transactions, letting the
  driver in the guest execute WBINVD instructions.  This includes some
  nVidia cards on Windows, that fail to start without these patches and
  the corresponding userspace changes"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (146 commits)
  kvm, vmx: Fix lazy FPU on nested guest
  arm/arm64: KVM: PSCI: propagate caller endianness to the incoming vcpu
  arm/arm64: KVM: MMIO support for BE guest
  kvm, cpuid: Fix sparse warning
  kvm: Delete prototype for non-existent function kvm_check_iopl
  kvm: Delete prototype for non-existent function complete_pio
  hung_task: add method to reset detector
  pvclock: detect watchdog reset at pvclock read
  kvm: optimize out smp_mb after srcu_read_unlock
  srcu: API for barrier after srcu read unlock
  KVM: remove vm mmap method
  KVM: IOMMU: hva align mapping page size
  KVM: x86: trace cpuid emulation when called from emulator
  KVM: emulator: cleanup decode_register_operand() a bit
  KVM: emulator: check rex prefix inside decode_register()
  KVM: x86: fix emulation of "movzbl %bpl, %eax"
  kvm_host: typo fix
  KVM: x86: emulate SAHF instruction
  MAINTAINERS: add tree for kvm.git
  Documentation/kvm: add a 00-INDEX file
  ...
2013-11-15 13:51:36 +09:00
Gleb Natapov
80f5b5e700 KVM: remove vm mmap method
It was used in conjunction with KVM_SET_MEMORY_REGION ioctl which was
removed by b74a07beed in 2010, QEMU stopped using it in 2008, so
it is time to remove the code finally.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-11-06 09:28:47 +02:00
Gleb Natapov
95f328d3ad Merge branch 'kvm-ppc-queue' of git://github.com/agraf/linux-2.6 into queue
Conflicts:
	arch/powerpc/include/asm/processor.h
2013-11-04 10:20:57 +02:00
Alex Williamson
ec53500fae kvm: Add VFIO device
So far we've succeeded at making KVM and VFIO mostly unaware of each
other, but areas are cropping up where a connection beyond eventfds
and irqfds needs to be made.  This patch introduces a KVM-VFIO device
that is meant to be a gateway for such interaction.  The user creates
the device and can add and remove VFIO groups to it via file
descriptors.  When a group is added, KVM verifies the group is valid
and gets a reference to it via the VFIO external user interface.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-10-30 19:02:03 +01:00
Paolo Bonzini
0c8eb04a62 KVM: use a more sensible error number when debugfs directory creation fails
I don't know if this was due to cut and paste, or somebody was really
using a D20 to pick the error code for kvm_init_debugfs as suggested by
Linus (EFAULT is 14, so the possibility cannot be entirely ruled out).

In any case, this patch fixes it.

Reported-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-10-30 12:15:34 +01:00
Yang Zhang
e0230e1327 KVM: Mapping IOMMU pages after updating memslot
In kvm_iommu_map_pages(), we need to know the page size via call
kvm_host_page_size(). And it will check whether the target slot
is valid before return the right page size.
Currently, we will map the iommu pages when creating a new slot.
But we call kvm_iommu_map_pages() during preparing the new slot.
At that time, the new slot is not visible by domain(still in preparing).
So we cannot get the right page size from kvm_host_page_size() and
this will break the IOMMU super page logic.
The solution is to map the iommu pages after we insert the new slot
into domain.

Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com>
Tested-by: Patrick Lu <patrick.lu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-10-28 13:15:01 +01:00
Gleb Natapov
13acfd5715 Powerpc KVM work is based on a commit after rc4.
Merging master into next to satisfy the dependencies.

Conflicts:
	arch/arm/kvm/reset.c
2013-10-17 17:41:49 +03:00
Aneesh Kumar K.V
5587027ce9 kvm: Add struct kvm arg to memslot APIs
We will use that in the later patch to find the kvm ops handler

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
2013-10-17 15:49:23 +02:00
Aneesh Kumar K.V
2ba9f0d887 kvm: powerpc: book3s: Support building HV and PR KVM as module
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
[agraf: squash in compile fix]
Signed-off-by: Alexander Graf <agraf@suse.de>
2013-10-17 15:45:35 +02:00
Gleb Natapov
a2ac07fe29 Fix NULL dereference in gfn_to_hva_prot()
gfn_to_memslot() can return NULL or invalid slot. We need to check slot
validity before accessing it.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-10-03 10:08:52 +03:00
Paolo Bonzini
2f303b74a6 KVM: Convert kvm_lock back to non-raw spinlock
In commit e935b8372c ("KVM: Convert kvm_lock to raw_spinlock"),
the kvm_lock was made a raw lock.  However, the kvm mmu_shrink()
function tries to grab the (non-raw) mmu_lock within the scope of
the raw locked kvm_lock being held.  This leads to the following:

BUG: sleeping function called from invalid context at kernel/rtmutex.c:659
in_atomic(): 1, irqs_disabled(): 0, pid: 55, name: kswapd0
Preemption disabled at:[<ffffffffa0376eac>] mmu_shrink+0x5c/0x1b0 [kvm]

Pid: 55, comm: kswapd0 Not tainted 3.4.34_preempt-rt
Call Trace:
 [<ffffffff8106f2ad>] __might_sleep+0xfd/0x160
 [<ffffffff817d8d64>] rt_spin_lock+0x24/0x50
 [<ffffffffa0376f3c>] mmu_shrink+0xec/0x1b0 [kvm]
 [<ffffffff8111455d>] shrink_slab+0x17d/0x3a0
 [<ffffffff81151f00>] ? mem_cgroup_iter+0x130/0x260
 [<ffffffff8111824a>] balance_pgdat+0x54a/0x730
 [<ffffffff8111fe47>] ? set_pgdat_percpu_threshold+0xa7/0xd0
 [<ffffffff811185bf>] kswapd+0x18f/0x490
 [<ffffffff81070961>] ? get_parent_ip+0x11/0x50
 [<ffffffff81061970>] ? __init_waitqueue_head+0x50/0x50
 [<ffffffff81118430>] ? balance_pgdat+0x730/0x730
 [<ffffffff81060d2b>] kthread+0xdb/0xe0
 [<ffffffff8106e122>] ? finish_task_switch+0x52/0x100
 [<ffffffff817e1e94>] kernel_thread_helper+0x4/0x10
 [<ffffffff81060c50>] ? __init_kthread_worker+0x

After the previous patch, kvm_lock need not be a raw spinlock anymore,
so change it back.

Reported-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: kvm@vger.kernel.org
Cc: gleb@redhat.com
Cc: jan.kiszka@siemens.com
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-09-30 09:21:51 +02:00
Paolo Bonzini
4a937f96f3 KVM: protect kvm_usage_count with its own spinlock
The VM list need not be protected by a raw spinlock.  Separate the
two so that kvm_lock can be made non-raw.

Cc: kvm@vger.kernel.org
Cc: gleb@redhat.com
Cc: jan.kiszka@siemens.com
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-09-30 09:21:46 +02:00
Paolo Bonzini
4fa92fb25a KVM: cleanup (physical) CPU hotplug
Remove the useless argument, and do not do anything if there are no
VMs running at the time of the hotplug.

Cc: kvm@vger.kernel.org
Cc: gleb@redhat.com
Cc: jan.kiszka@siemens.com
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-09-30 09:21:30 +02:00
Paolo Bonzini
ba6a354154 KVM: mmu: allow page tables to be in read-only slots
Page tables in a read-only memory slot will currently cause a triple
fault because the page walker uses gfn_to_hva and it fails on such a slot.

OVMF uses such a page table; however, real hardware seems to be fine with
that as long as the accessed/dirty bits are set.  Save whether the slot
is readonly, and later check it when updating the accessed and dirty bits.

Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-09-17 12:52:31 +03:00
Paolo Bonzini
c21fbff16b KVM: rename __kvm_io_bus_sort_cmp to kvm_io_bus_cmp
This is the type-safe comparison function, so the double-underscore is
not related.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-08-28 09:39:40 +03:00
Andrea Arcangeli
11feeb4980 kvm: optimize away THP checks in kvm_is_mmio_pfn()
The checks on PG_reserved in the page structure on head and tail pages
aren't necessary because split_huge_page wouldn't transfer the
PG_reserved bit from head to tail anyway.

This was a forward-thinking check done in the case PageReserved was
set by a driver-owned page mapped in userland with something like
remap_pfn_range in a VM_PFNMAP region, but using hugepmds (not
possible right now). It was meant to be very safe, but it's overkill
as it's unlikely split_huge_page could ever run without the driver
noticing and tearing down the hugepage itself.

And if a driver in the future will really want to map a reserved
hugepage in userland using an huge pmd it should simply take care of
marking all subpages reserved too to keep KVM safe. This of course
would require such a hypothetical driver to tear down the huge pmd
itself and splitting the hugepage itself, instead of relaying on
split_huge_page, but that sounds very reasonable, especially
considering split_huge_page wouldn't currently transfer the reserved
bit anyway.

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-08-27 11:01:10 +03:00
Yann Droneaud
24009b0549 kvm: use anon_inode_getfd() with O_CLOEXEC flag
KVM uses anon_inode_get() to allocate file descriptors as part
of some of its ioctls. But those ioctls are lacking a flag argument
allowing userspace to choose options for the newly opened file descriptor.

In such case it's advised to use O_CLOEXEC by default so that
userspace is allowed to choose, without race, if the file descriptor
is going to be inherited across exec().

This patch set O_CLOEXEC flag on all file descriptors created
with anon_inode_getfd() to not leak file descriptors across exec().

Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
Link: http://lkml.kernel.org/r/cover.1377372576.git.ydroneaud@opteya.com
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-08-26 13:19:35 +03:00
Paolo Bonzini
a343c9b767 KVM: introduce __kvm_io_bus_sort_cmp
kvm_io_bus_sort_cmp is used also directly, not just as a callback for
sort and bsearch.  In these cases, it is handy to have a type-safe
variant.  This patch introduces such a variant, __kvm_io_bus_sort_cmp,
and uses it throughout kvm_main.c.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-07-29 09:01:14 +02:00
Takuya Yoshikawa
e59dbe09f8 KVM: Introduce kvm_arch_memslots_updated()
This is called right after the memslots is updated, i.e. when the result
of update_memslots() gets installed in install_new_memslots().  Since
the memslots needs to be updated twice when we delete or move a memslot,
kvm_arch_commit_memory_region() does not correspond to this exactly.

In the following patch, x86 will use this new API to check if the mmio
generation has reached its maximum value, in which case mmio sptes need
to be flushed out.

Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Acked-by: Alexander Graf <agraf@suse.de>
Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-07-18 12:29:25 +02:00
Cornelia Huck
126a5af520 KVM: kvm-io: support cookies
Add new functions kvm_io_bus_{read,write}_cookie() that allows users of
the kvm io infrastructure to use a cookie value to speed up lookup of a
device on an io bus.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-07-18 12:29:23 +02:00
Amos Kong
6ea34c9b78 kvm: exclude ioeventfd from counting kvm_io_range limit
We can easily reach the 1000 limit by start VM with a couple
hundred I/O devices (multifunction=on). The hardcode limit
already been adjusted 3 times (6 ~ 200 ~ 300 ~ 1000).

In userspace, we already have maximum file descriptor to
limit ioeventfd count. But kvm_io_bus devices also are used
for pit, pic, ioapic, coalesced_mmio. They couldn't be limited
by maximum file descriptor.

Currently only ioeventfds take too much kvm_io_bus devices,
so just exclude it from counting kvm_io_range limit.

Also fixed one indent issue in kvm_host.h

Signed-off-by: Amos Kong <akong@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-06-04 11:49:38 +03:00
Wei Yongjun
afc2f792cd KVM: add missing misc_deregister() on error in kvm_init()
Add the missing misc_deregister() before return from kvm_init()
in the debugfs init error handling case.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-05-12 12:06:24 +03:00
Linus Torvalds
c67723ebbb Merge tag 'kvm-3.10-2' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm fixes from Gleb Natapov:
 "Most of the fixes are in the emulator since now we emulate more than
  we did before for correctness sake we see more bugs there, but there
  is also an OOPS fixed and corruption of xcr0 register."

* tag 'kvm-3.10-2' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: emulator: emulate SALC
  KVM: emulator: emulate XLAT
  KVM: emulator: emulate AAM
  KVM: VMX: fix halt emulation while emulating invalid guest sate
  KVM: Fix kvm_irqfd_init initialization
  KVM: x86: fix maintenance of guest/host xcr0 state
2013-05-10 09:08:21 -07:00
Linus Torvalds
daf799cca8 Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus
Pull MIPS updates from Ralf Baechle:

 - More work on DT support for various platforms

 - Various fixes that were to late to make it straight into 3.9

 - Improved platform support, in particular the Netlogic XLR and
   BCM63xx, and the SEAD3 and Malta eval boards.

 - Support for several Ralink SOC families.

 - Complete support for the microMIPS ASE which basically reencodes the
   existing MIPS32/MIPS64 ISA to use non-constant size instructions.

 - Some fallout from LTO work which remove old cruft and will generally
   make the MIPS kernel easier to maintain and resistant to compiler
   optimization, even in absence of LTO.

 - KVM support.  While MIPS has announced hardware virtualization
   extensions this KVM extension uses trap and emulate mode for
   virtualization of MIPS32.  More KVM work to add support for VZ
   hardware virtualizaiton extensions and MIPS64 will probably already
   be merged for 3.11.

Most of this has been sitting in -next for a long time.  All defconfigs
have been build or run time tested except three for which fixes are being
sent by other maintainers.

Semantic conflict with kvm updates done as per Ralf

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (118 commits)
  MIPS: Add new GIC clockevent driver.
  MIPS: Formatting clean-ups for clocksources.
  MIPS: Refactor GIC clocksource code.
  MIPS: Move 'gic_frequency' to common location.
  MIPS: Move 'gic_present' to common location.
  MIPS: MIPS16e: Add unaligned access support.
  MIPS: MIPS16e: Support handling of delay slots.
  MIPS: MIPS16e: Add instruction formats.
  MIPS: microMIPS: Optimise 'strnlen' core library function.
  MIPS: microMIPS: Optimise 'strlen' core library function.
  MIPS: microMIPS: Optimise 'strncpy' core library function.
  MIPS: microMIPS: Optimise 'memset' core library function.
  MIPS: microMIPS: Add configuration option for microMIPS kernel.
  MIPS: microMIPS: Disable LL/SC and fix linker bug.
  MIPS: microMIPS: Add vdso support.
  MIPS: microMIPS: Add unaligned access support.
  MIPS: microMIPS: Support handling of delay slots.
  MIPS: microMIPS: Add support for exception handling.
  MIPS: microMIPS: Floating point support.
  MIPS: microMIPS: Fix macro naming in micro-assembler.
  ...
2013-05-10 07:48:05 -07:00
Ralf Baechle
5e0e61dd2c Merge branch 'next/kvm' into mips-for-linux-next 2013-05-09 17:56:40 +02:00
Sanjay Lal
2f4d9b5442 KVM/MIPS32: Do not call vcpu_load when injecting interrupts.
Signed-off-by: Sanjay Lal <sanjayl@kymasys.com>
Cc: kvm@vger.kernel.org
Cc: linux-mips@linux-mips.org
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-05-09 17:48:22 +02:00
Asias He
7dac16c379 KVM: Fix kvm_irqfd_init initialization
In commit a0f155e96 'KVM: Initialize irqfd from kvm_init()', when
kvm_init() is called the second time (e.g kvm-amd.ko and kvm-intel.ko),
kvm_arch_init() will fail with -EEXIST, then kvm_irqfd_exit() will be
called on the error handling path. This way, the kvm_irqfd system will
not be ready.

This patch fix the following:

BUG: unable to handle kernel NULL pointer dereference at           (null)
IP: [<ffffffff81c0721e>] _raw_spin_lock+0xe/0x30
PGD 0
Oops: 0002 [#1] SMP
Modules linked in: vhost_net
CPU 6
Pid: 4257, comm: qemu-system-x86 Not tainted 3.9.0-rc3+ #757 Dell Inc. OptiPlex 790/0V5HMK
RIP: 0010:[<ffffffff81c0721e>]  [<ffffffff81c0721e>] _raw_spin_lock+0xe/0x30
RSP: 0018:ffff880221721cc8  EFLAGS: 00010046
RAX: 0000000000000100 RBX: ffff88022dcc003f RCX: ffff880221734950
RDX: ffff8802208f6ca8 RSI: 000000007fffffff RDI: 0000000000000000
RBP: ffff880221721cc8 R08: 0000000000000002 R09: 0000000000000002
R10: 00007f7fd01087e0 R11: 0000000000000246 R12: ffff8802208f6ca8
R13: 0000000000000080 R14: ffff880223e2a900 R15: 0000000000000000
FS:  00007f7fd38488e0(0000) GS:ffff88022dcc0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000022309f000 CR4: 00000000000427e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process qemu-system-x86 (pid: 4257, threadinfo ffff880221720000, task ffff880222bd5640)
Stack:
 ffff880221721d08 ffffffff810ac5c5 ffff88022431dc00 0000000000000086
 0000000000000080 ffff880223e2a900 ffff8802208f6ca8 0000000000000000
 ffff880221721d48 ffffffff810ac8fe 0000000000000000 ffff880221734000
Call Trace:
 [<ffffffff810ac5c5>] __queue_work+0x45/0x2d0
 [<ffffffff810ac8fe>] queue_work_on+0x8e/0xa0
 [<ffffffff810ac949>] queue_work+0x19/0x20
 [<ffffffff81009b6b>] irqfd_deactivate+0x4b/0x60
 [<ffffffff8100a69d>] kvm_irqfd+0x39d/0x580
 [<ffffffff81007a27>] kvm_vm_ioctl+0x207/0x5b0
 [<ffffffff810c9545>] ? update_curr+0xf5/0x180
 [<ffffffff811b66e8>] do_vfs_ioctl+0x98/0x550
 [<ffffffff810c1f5e>] ? finish_task_switch+0x4e/0xe0
 [<ffffffff81c054aa>] ? __schedule+0x2ea/0x710
 [<ffffffff811b6bf7>] sys_ioctl+0x57/0x90
 [<ffffffff8140ae9e>] ? trace_hardirqs_on_thunk+0x3a/0x3c
 [<ffffffff81c0f602>] system_call_fastpath+0x16/0x1b
Code: c1 ea 08 38 c2 74 0f 66 0f 1f 44 00 00 f3 90 0f b6 03 38 c2 75 f7 48 83 c4 08 5b c9 c3 55 48 89 e5 66 66 66 66 90 b8 00 01 00 00 <f0> 66 0f c1 07 89 c2 66 c1 ea 08 38 c2 74 0c 0f 1f 00 f3 90 0f
RIP  [<ffffffff81c0721e>] _raw_spin_lock+0xe/0x30
RSP <ffff880221721cc8>
CR2: 0000000000000000
---[ end trace 13fb1e4b6e5ab21f ]---

Signed-off-by: Asias He <asias@redhat.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-05-08 13:15:35 +03:00
Linus Torvalds
01227a889e Merge tag 'kvm-3.10-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm updates from Gleb Natapov:
 "Highlights of the updates are:

  general:
   - new emulated device API
   - legacy device assignment is now optional
   - irqfd interface is more generic and can be shared between arches

  x86:
   - VMCS shadow support and other nested VMX improvements
   - APIC virtualization and Posted Interrupt hardware support
   - Optimize mmio spte zapping

  ppc:
    - BookE: in-kernel MPIC emulation with irqfd support
    - Book3S: in-kernel XICS emulation (incomplete)
    - Book3S: HV: migration fixes
    - BookE: more debug support preparation
    - BookE: e6500 support

  ARM:
   - reworking of Hyp idmaps

  s390:
   - ioeventfd for virtio-ccw

  And many other bug fixes, cleanups and improvements"

* tag 'kvm-3.10-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (204 commits)
  kvm: Add compat_ioctl for device control API
  KVM: x86: Account for failing enable_irq_window for NMI window request
  KVM: PPC: Book3S: Add API for in-kernel XICS emulation
  kvm/ppc/mpic: fix missing unlock in set_base_addr()
  kvm/ppc: Hold srcu lock when calling kvm_io_bus_read/write
  kvm/ppc/mpic: remove users
  kvm/ppc/mpic: fix mmio region lists when multiple guests used
  kvm/ppc/mpic: remove default routes from documentation
  kvm: KVM_CAP_IOMMU only available with device assignment
  ARM: KVM: iterate over all CPUs for CPU compatibility check
  KVM: ARM: Fix spelling in error message
  ARM: KVM: define KVM_ARM_MAX_VCPUS unconditionally
  KVM: ARM: Fix API documentation for ONE_REG encoding
  ARM: KVM: promote vfp_host pointer to generic host cpu context
  ARM: KVM: add architecture specific hook for capabilities
  ARM: KVM: perform HYP initilization for hotplugged CPUs
  ARM: KVM: switch to a dual-step HYP init code
  ARM: KVM: rework HYP page table freeing
  ARM: KVM: enforce maximum size for identity mapped code
  ARM: KVM: move to a KVM provided HYP idmap
  ...
2013-05-05 14:47:31 -07:00
Scott Wood
db6ae61581 kvm: Add compat_ioctl for device control API
This API shouldn't have 32/64-bit issues, but VFS assumes it does
unless told otherwise.

Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-05-05 12:14:15 +03:00
Paul Mackerras
5975a2e095 KVM: PPC: Book3S: Add API for in-kernel XICS emulation
This adds the API for userspace to instantiate an XICS device in a VM
and connect VCPUs to it.  The API consists of a new device type for
the KVM_CREATE_DEVICE ioctl, a new capability KVM_CAP_IRQ_XICS, which
functions similarly to KVM_CAP_IRQ_MPIC, and the KVM_IRQ_LINE ioctl,
which is used to assert and deassert interrupt inputs of the XICS.

The XICS device has one attribute group, KVM_DEV_XICS_GRP_SOURCES.
Each attribute within this group corresponds to the state of one
interrupt source.  The attribute number is the same as the interrupt
source number.

This does not support irq routing or irqfd yet.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>
2013-05-02 15:28:36 +02:00
Scott Wood
07f0a7bdec kvm: destroy emulated devices on VM exit
The hassle of getting refcounting right was greater than the hassle
of keeping a list of devices to destroy on VM exit.

Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
2013-04-26 20:27:28 +02:00
Scott Wood
5df554ad5b kvm/ppc/mpic: in-kernel MPIC emulation
Hook the MPIC code up to the KVM interfaces, add locking, etc.

Signed-off-by: Scott Wood <scottwood@freescale.com>
[agraf: add stub function for kvmppc_mpic_set_epr, non-booke, 64bit]
Signed-off-by: Alexander Graf <agraf@suse.de>
2013-04-26 20:27:23 +02:00
Scott Wood
852b6d57dc kvm: add device control API
Currently, devices that are emulated inside KVM are configured in a
hardcoded manner based on an assumption that any given architecture
only has one way to do it.  If there's any need to access device state,
it is done through inflexible one-purpose-only IOCTLs (e.g.
KVM_GET/SET_LAPIC).  Defining new IOCTLs for every little thing is
cumbersome and depletes a limited numberspace.

This API provides a mechanism to instantiate a device of a certain
type, returning an ID that can be used to set/get attributes of the
device.  Attributes may include configuration parameters (e.g.
register base address), device state, operational commands, etc.  It
is similar to the ONE_REG API, except that it acts on devices rather
than vcpus.

Both device types and individual attributes can be tested without having
to create the device or get/set the attribute, without the need for
separately managing enumerated capabilities.

Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
2013-04-26 20:27:20 +02:00
Alexander Graf
7df35f5496 KVM: Move irqfd resample cap handling to generic code
Now that we have most irqfd code completely platform agnostic, let's move
irqfd's resample capability return to generic code as well.

Signed-off-by: Alexander Graf <agraf@suse.de>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
2013-04-26 20:27:19 +02:00
Alexander Graf
aa8d5944b8 KVM: Move irq routing to generic code
The IRQ routing set ioctl lives in the hacky device assignment code inside
of KVM today. This is definitely the wrong place for it. Move it to the much
more natural kvm_main.c.

Signed-off-by: Alexander Graf <agraf@suse.de>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
2013-04-26 20:27:17 +02:00
Alexander Graf
a725d56a02 KVM: Introduce CONFIG_HAVE_KVM_IRQ_ROUTING
Quite a bit of code in KVM has been conditionalized on availability of
IOAPIC emulation. However, most of it is generically applicable to
platforms that don't have an IOPIC, but a different type of irq chip.

Make code that only relies on IRQ routing, not an APIC itself, on
CONFIG_HAVE_KVM_IRQ_ROUTING, so that we can reuse it later.

Signed-off-by: Alexander Graf <agraf@suse.de>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
2013-04-26 20:27:14 +02:00
Yang Zhang
a20ed54d6e KVM: VMX: Add the deliver posted interrupt algorithm
Only deliver the posted interrupt when target vcpu is running
and there is no previous interrupt pending in pir.

Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com>
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-04-16 16:32:40 -03:00
Yang Zhang
3d81bc7e96 KVM: Call common update function when ioapic entry changed.
Both TMR and EOI exit bitmap need to be updated when ioapic changed
or vcpu's id/ldr/dfr changed. So use common function instead eoi exit
bitmap specific function.

Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com>
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-04-16 16:32:40 -03:00
Yang Zhang
aa2fbe6d44 KVM: Let ioapic know the irq line status
Userspace may deliver RTC interrupt without query the status. So we
want to track RTC EOI for this case.

Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com>
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-04-15 23:20:34 -03:00
Geoff Levand
e3ba45b804 KVM: Move kvm_spurious_fault to x86.c
The routine kvm_spurious_fault() is an x86 specific routine, so
move it from virt/kvm/kvm_main.c to arch/x86/kvm/x86.c.

Fixes this sparse warning when building on arm64:

  virt/kvm/kvm_main.c⚠️ symbol 'kvm_spurious_fault' was not declared. Should it be static?

Signed-off-by: Geoff Levand <geoff@infradead.org>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-04-08 13:02:06 +03:00
Geoff Levand
39369f7a8b KVM: Make local routines static
The routines get_user_page_nowait(), kvm_io_bus_sort_cmp(), kvm_io_bus_insert_dev()
and kvm_io_bus_get_first_dev() are only referenced within kvm_main.c, so give them
static linkage.

Fixes sparse warnings like these:

  virt/kvm/kvm_main.c: warning: symbol 'get_user_page_nowait' was not declared. Should it be static?

Signed-off-by: Geoff Levand <geoff@infradead.org>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-04-08 13:02:04 +03:00
Andrew Honig
8f964525a1 KVM: Allow cross page reads and writes from cached translations.
This patch adds support for kvm_gfn_to_hva_cache_init functions for
reads and writes that will cross a page.  If the range falls within
the same memslot, then this will be a fast operation.  If the range
is split between two memslots, then the slower kvm_read_guest and
kvm_write_guest are used.

Tested: Test against kvm_clock unit tests.

Signed-off-by: Andrew Honig <ahonig@google.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-04-07 13:05:35 +03:00
Raghavendra K T
7bc7ae25b1 kvm: Iterate over only vcpus that are preempted
This helps in filtering out the eligible candidates further and
thus potentially helps in quickly allowing preempted lockholders to run.
Note that if a vcpu was spinning during preemption we filter them
by checking whether they are preempted due to pause loop exit.

Reviewed-by: Chegu Vinod <chegu_vinod@hp.com>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-03-11 11:37:22 +02:00
Raghavendra K T
3a08a8f9f0 kvm: Record the preemption status of vcpus using preempt notifiers
Note that we mark as preempted only when vcpu's task state was
Running during preemption.

Thanks Jiannan, Avi for preemption notifier ideas. Thanks Gleb, PeterZ
for their precious suggestions. Thanks Srikar for an idea on avoiding
rcu lock while checking task state that improved overcommit numbers.

Reviewed-by: Chegu Vinod <chegu_vinod@hp.com>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-03-11 11:37:08 +02:00
Cornelia Huck
a0f155e964 KVM: Initialize irqfd from kvm_init().
Currently, eventfd introduces module_init/module_exit functions
to initialize/cleanup the irqfd workqueue. This only works, however,
if no other module_init/module_exit functions are built into the
same module.

Let's just move the initialization and cleanup to kvm_init and kvm_exit.
This way, it is also clearer where kvm startup may fail.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-03-05 19:12:16 -03:00
Takuya Yoshikawa
8482644aea KVM: set_memory_region: Refactor commit_memory_region()
This patch makes the parameter old a const pointer to the old memory
slot and adds a new parameter named change to know the change being
requested: the former is for removing extra copying and the latter is
for cleaning up the code.

Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-03-04 20:21:08 -03:00
Takuya Yoshikawa
7b6195a91d KVM: set_memory_region: Refactor prepare_memory_region()
This patch drops the parameter old, a copy of the old memory slot, and
adds a new parameter named change to know the change being requested.

This not only cleans up the code but also removes extra copying of the
memory slot structure.

Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-03-04 20:21:08 -03:00
Takuya Yoshikawa
74d0727cb7 KVM: set_memory_region: Make kvm_mr_change available to arch code
This will be used for cleaning up prepare/commit_memory_region() later.

Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-03-04 20:21:08 -03:00
Takuya Yoshikawa
47ae31e257 KVM: set_memory_region: Drop user_alloc from set_memory_region()
Except ia64's stale code, KVM_SET_MEMORY_REGION support, this is only
used for sanity checks in __kvm_set_memory_region() which can easily
be changed to use slot id instead.

Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-03-04 20:21:08 -03:00
Takuya Yoshikawa
462fce4606 KVM: set_memory_region: Drop user_alloc from prepare/commit_memory_region()
X86 does not use this any more.  The remaining user, s390's !user_alloc
check, can be simply removed since KVM_SET_MEMORY_REGION ioctl is no
longer supported.

Note: fixed powerpc's indentations with spaces to suppress checkpatch
errors.

Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-03-04 20:21:08 -03:00
Takuya Yoshikawa
7a905b1485 KVM: Remove user_alloc from struct kvm_memory_slot
This field was needed to differentiate memory slots created by the new
API, KVM_SET_USER_MEMORY_REGION, from those by the old equivalent,
KVM_SET_MEMORY_REGION, whose support was dropped long before:

  commit b74a07beed
  KVM: Remove kernel-allocated memory regions

Although we also have private memory slots to which KVM allocates
memory with vm_mmap(), !user_alloc slots in other words, the slot id
should be enough for differentiating them.

Note: corresponding function parameters will be removed later.

Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-02-11 11:52:00 +02:00
Takuya Yoshikawa
75d61fbcf5 KVM: set_memory_region: Disallow changing read-only attribute later
As Xiao pointed out, there are a few problems with it:
 - kvm_arch_commit_memory_region() write protects the memory slot only
   for GET_DIRTY_LOG when modifying the flags.
 - FNAME(sync_page) uses the old spte value to set a new one without
   checking KVM_MEM_READONLY flag.

Since we flush all shadow pages when creating a new slot, the simplest
fix is to disallow such problematic flag changes: this is safe because
no one is doing such things.

Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-02-04 22:56:47 -02:00
Takuya Yoshikawa
f64c039893 KVM: set_memory_region: Identify the requested change explicitly
KVM_SET_USER_MEMORY_REGION forces __kvm_set_memory_region() to identify
what kind of change is being requested by checking the arguments.  The
current code does this checking at various points in code and each
condition being used there is not easy to understand at first glance.

This patch consolidates these checks and introduces an enum to name the
possible changes to clean up the code.

Although this does not introduce any functional changes, there is one
change which optimizes the code a bit: if we have nothing to change, the
new code returns 0 immediately.

Note that the return value for this case cannot be changed since QEMU
relies on it: we noticed this when we changed it to -EINVAL and got a
section mismatch error at the final stage of live migration.

Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-02-04 22:00:53 -02:00
Raghavendra K T
c45c528e89 kvm: Handle yield_to failure return code for potential undercommit case
yield_to returns -ESRCH, When source and target of yield_to
run queue length is one. When we see three successive failures of
yield_to we assume we are in potential undercommit case and abort
from PLE handler.
The assumption is backed by low probability of wrong decision
for even worst case scenarios such as average runqueue length
between 1 and 2.

More detail on rationale behind using three tries:
if p is the probability of finding rq length one on a particular cpu,
and if we do n tries, then probability of exiting ple handler is:

 p^(n+1) [ because we would have come across one source with rq length
1 and n target cpu rqs  with length 1 ]

so
num tries:         probability of aborting ple handler (1.5x overcommit)
 1                 1/4
 2                 1/8
 3                 1/16

We can increase this probability with more tries, but the problem is
the overhead.
Also, If we have tried three times that means we would have iterated
over 3 good eligible vcpus along with many non-eligible candidates. In
worst case if we iterate all the vcpus, we reduce 1x performance and
overcommit performance get hit.

note that we do not update last boosted vcpu in failure cases.
Thank Avi for raising question on aborting after first fail from yield_to.

Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Tested-by: Chegu Vinod <chegu_vinod@hp.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-01-29 15:38:45 +02:00
Yang Zhang
c7c9c56ca2 x86, apicv: add virtual interrupt delivery support
Virtual interrupt delivery avoids KVM to inject vAPIC interrupts
manually, which is fully taken care of by the hardware. This needs
some special awareness into existing interrupr injection path:

- for pending interrupt, instead of direct injection, we may need
  update architecture specific indicators before resuming to guest.

- A pending interrupt, which is masked by ISR, should be also
  considered in above update action, since hardware will decide
  when to inject it at right time. Current has_interrupt and
  get_interrupt only returns a valid vector from injection p.o.v.

Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-01-29 10:48:19 +02:00
Alex Williamson
261874b0d5 kvm: Force IOMMU remapping on memory slot read-only flag changes
Memory slot flags can be altered without changing other parameters of
the slot.  The read-only attribute is the only one the IOMMU cares
about, so generate an un-map, re-map when this occurs.  This also
avoid unnecessarily re-mapping the slot when no IOMMU visible changes
are made.

Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-01-27 12:41:30 +02:00
Takuya Yoshikawa
a843fac253 KVM: set_memory_region: Remove unnecessary variable memslot
One such variable, slot, is enough for holding a pointer temporarily.
We also remove another local variable named slot, which is limited in
a block, since it is confusing to have the same name in this function.

Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-01-17 14:27:59 +02:00
Takuya Yoshikawa
0a706beefb KVM: set_memory_region: Don't check for overlaps unless we create or move a slot
Don't need the check for deleting an existing slot or just modifiying
the flags.

Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-01-17 14:27:50 +02:00
Takuya Yoshikawa
0ea75e1d26 KVM: set_memory_region: Don't jump to out_free unnecessarily
This makes the separation between the sanity checks and the rest of the
code a bit clearer.

Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-01-17 14:27:43 +02:00
Takuya Yoshikawa
c972f3b125 KVM: Write protect the updated slot only when dirty logging is enabled
Calling kvm_mmu_slot_remove_write_access() for a deleted slot does
nothing but search for non-existent mmu pages which have mappings to
that deleted memory; this is safe but a waste of time.

Since we want to make the function rmap based in a later patch, in a
manner which makes it unsafe to be called for a deleted slot, we makes
the caller see if the slot is non-zero and being dirty logged.

Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-01-14 11:13:15 +02:00
Gleb Natapov
7ec4fb4496 KVM: move the code that installs new slots array to a separate function.
Move repetitive code sequence to a separate function.

Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
2012-12-24 17:49:30 +02:00
Alex Williamson
116c14c019 kvm: Fix memory slot generation updates
Previous patch "kvm: Minor memory slot optimization" (b7f69c555c)
overlooked the generation field of the memory slots.  Re-using the
original memory slots left us with with two slightly different memory
slots with the same generation.  To fix this, make update_memslots()
take a new parameter to specify the last generation.  This also makes
generation management more explicit to avoid such problems in the future.

Reported-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
2012-12-23 10:17:38 +02:00
Alex Williamson
1e702d9af5 KVM: struct kvm_memory_slot.id -> short
We're currently offering a whopping 32 memory slots to user space, an
int is a bit excessive for storing this.  We would like to increase
our memslots, but SHRT_MAX should be more than enough.

Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-12-13 23:25:24 -02:00
Alex Williamson
f82a8cfe93 KVM: struct kvm_memory_slot.user_alloc -> bool
There's no need for this to be an int, it holds a boolean.
Move to the end of the struct for alignment.

Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-12-13 23:24:38 -02:00
Alex Williamson
bbacc0c111 KVM: Rename KVM_MEMORY_SLOTS -> KVM_USER_MEM_SLOTS
It's easy to confuse KVM_MEMORY_SLOTS and KVM_MEM_SLOTS_NUM.  One is
the user accessible slots and the other is user + private.  Make this
more obvious.

Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-12-13 23:21:57 -02:00
Alex Williamson
b7f69c555c KVM: Minor memory slot optimization
If a slot is removed or moved in the guest physical address space, we
first allocate and install a new slot array with the invalidated
entry.  The old array is then freed.  We then proceed to allocate yet
another slot array to install the permanent replacement.  Re-use the
original array when this occurs and avoid the extra kfree/kmalloc.

Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-12-13 23:21:53 -02:00
Alex Williamson
e40f193f5b KVM: Fix iommu map/unmap to handle memory slot moves
The iommu integration into memory slots expects memory slots to be
added or removed and doesn't handle the move case.  We can unmap
slots from the iommu after we mark them invalid and map them before
installing the final memslot array.  Also re-order the kmemdup vs
map so we don't leave iommu mappings if we get ENOMEM.

Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-12-13 23:21:52 -02:00
Alex Williamson
9c695d42db KVM: Check userspace_addr when modifying a memory slot
The API documents that only flags and guest physical memory space can
be modified on an existing slot, but we don't enforce that the
userspace address cannot be modified.  Instead we just ignore it.
This means that a user may think they've successfully moved both the
guest and user addresses, when in fact only the guest address changed.
Check and error instead.

Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-12-13 23:21:51 -02:00
Alex Williamson
f0736cf055 KVM: Restrict non-existing slot state transitions
The API documentation states:

	When changing an existing slot, it may be moved in the guest
	physical memory space, or its flags may be modified.

An "existing slot" requires a non-zero npages (memory_size).  The only
transition we should therefore allow for a non-existing slot should be
to create the slot, which includes setting a non-zero memory_size.  We
currently allow calls to modify non-existing slots, which is pointless,
confusing, and possibly wrong.

With this we know that the invalidation path of __kvm_set_memory_region
is always for a delete or move and never for adding a zero size slot.

Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-12-13 23:21:50 -02:00
Alex Williamson
5419369ed6 KVM: Fix user memslot overlap check
Prior to memory slot sorting this loop compared all of the user memory
slots for overlap with new entries.  With memory slot sorting, we're
just checking some number of entries in the array that may or may not
be user slots.  Instead, walk all the slots with kvm_for_each_memslot,
which has the added benefit of terminating early when we hit the first
empty slot, and skip comparison to private slots.

Cc: stable@vger.kernel.org
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-29 23:30:32 -02:00
Marcelo Tosatti
42897d866b KVM: x86: add kvm_arch_vcpu_postcreate callback, move TSC initialization
TSC initialization will soon make use of online_vcpus.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-27 23:29:14 -02:00
Marcelo Tosatti
d828199e84 KVM: x86: implement PVCLOCK_TSC_STABLE_BIT pvclock flag
KVM added a global variable to guarantee monotonicity in the guest.
One of the reasons for that is that the time between

	1. ktime_get_ts(&timespec);
	2. rdtscll(tsc);

Is variable. That is, given a host with stable TSC, suppose that
two VCPUs read the same time via ktime_get_ts() above.

The time required to execute 2. is not the same on those two instances
executing in different VCPUS (cache misses, interrupts...).

If the TSC value that is used by the host to interpolate when
calculating the monotonic time is the same value used to calculate
the tsc_timestamp value stored in the pvclock data structure, and
a single <system_timestamp, tsc_timestamp> tuple is visible to all
vcpus simultaneously, this problem disappears. See comment on top
of pvclock_update_vm_gtod_copy for details.

Monotonicity is then guaranteed by synchronicity of the host TSCs
and guest TSCs.

Set TSC stable pvclock flag in that case, allowing the guest to read
clock from userspace.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-27 23:29:13 -02:00
Guo Chao
807f12e57c KVM: remove unnecessary return value check
No need to check return value before breaking switch.

Signed-off-by: Guo Chao <yan@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-13 22:14:29 -02:00
Guo Chao
18595411a7 KVM: do not kfree error pointer
We should avoid kfree()ing error pointer in kvm_vcpu_ioctl() and
kvm_arch_vcpu_ioctl().

Signed-off-by: Guo Chao <yan@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-13 22:14:28 -02:00
Xiao Guangrong
81c52c56e2 KVM: do not treat noslot pfn as a error pfn
This patch filters noslot pfn out from error pfns based on Marcelo comment:
noslot pfn is not a error pfn

After this patch,
- is_noslot_pfn indicates that the gfn is not in slot
- is_error_pfn indicates that the gfn is in slot but the error is occurred
  when translate the gfn to pfn
- is_error_noslot_pfn indicates that the pfn either it is error pfns or it
  is noslot pfn
And is_invalid_pfn can be removed, it makes the code more clean

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-10-29 20:31:04 -02:00
Linus Torvalds
3d0ceac129 KVM updates for 3.7-rc2
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Merge tag 'kvm-3.7-2' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm fixes from Avi Kivity:
 "KVM updates for 3.7-rc2"

* tag 'kvm-3.7-2' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM guest: exit idleness when handling KVM_PV_REASON_PAGE_NOT_PRESENT
  KVM: apic: fix LDR calculation in x2apic mode
  KVM: MMU: fix release noslot pfn
2012-10-24 04:08:42 +03:00
Xiao Guangrong
f3ac1a4b66 KVM: MMU: fix release noslot pfn
We can not directly call kvm_release_pfn_clean to release the pfn
since we can meet noslot pfn which is used to cache mmio info into
spte

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-10-22 18:03:25 +02:00
Takuya Yoshikawa
b74ca3b3fd kvm: replace test_and_set_bit_le() in mark_page_dirty_in_slot() with set_bit_le()
Now that we have defined generic set_bit_le() we do not need to use
test_and_set_bit_le() for atomically setting a bit.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Cc: Avi Kivity <avi@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-06 03:04:56 +09:00
Linus Torvalds
ecefbd94b8 KVM updates for the 3.7 merge window
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Merge tag 'kvm-3.7-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Avi Kivity:
 "Highlights of the changes for this release include support for vfio
  level triggered interrupts, improved big real mode support on older
  Intels, a streamlines guest page table walker, guest APIC speedups,
  PIO optimizations, better overcommit handling, and read-only memory."

* tag 'kvm-3.7-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (138 commits)
  KVM: s390: Fix vcpu_load handling in interrupt code
  KVM: x86: Fix guest debug across vcpu INIT reset
  KVM: Add resampling irqfds for level triggered interrupts
  KVM: optimize apic interrupt delivery
  KVM: MMU: Eliminate pointless temporary 'ac'
  KVM: MMU: Avoid access/dirty update loop if all is well
  KVM: MMU: Eliminate eperm temporary
  KVM: MMU: Optimize is_last_gpte()
  KVM: MMU: Simplify walk_addr_generic() loop
  KVM: MMU: Optimize pte permission checks
  KVM: MMU: Update accessed and dirty bits after guest pagetable walk
  KVM: MMU: Move gpte_access() out of paging_tmpl.h
  KVM: MMU: Optimize gpte_access() slightly
  KVM: MMU: Push clean gpte write protection out of gpte_access()
  KVM: clarify kvmclock documentation
  KVM: make processes waiting on vcpu mutex killable
  KVM: SVM: Make use of asm.h
  KVM: VMX: Make use of asm.h
  KVM: VMX: Make lto-friendly
  KVM: x86: lapic: Clean up find_highest_vector() and count_vectors()
  ...

Conflicts:
	arch/s390/include/asm/processor.h
	arch/x86/kvm/i8259.c
2012-10-04 09:30:33 -07:00
Michael S. Tsirkin
9fc77441e5 KVM: make processes waiting on vcpu mutex killable
vcpu mutex can be held for unlimited time so
taking it with mutex_lock on an ioctl is wrong:
one process could be passed a vcpu fd and
call this ioctl on the vcpu used by another process,
it will then be unkillable until the owner exits.

Call mutex_lock_killable instead and return status.
Note: mutex_lock_interruptible would be even nicer,
but I am not sure all users are prepared to handle EINTR
from these ioctls. They might misinterpret it as an error.

Cleanup paths expect a vcpu that can't be used by
any userspace so this will always succeed - catch bugs
by calling BUG_ON.

Catch callers that don't check return state by adding
__must_check.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-09-17 13:46:32 -03:00
Marcelo Tosatti
3b4dc3a031 KVM: move postcommit flush to x86, as mmio sptes are x86 specific
Other arches do not need this.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

v2: fix incorrect deletion of mmio sptes on gpa move (noticed by Takuya)
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-09-06 16:37:30 +03:00
Marcelo Tosatti
12d6e7538e KVM: perform an invalid memslot step for gpa base change
PPC must flush all translations before the new memory slot
is visible.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-09-06 16:37:27 +03:00
Marcelo Tosatti
2df72e9bc4 KVM: split kvm_arch_flush_shadow
Introducing kvm_arch_flush_shadow_memslot, to invalidate the
translations of a single memory slot.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-09-06 16:37:25 +03:00
Gavin Shan
66a03505a7 KVM: PPC: book3s: fix build error caused by gfn_to_hva_memslot()
The build error was caused by that builtin functions are calling
the functions implemented in modules. This error was introduced by
commit 4d8b81abc4 ("KVM: introduce readonly memslot").

The patch fixes the build error by moving function __gfn_to_hva_memslot()
from kvm_main.c to kvm_host.h and making that "inline" so that the
builtin function (kvmppc_h_enter) can use that.

Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-08-27 16:44:20 -03:00
Alan Cox
760a9a30ad kvm: Fix nonsense handling of compat ioctl
KVM_SET_SIGNAL_MASK passed a NULL argument leaves the on stack signal
sets uninitialized. It then passes them through to
kvm_vcpu_ioctl_set_sigmask.

We should be passing a NULL in this case not translated garbage.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-08-26 15:11:48 -03:00
Xiao Guangrong
4d8b81abc4 KVM: introduce readonly memslot
In current code, if we map a readonly memory space from host to guest
and the page is not currently mapped in the host, we will get a fault
pfn and async is not allowed, then the vm will crash

We introduce readonly memory region to map ROM/ROMD to the guest, read access
is happy for readonly memslot, write access on readonly memslot will cause
KVM_EXIT_MMIO exit

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-22 15:09:03 +03:00
Xiao Guangrong
ca3a490c7d KVM: introduce KVM_HVA_ERR_BAD
Then, remove bad_hva and inline kvm_is_error_hva

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-22 15:08:59 +03:00
Xiao Guangrong
12ce13fea9 KVM: use 'writable' as a hint to map writable pfn
In current code, we always map writable pfn for the read fault, in order
to support readonly memslot, we map writable pfn only if 'writable'
is not NULL

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-22 15:08:55 +03:00
Xiao Guangrong
2fc843117d KVM: reorganize hva_to_pfn
We do too many things in hva_to_pfn, this patch reorganize the code,
let it be better readable

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-22 15:08:54 +03:00
Xiao Guangrong
86ab8cffb4 KVM: introduce gfn_to_hva_read/kvm_read_hva/kvm_read_hva_atomic
This set of functions is only used to read data from host space, in the
later patch, we will only get a readonly hva in gfn_to_hva_read, and
the function name is a good hint to let gfn_to_hva_read to pair with
kvm_read_hva()/kvm_read_hva_atomic()

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-22 15:08:53 +03:00
Xiao Guangrong
037d92dc5d KVM: introduce gfn_to_pfn_memslot_atomic
It can instead of hva_to_pfn_atomic

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-22 15:08:52 +03:00
Xiao Guangrong
a50d64d659 KVM: fix missing check for memslot flags
Check flags when memslot is registered from userspace as Avi's suggestion

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-22 15:08:50 +03:00
Xiao Guangrong
32cad84f44 KVM: do not release the error page
After commit a2766325cf, the error page is replaced by the
error code, it need not be released anymore

[ The patch has been compiling tested for powerpc ]

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-06 16:04:58 +03:00
Xiao Guangrong
cb9aaa30b1 KVM: do not release the error pfn
After commit a2766325cf, the error pfn is replaced by the
error code, it need not be released anymore

[ The patch has been compiling tested for powerpc ]

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-06 16:04:57 +03:00
Xiao Guangrong
6cede2e679 KVM: introduce KVM_ERR_PTR_BAD_PAGE
It is used to eliminate the overload of function call and cleanup
the code

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-06 16:04:55 +03:00
Xiao Guangrong
83f09228d0 KVM: inline is_*_pfn functions
These functions are exported and can not inline, move them
to kvm_host.h to eliminate the overload of function call

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-06 16:04:53 +03:00
Xiao Guangrong
950e95097b KVM: introduce KVM_PFN_ERR_BAD
Then, remove get_bad_pfn

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-06 16:04:52 +03:00
Xiao Guangrong
e6c1502b3f KVM: introduce KVM_PFN_ERR_HWPOISON
Then, get_hwpoison_pfn and is_hwpoison_pfn can be removed

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-06 16:04:52 +03:00
Xiao Guangrong
6c8ee57be9 KVM: introduce KVM_PFN_ERR_FAULT
After that, the exported and un-inline function, get_fault_pfn,
can be removed

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-06 16:04:50 +03:00
Takuya Yoshikawa
d89cc617b9 KVM: Push rmap into kvm_arch_memory_slot
Two reasons:
 - x86 can integrate rmap and rmap_pde and remove heuristics in
   __gfn_to_rmap().
 - Some architectures do not need rmap.

Since rmap is one of the most memory consuming stuff in KVM, ppc'd
better restrict the allocation to Book3S HV.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-06 12:47:30 +03:00
Christoffer Dall
23d43cf998 KVM: Move KVM_IRQ_LINE to arch-generic code
Handle KVM_IRQ_LINE and KVM_IRQ_LINE_STATUS in the generic
kvm_vm_ioctl() function and call into kvm_vm_ioctl_irq_line().

This is even more relevant when KVM/ARM also uses this ioctl.

Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-07-26 12:23:25 +03:00
Xiao Guangrong
a2766325cf KVM: remove dummy pages
Currently, kvm allocates some pages and use them as error indicators,
it wastes memory and is not good for scalability

Base on Avi's suggestion, we use the error codes instead of these pages
to indicate the error conditions

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-07-26 11:55:34 +03:00