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Commit Graph

298 Commits

Author SHA1 Message Date
Gleb Natapov
acb5451789 KVM: prevent spurious exit to userspace during task switch emulation.
If kvm_task_switch() fails code exits to userspace without specifying
exit reason, so the previous exit reason is reused by userspace. Fix
this by specifying exit reason correctly.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-05-17 12:17:55 +03:00
Jan Kiszka
e269fb2189 KVM: x86: Push potential exception error code on task switches
When a fault triggers a task switch, the error code, if existent, has to
be pushed on the new task's stack. Implement the missing bits.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-05-17 12:17:46 +03:00
Gleb Natapov
020df0794f KVM: move DR register access handling into generic code
Currently both SVM and VMX have their own DR handling code. Move it to
x86.c.

Acked-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-05-17 12:17:39 +03:00
Gleb Natapov
cf8f70bfe3 KVM: x86 emulator: fix in/out emulation.
in/out emulation is broken now. The breakage is different depending
on where IO device resides. If it is in userspace emulator reports
emulation failure since it incorrectly interprets kvm_emulate_pio()
return value. If IO device is in the kernel emulation of 'in' will do
nothing since kvm_emulate_pio() stores result directly into vcpu
registers, so emulator will overwrite result of emulation during
commit of shadowed register.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-05-17 12:16:25 +03:00
Gui Jianfeng
3129994458 KVM: VMX: change to use bool return values
Make use of bool as return values, and remove some useless
bool value converting. Thanks Avi to point this out.

Signed-off-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-05-17 12:15:51 +03:00
Wei Yongjun
ec68798c8f KVM: x86: Use native_store_idt() instead of kvm_get_idt()
This patch use generic linux function native_store_idt()
instead of kvm_get_idt(), and also removed the useless
function kvm_get_idt().

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-05-17 12:15:28 +03:00
Avi Kivity
5bfd8b5455 KVM: Move kvm_exit tracepoint rip reading inside tracepoint
Reading rip is expensive on vmx, so move it inside the tracepoint so we only
incur the cost if tracing is enabled.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-05-17 12:15:25 +03:00
Jan Kiszka
f8c5fae166 KVM: VMX: blocked-by-sti must not defer NMI injections
As the processor may not consider GUEST_INTR_STATE_STI as a reason for
blocking NMI, it could return immediately with EXIT_REASON_NMI_WINDOW
when we asked for it. But as we consider this state as NMI-blocking, we
can run into an endless loop.

Resolve this by allowing NMI injection if just GUEST_INTR_STATE_STI is
active (originally suggested by Gleb). Intel confirmed that this is
safe, the processor will never complain about NMI injection in this
state.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
KVM-Stable-Tag
Acked-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-05-13 01:31:37 -03:00
Gleb Natapov
2d49ec72d3 KVM: move segment_base() into vmx.c
segment_base() is used only by vmx so move it there.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-04-25 13:53:39 +03:00
Gleb Natapov
d6ab1ed446 KVM: Drop kvm_get_gdt() in favor of generic linux function
Linux now has native_store_gdt() to do the same. Use it instead of
kvm local version.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-04-25 13:53:32 +03:00
Jan Kiszka
48005f64d0 KVM: x86: Save&restore interrupt shadow mask
The interrupt shadow created by STI or MOV-SS-like operations is part of
the VCPU state and must be preserved across migration. Transfer it in
the spare padding field of kvm_vcpu_events.interrupt.

As a side effect we now have to make vmx_set_interrupt_shadow robust
against both shadow types being set. Give MOV SS a higher priority and
skip STI in that case to avoid that VMX throws a fault on next entry.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-04-25 12:38:28 +03:00
Gleb Natapov
89a27f4d0e KVM: use desc_ptr struct instead of kvm private descriptor_table
x86 arch defines desc_ptr for idt/gdt pointers, no need to define
another structure in kvm code.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-04-25 12:27:28 +03:00
Ingo Molnar
70bce3ba77 Merge branch 'linus' into perf/core
Merge reason: merge the latest fixes, update to latest -rc.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-23 11:10:30 +02:00
Avi Kivity
78ac8b47c5 KVM: VMX: Save/restore rflags.vm correctly in real mode
Currently we set eflags.vm unconditionally when entering real mode emulation
through virtual-8086 mode, and clear it unconditionally when we enter protected
mode.  The means that the following sequence

  KVM_SET_REGS  (rflags.vm=1)
  KVM_SET_SREGS (cr0.pe=1)

Ends up with rflags.vm clear due to KVM_SET_SREGS triggering enter_pmode().

Fix by shadowing rflags.vm (and rflags.iopl) correctly while in real mode:
reads and writes to those bits access a shadow register instead of the actual
register.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-04-20 12:59:31 +03:00
Zhang, Yanmin
ff9d07a0e7 KVM: Implement perf callbacks for guest sampling
Below patch implements the perf_guest_info_callbacks on kvm.

Signed-off-by: Zhang Yanmin <yanmin_zhang@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-04-19 12:36:50 +03:00
Tejun Heo
5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from  to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Jan Kiszka
c573cd2293 KVM: VMX: Update instruction length on intercepted BP
We intercept #BP while in guest debugging mode. As VM exits due to
intercepted exceptions do not necessarily come with valid
idt_vectoring, we have to update event_exit_inst_len explicitly in such
cases. At least in the absence of migration, this ensures that
re-injections of #BP will find and use the correct instruction length.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: stable@kernel.org (2.6.32, 2.6.33)
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-03-01 12:36:14 -03:00
Sheng Yang
a19a6d1131 KVM: VMX: Rename VMX_EPT_IGMT_BIT to VMX_EPT_IPAT_BIT
Following the new SDM. Now the bit is named "Ignore PAT memory type".

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-03-01 12:36:09 -03:00
Julia Lawall
c45b4fd416 KVM: VMX: Remove redundant test in vmx_set_efer()
msr was tested above, so the second test is not needed.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@r@
expression *x;
expression e;
identifier l;
@@

if (x == NULL || ...) {
    ... when forall
    return ...; }
... when != goto l;
    when != x = e
    when != &x
*x == NULL
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-03-01 12:36:07 -03:00
Avi Kivity
ebcbab4c03 KVM: VMX: Wire up .fpu_activate() callback
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-03-01 12:36:07 -03:00
Gui Jianfeng
6d3e435e70 KVM: VMX: Remove redundant check in vm_need_virtualize_apic_accesses()
flexpriority_enabled implies cpu_has_vmx_virtualize_apic_accesses() returning
true, so we don't need this check here.

Signed-off-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-03-01 12:36:06 -03:00
Avi Kivity
59200273c4 KVM: Trace failed msr reads and writes
Record failed msrs reads and writes, and the fact that they failed as well.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-03-01 12:36:06 -03:00
Avi Kivity
81231c698a KVM: VMX: Pass cr0.mp through to the guest when the fpu is active
When cr0.mp is clear, the guest doesn't expect a #NM in response to
a WAIT instruction.  Because we always keep cr0.mp set, it will get
a #NM, and potentially be confused.

Fix by keeping cr0.mp set only when the fpu is inactive, and passing
it through when inactive.

Reported-by: Lorenzo Martignoni <martignlo@gmail.com>
Analyzed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-03-01 12:36:06 -03:00
Avi Kivity
f6801dff23 KVM: Rename vcpu->shadow_efer to efer
None of the other registers have the shadow_ prefix.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-03-01 12:36:04 -03:00
Avi Kivity
3eeb3288bc KVM: Add a helper for checking if the guest is in protected mode
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-03-01 12:36:04 -03:00
Avi Kivity
6b52d18605 KVM: Activate fpu on clts
Assume that if the guest executes clts, it knows what it's doing, and load the
guest fpu to prevent an #NM exception.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-03-01 12:36:04 -03:00
Jan Kiszka
fd7373cce7 KVM: VMX: Clean up DR6 emulation
As we trap all debug register accesses, we do not need to switch real
DR6 at all. Clean up update_exception_bitmap at this chance, too.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-03-01 12:36:02 -03:00
Jan Kiszka
138ac8d88f KVM: VMX: Fix emulation of DR4 and DR5
Make sure DR4 and DR5 are aliased to DR6 and DR7, respectively, if
CR4.DE is not set.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-03-01 12:36:01 -03:00
Jan Kiszka
f248341529 KVM: VMX: Fix exceptions of mov to dr
Injecting GP without an error code is a bad idea (causes unhandled guest
exits). Moreover, we must not skip the instruction if we injected an
exception.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-03-01 12:36:01 -03:00
Sheng Yang
7062dcaa36 KVM: VMX: Remove emulation failure report
As Avi noted:

>There are two problems with the kernel failure report.  First, it
>doesn't report enough data - registers, surrounding instructions, etc.
>that are needed to explain what is going on.  Second, it can flood
>dmesg, which is a pretty bad thing to do.

So we remove the emulation failure report in handle_invalid_guest_state(),
and would inspected the guest using userspace tool in the future.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-03-01 12:36:01 -03:00
Avi Kivity
edcafe3c5a KVM: VMX: Give the guest ownership of cr0.ts when the fpu is active
If the guest fpu is loaded, there is nothing interesing about cr0.ts; let
the guest play with it as it will.  This makes context switches between fpu
intensive guest processes faster, as we won't trap the clts and cr0 write
instructions.

[marcelo: fix cr0 read shadow update on fpu deactivation; kills F8 install]

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-03-01 12:35:50 -03:00
Avi Kivity
02daab21d9 KVM: Lazify fpu activation and deactivation
Defer fpu deactivation as much as possible - if the guest fpu is loaded, keep
it loaded until the next heavyweight exit (where we are forced to unload it).
This reduces unnecessary exits.

We also defer fpu activation on clts; while clts signals the intent to use the
fpu, we can't be sure the guest will actually use it.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-03-01 12:35:50 -03:00
Avi Kivity
e8467fda83 KVM: VMX: Allow the guest to own some cr0 bits
We will use this later to give the guest ownership of cr0.ts.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-03-01 12:35:50 -03:00
Avi Kivity
4d4ec08745 KVM: Replace read accesses of vcpu->arch.cr0 by an accessor
Since we'd like to allow the guest to own a few bits of cr0 at times, we need
to know when we access those bits.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-03-01 12:35:50 -03:00
Avi Kivity
a1f83a74fe KVM: VMX: trace clts and lmsw instructions as cr accesses
clts writes cr0.ts; lmsw writes cr0[0:15] - record that in ftrace.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-03-01 12:35:50 -03:00
Sheng Yang
878403b788 KVM: VMX: Enable EPT 1GB page support
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-03-01 12:35:46 -03:00
Sheng Yang
17cc393596 KVM: x86: Rename gb_page_enable() to get_lpage_level() in kvm_x86_ops
Then the callback can provide the maximum supported large page level, which
is more flexible.

Also move the gb page support into x86_64 specific.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-03-01 12:35:46 -03:00
Avi Kivity
f4c9e87c83 KVM: Fill out ftrace exit reason strings
Some exit reasons missed their strings; fill out the table.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-03-01 12:35:45 -03:00
Marcelo Tosatti
79fac95ecf KVM: convert slots_lock to a mutex
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-03-01 12:35:45 -03:00
Marcelo Tosatti
f656ce0185 KVM: switch vcpu context to use SRCU
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-03-01 12:35:45 -03:00
Marcelo Tosatti
bc6678a33d KVM: introduce kvm->srcu and convert kvm_set_memory_region to SRCU update
Use two steps for memslot deletion: mark the slot invalid (which stops
instantiation of new shadow pages for that slot, but allows destruction),
then instantiate the new empty slot.

Also simplifies kvm_handle_hva locking.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-03-01 12:35:44 -03:00
Marcelo Tosatti
46a26bf557 KVM: modify memslots layout in struct kvm
Have a pointer to an allocated region inside struct kvm.

[alex: fix ppc book 3s]

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-03-01 12:35:43 -03:00
Sheng Yang
4e47c7a6d7 KVM: VMX: Add instruction rdtscp support for guest
Before enabling, execution of "rdtscp" in guest would result in #UD.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-03-01 12:35:40 -03:00
Sheng Yang
0e85188049 KVM: Add cpuid_update() callback to kvm_x86_ops
Sometime, we need to adjust some state in order to reflect guest CPUID
setting, e.g. if we don't expose rdtscp to guest, we won't want to enable
it on hardware. cpuid_update() is introduced for this purpose.

Also export kvm_find_cpuid_entry() for later use.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-03-01 12:35:40 -03:00
Sheng Yang
8a7e3f01e6 KVM: VMX: Remove redundant variable
It's no longer necessary.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-03-01 12:35:40 -03:00
Avi Kivity
bc23008b61 KVM: VMX: Fold ept_update_paging_mode_cr4() into its caller
ept_update_paging_mode_cr4() accesses vcpu->arch.cr4 directly, which usually
needs to be accessed via kvm_read_cr4().  In this case, we can't, since cr4
is in the process of being updated.  Instead of adding inane comments, fold
the function into its caller (vmx_set_cr4), so it can use the not-yet-committed
cr4 directly.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-03-01 12:35:40 -03:00
Avi Kivity
ce03e4f21a KVM: VMX: When using ept, allow the guest to own cr4.pge
We make no use of cr4.pge if ept is enabled, but the guest does (to flush
global mappings, as with vmap()), so give the guest ownership of this bit.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-03-01 12:35:39 -03:00
Avi Kivity
4c38609ac5 KVM: VMX: Make guest cr4 mask more conservative
Instead of specifying the bits which we want to trap on, specify the bits
which we allow the guest to change transparently.  This is safer wrt future
changes to cr4.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-03-01 12:35:39 -03:00
Avi Kivity
fc78f51938 KVM: Add accessor for reading cr4 (or some bits of cr4)
Some bits of cr4 can be owned by the guest on vmx, so when we read them,
we copy them to the vcpu structure.  In preparation for making the set of
guest-owned bits dynamic, use helpers to access these bits so we don't need
to know where the bit resides.

No changes to svm since all bits are host-owned there.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-03-01 12:35:39 -03:00
Avi Kivity
cdc0e24456 KVM: VMX: Move some cr[04] related constants to vmx.c
They have no place in common code.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-03-01 12:35:39 -03:00
Sheng Yang
59708670b6 KVM: VMX: Trap and invalid MWAIT/MONITOR instruction
We don't support these instructions, but guest can execute them even if the
feature('monitor') haven't been exposed in CPUID. So we would trap and inject
a #UD if guest try this way.

Cc: stable@kernel.org
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-03-01 12:35:39 -03:00
Avi Kivity
d5696725b2 KVM: VMX: Fix comparison of guest efer with stale host value
update_transition_efer() masks out some efer bits when deciding whether
to switch the msr during guest entry; for example, NX is emulated using the
mmu so we don't need to disable it, and LMA/LME are handled by the hardware.

However, with shared msrs, the comparison is made against a stale value;
at the time of the guest switch we may be running with another guest's efer.

Fix by deferring the mask/compare to the actual point of guest entry.

Noted by Marcelo.

Signed-off-by: Avi Kivity <avi@redhat.com>
2009-12-03 09:34:20 +02:00
Sheng Yang
046d87103a KVM: VMX: Disable unrestricted guest when EPT disabled
Otherwise would cause VMEntry failure when using ept=0 on unrestricted guest
supported processors.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2009-12-03 09:32:25 +02:00
Jan Kiszka
3cfc3092f4 KVM: x86: Add KVM_GET/SET_VCPU_EVENTS
This new IOCTL exports all yet user-invisible states related to
exceptions, interrupts, and NMIs. Together with appropriate user space
changes, this fixes sporadic problems of vmsave/restore, live migration
and system reset.

[avi: future-proof abi by adding a flags field]

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-12-03 09:32:25 +02:00
Avi Kivity
65ac726404 KVM: VMX: Report unexpected simultaneous exceptions as internal errors
These happen when we trap an exception when another exception is being
delivered; we only expect these with MCEs and page faults.  If something
unexpected happens, things probably went south and we're better off reporting
an internal error and freezing.

Signed-off-by: Avi Kivity <avi@redhat.com>
2009-12-03 09:32:24 +02:00
Avi Kivity
a9c7399d6c KVM: Allow internal errors reported to userspace to carry extra data
Usually userspace will freeze the guest so we can inspect it, but some
internal state is not available.  Add extra data to internal error
reporting so we can expose it to the debugger.  Extra data is specific
to the suberror.

Signed-off-by: Avi Kivity <avi@redhat.com>
2009-12-03 09:32:24 +02:00
Avi Kivity
92c0d90015 KVM: VMX: Remove vmx->msr_offset_efer
This variable is used to communicate between a caller and a callee; switch
to a function argument instead.

Signed-off-by: Avi Kivity <avi@redhat.com>
2009-12-03 09:32:23 +02:00
Marcelo Tosatti
7c93be44a4 KVM: VMX: move CR3/PDPTR update to vmx_set_cr3
GUEST_CR3 is updated via kvm_set_cr3 whenever CR3 is modified from
outside guest context. Similarly pdptrs are updated via load_pdptrs.

Let kvm_set_cr3 perform the update, removing it from the vcpu_run
fast path.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Acked-by: Acked-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-12-03 09:32:22 +02:00
Avi Kivity
26bb0981b3 KVM: VMX: Use shared msr infrastructure
Instead of reloading syscall MSRs on every preemption, use the new shared
msr infrastructure to reload them at the last possible minute (just before
exit to userspace).

Improves vcpu/idle/vcpu switches by about 2000 cycles (when EFER needs to be
reloaded as well).

[jan: fix slot index missing indirection]

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-12-03 09:32:22 +02:00
Avi Kivity
44ea2b1758 KVM: VMX: Move MSR_KERNEL_GS_BASE out of the vmx autoload msr area
Currently MSR_KERNEL_GS_BASE is saved and restored as part of the
guest/host msr reloading.  Since we wish to lazy-restore all the other
msrs, save and reload MSR_KERNEL_GS_BASE explicitly instead of using
the common code.

Signed-off-by: Avi Kivity <avi@redhat.com>
2009-12-03 09:32:21 +02:00
Eduardo Habkost
fa40052ca0 KVM: VMX: Use macros instead of hex value on cr0 initialization
This should have no effect, it is just to make the code clearer.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-12-03 09:32:21 +02:00
Marcelo Tosatti
9fb41ba896 KVM: VMX: fix handle_pause declaration
There's no kvm_run argument anymore.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2009-12-03 09:32:18 +02:00
Zhai, Edwin
4b8d54f972 KVM: VMX: Add support for Pause-Loop Exiting
New NHM processors will support Pause-Loop Exiting by adding 2 VM-execution
control fields:
PLE_Gap    - upper bound on the amount of time between two successive
             executions of PAUSE in a loop.
PLE_Window - upper bound on the amount of time a guest is allowed to execute in
             a PAUSE loop

If the time, between this execution of PAUSE and previous one, exceeds the
PLE_Gap, processor consider this PAUSE belongs to a new loop.
Otherwise, processor determins the the total execution time of this loop(since
1st PAUSE in this loop), and triggers a VM exit if total time exceeds the
PLE_Window.
* Refer SDM volume 3b section 21.6.13 & 22.1.3.

Pause-Loop Exiting can be used to detect Lock-Holder Preemption, where one VP
is sched-out after hold a spinlock, then other VPs for same lock are sched-in
to waste the CPU time.

Our tests indicate that most spinlocks are held for less than 212 cycles.
Performance tests show that with 2X LP over-commitment we can get +2% perf
improvement for kernel build(Even more perf gain with more LPs).

Signed-off-by: Zhai Edwin <edwin.zhai@intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2009-12-03 09:32:17 +02:00
Jan Kiszka
355be0b930 KVM: x86: Refactor guest debug IOCTL handling
Much of so far vendor-specific code for setting up guest debug can
actually be handled by the generic code. This also fixes a minor deficit
in the SVM part /wrt processing KVM_GUESTDBG_ENABLE.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-12-03 09:32:14 +02:00
Zachary Amsden
3230bb4707 KVM: Fix hotplug of CPUs
Both VMX and SVM require per-cpu memory allocation, which is done at module
init time, for only online cpus.

Backend was not allocating enough structure for all possible CPUs, so
new CPUs coming online could not be hardware enabled.

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2009-12-03 09:32:13 +02:00
Alexander Graf
10474ae894 KVM: Activate Virtualization On Demand
X86 CPUs need to have some magic happening to enable the virtualization
extensions on them. This magic can result in unpleasant results for
users, like blocking other VMMs from working (vmx) or using invalid TLB
entries (svm).

Currently KVM activates virtualization when the respective kernel module
is loaded. This blocks us from autoloading KVM modules without breaking
other VMMs.

To circumvent this problem at least a bit, this patch introduces on
demand activation of virtualization. This means, that instead
virtualization is enabled on creation of the first virtual machine
and disabled on destruction of the last one.

So using this, KVM can be easily autoloaded, while keeping other
hypervisors usable.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-12-03 09:32:10 +02:00
Mohammed Gamal
80ced186d1 KVM: VMX: Enhance invalid guest state emulation
- Change returned handle_invalid_guest_state() to return relevant exit codes
- Move triggering the emulation from vmx_vcpu_run() to vmx_handle_exit()
- Return to userspace instead of repeatedly trying to emulate instructions that have already failed

Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2009-12-03 09:32:09 +02:00
Avi Kivity
851ba6922a KVM: Don't pass kvm_run arguments
They're just copies of vcpu->run, which is readily accessible.

Signed-off-by: Avi Kivity <avi@redhat.com>
2009-12-03 09:32:06 +02:00
Marcelo Tosatti
eb5109e311 KVM: VMX: flush TLB with INVEPT on cpu migration
It is possible that stale EPTP-tagged mappings are used, if a
vcpu migrates to a different pcpu.

Set KVM_REQ_TLB_FLUSH in vmx_vcpu_load, when switching pcpus, which
will invalidate both VPID and EPT mappings on the next vm-entry.

Cc: stable@kernel.org
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2009-10-04 13:57:24 +02:00
Avi Kivity
0a79b00952 KVM: VMX: Check cpl before emulating debug register access
Debug registers may only be accessed from cpl 0.  Unfortunately, vmx will
code to emulate the instruction even though it was issued from guest
userspace, possibly leading to an unexpected trap later.

Cc: stable@kernel.org
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2009-09-10 18:11:10 +03:00
Gleb Natapov
542423b0dd KVM: VMX: call vmx_load_host_state() only if msr is cached
No need to call it before each kvm_(set|get)_msr_common()

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2009-09-10 18:11:07 +03:00
Avi Kivity
e8a48342e9 KVM: VMX: Conditionally reload debug register 6
Only reload debug register 6 if we're running with the guest's
debug registers.  Saves around 150 cycles from the guest lightweight
exit path.

dr6 contains a couple of bits that are updated on #DB, so intercept
that unconditionally and update those bits then.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2009-09-10 18:11:06 +03:00
Gleb Natapov
5fff7d270b KVM: VMX: Fix cr8 exiting control clobbering by EPT
Don't call adjust_vmx_controls() two times for the same control.
It restores options that were dropped earlier.  This loses us the cr8
exit control, which causes a massive performance regression Windows x64.

Cc: stable@kernel.org
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-09-10 10:46:57 +03:00
Sheng Yang
95eb84a758 KVM: VMX: Fix EPT with WP bit change during paging
QNX update WP bit when paging enabled, which is not covered yet. This one fix
QNX boot with EPT.

Cc: stable@kernel.org
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-09-10 10:46:53 +03:00
Avi Kivity
345dcaa8fd KVM: VMX: Adjust rflags if in real mode emulation
We set rflags.vm86 when virtualizing real mode to do through vm8086 mode;
so we need to take it out again when reading rflags.

Signed-off-by: Avi Kivity <avi@redhat.com>
2009-09-10 10:46:43 +03:00
Roel Kluin
3a34a8810b KVM: fix EFER read buffer overflow
Check whether index is within bounds before grabbing the element.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Cc: Avi Kivity <avi@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-09-10 08:33:21 +03:00
Avi Kivity
eab4b8aa34 KVM: VMX: Optimize vmx_get_cpl()
Instead of calling vmx_get_segment() (which reads a whole bunch of
vmcs fields), read only the cs selector which contains the cpl.

Signed-off-by: Avi Kivity <avi@redhat.com>
2009-09-10 08:33:21 +03:00
Joerg Roedel
344f414fa0 KVM: report 1GB page support to userspace
If userspace knows that the kernel part supports 1GB pages it can enable
the corresponding cpuid bit so that guests actually use GB pages.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-09-10 08:33:19 +03:00
Jan Kiszka
7f582ab6d8 KVM: VMX: Avoid to return ENOTSUPP to userland
Choose some allowed error values for the cases VMX returned ENOTSUPP so
far as these values could be returned by the KVM_RUN IOCTL.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2009-09-10 08:33:17 +03:00
Sheng Yang
b927a3cec0 KVM: VMX: Introduce KVM_SET_IDENTITY_MAP_ADDR ioctl
Now KVM allow guest to modify guest's physical address of EPT's identity mapping page.

(change from v1, discard unnecessary check, change ioctl to accept parameter
address rather than value)

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2009-09-10 08:33:16 +03:00
Marcelo Tosatti
229456fc34 KVM: convert custom marker based tracing to event traces
This allows use of the powerful ftrace infrastructure.

See Documentation/trace/ for usage information.

[avi, stephen: various build fixes]
[sheng: fix control register breakage]

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-09-10 08:32:59 +03:00
Avi Kivity
d3edefc003 KVM: VMX: Only reload guest cr2 if different from host cr2
cr2 changes only rarely, and writing it is expensive.  Avoid the costly cr2
writes by checking if it does not already hold the desired value.

Shaves 70 cycles off the vmexit latency.

Signed-off-by: Avi Kivity <avi@redhat.com>
2009-09-10 08:32:57 +03:00
Marcelo Tosatti
54dee9933e KVM: VMX: conditionally disable 2M pages
Disable usage of 2M pages if VMX_EPT_2MB_PAGE_BIT (bit 16) is clear
in MSR_IA32_VMX_EPT_VPID_CAP and EPT is enabled.

[avi: s/largepages_disabled/largepages_enabled/ to avoid negative logic]

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-09-10 08:32:56 +03:00
Marcelo Tosatti
68f89400bc KVM: VMX: EPT misconfiguration handler
Handler for EPT misconfiguration which checks for valid state
in the shadow pagetables, printing the spte on each level.

The separate WARN_ONs are useful for kerneloops.org.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-09-10 08:32:56 +03:00
Marcelo Tosatti
e799794e02 KVM: VMX: more MSR_IA32_VMX_EPT_VPID_CAP capability bits
Required for EPT misconfiguration handler.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-09-10 08:32:55 +03:00
Andre Przywara
71db602322 KVM: Move performance counter MSR access interception to generic x86 path
The performance counter MSRs are different for AMD and Intel CPUs and they
are chosen mainly by the CPUID vendor string. This patch catches writes to
all addresses (regardless of VMX/SVM path) and handles them in the generic
MSR handler routine. Writing a 0 into the event select register is something
we perfectly emulate ;-), so don't print out a warning to dmesg in this
case.
This fixes booting a 64bit Windows guest with an AMD CPUID on an Intel host.

Signed-off-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-09-10 08:32:54 +03:00
Gleb Natapov
c5af89b68a KVM: Introduce kvm_vcpu_is_bsp() function.
Use it instead of open code "vcpu_id zero is BSP" assumption.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-09-10 08:32:51 +03:00
Avi Kivity
7ffd92c53c KVM: VMX: Move rmode structure to vmx-specific code
rmode is only used in vmx, so move it to vmx.c

Signed-off-by: Avi Kivity <avi@redhat.com>
2009-09-10 08:32:50 +03:00
Nitin A Kamble
3a624e29c7 KVM: VMX: Support Unrestricted Guest feature
"Unrestricted Guest" feature is added in the VMX specification.
Intel Westmere and onwards processors will support this feature.

    It allows kvm guests to run real mode and unpaged mode
code natively in the VMX mode when EPT is turned on. With the
unrestricted guest there is no need to emulate the guest real mode code
in the vm86 container or in the emulator. Also the guest big real mode
code works like native.

  The attached patch enhances KVM to use the unrestricted guest feature
if available on the processor. It also adds a new kernel/module
parameter to disable the unrestricted guest feature at the boot time.

Signed-off-by: Nitin A Kamble <nitin.a.kamble@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-09-10 08:32:49 +03:00
Avi Kivity
596ae89565 KVM: VMX: Fix reporting of unhandled EPT violations
Instead of returning -ENOTSUPP, exit normally but indicate the hardware
exit reason.

Signed-off-by: Avi Kivity <avi@redhat.com>
2009-09-10 08:32:46 +03:00
Avi Kivity
6de4f3ada4 KVM: Cache pdptrs
Instead of reloading the pdptrs on every entry and exit (vmcs writes on vmx,
guest memory access on svm) extract them on demand.

Signed-off-by: Avi Kivity <avi@redhat.com>
2009-09-10 08:32:46 +03:00
Avi Kivity
8f5d549f02 KVM: VMX: Simplify pdptr and cr3 management
Instead of reading the PDPTRs from memory after every exit (which is slow
and wrong, as the PDPTRs are stored on the cpu), sync the PDPTRs from
memory to the VMCS before entry, and from the VMCS to memory after exit.
Do the same for cr3.

Signed-off-by: Avi Kivity <avi@redhat.com>
2009-09-10 08:32:46 +03:00
Avi Kivity
2d84e993a8 KVM: VMX: Avoid duplicate ept tlb flush when setting cr3
vmx_set_cr3() will call vmx_tlb_flush(), which will flush the ept context.
So there is no need to call ept_sync_context() explicitly.

Signed-off-by: Avi Kivity <avi@redhat.com>
2009-09-10 08:32:46 +03:00
Gleb Natapov
787ff73637 KVM: Drop interrupt shadow when single stepping should be done only on VMX
The problem exists only on VMX. Also currently we skip this step if
there is pending exception. The patch fixes this too.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-09-10 08:32:41 +03:00
Jaswinder Singh Rajput
af24a4e4ae KVM: Replace MSR_IA32_TIME_STAMP_COUNTER with MSR_IA32_TSC of msr-index.h
Use standard msr-index.h's MSR declaration.

MSR_IA32_TSC is better than MSR_IA32_TIME_STAMP_COUNTER as it also solves
80 column issue.

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-09-10 08:32:38 +03:00
Gleb Natapov
ae0bb3e011 KVM: VMX: Properly handle software interrupt re-injection in real mode
When reinjecting a software interrupt or exception, use the correct
instruction length provided by the hardware instead of a hardcoded 1.

Fixes problems running the suse 9.1 livecd boot loader.

Problem introduced by commit f0a3602c20 ("KVM: Move interrupt injection
logic to x86.c").

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-09-10 08:32:38 +03:00
Jan Kiszka
263799a361 KVM: VMX: Fix locking imbalance on emulation failure
We have to disable preemption and IRQs on every exit from
handle_invalid_guest_state, otherwise we generate at least a
preempt_disable imbalance.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-08-05 13:59:45 +03:00
Jan Kiszka
34f0c1ad27 KVM: VMX: Fix locking order in handle_invalid_guest_state
Release and re-acquire preemption and IRQ lock in the same order as
vcpu_enter_guest does.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-08-05 13:59:44 +03:00
Avi Kivity
e3c7cb6ad7 KVM: VMX: Handle vmx instruction vmexits
IF a guest tries to use vmx instructions, inject a #UD to let it know the
instruction is not implemented, rather than crashing.

This prevents guest userspace from crashing the guest kernel.

Cc: stable@kernel.org
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-06-28 14:10:31 +03:00
Mel Gorman
6484eb3e2a page allocator: do not check NUMA node ID when the caller knows the node is valid
Callers of alloc_pages_node() can optionally specify -1 as a node to mean
"allocate from the current node".  However, a number of the callers in
fast paths know for a fact their node is valid.  To avoid a comparison and
branch, this patch adds alloc_pages_exact_node() that only checks the nid
with VM_BUG_ON().  Callers that know their node is valid are then
converted.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Paul Mundt <lethal@linux-sh.org>	[for the SLOB NUMA bits]
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:32 -07:00