The ARM architecture only saves the exit class to the HSR (ESR_EL2 for
arm64) on synchronous exceptions, not on asynchronous exceptions like an
IRQ. However, we only report the exception class on kvm_exit, which is
confusing because an IRQ looks like it exited at some PC with the same
reason as the previous exit. Add a lookup table for the exception index
and prepend the kvm_exit tracepoint text with the exception type to
clarify this situation.
Also resolve the exception class (EC) to a human-friendly text version
so the trace output becomes immediately usable for debugging this code.
Cc: Wei Huang <wei@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
We introduce kvm_arm_halt_guest and resume functions. They
will be used for IRQ forward state change.
Halt is synchronous and prevents the guest from being re-entered.
We use the same mechanism put in place for PSCI former pause,
now renamed power_off. A new flag is introduced in arch vcpu state,
pause, only meant to be used by those functions.
Signed-off-by: Eric Auger <eric.auger@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
In case a vcpu off PSCI call is called just after we executed the
vcpu_sleep check, we can enter the guest although power_off
is set. Let's check the power_off state in the critical section,
just before entering the guest.
Signed-off-by: Eric Auger <eric.auger@linaro.org>
Reported-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
kvm_arch_vcpu_runnable now also checks whether the power_off
flag is set.
Signed-off-by: Eric Auger <eric.auger@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
The kvm_vcpu_arch pause field is renamed into power_off to prepare
for the introduction of a new pause field. Also vcpu_pause is renamed
into vcpu_sleep since we will sleep until both power_off and pause are
false.
Signed-off-by: Eric Auger <eric.auger@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
The arch timer currently uses edge-triggered semantics in the sense that
the line is never sampled by the vgic and lowering the line from the
timer to the vgic doesn't have any effect on the pending state of
virtual interrupts in the vgic. This means that we do not support a
guest with the otherwise valid behavior of (1) disable interrupts (2)
enable the timer (3) disable the timer (4) enable interrupts. Such a
guest would validly not expect to see any interrupts on real hardware,
but will see interrupts on KVM.
This patch fixes this shortcoming through the following series of
changes.
First, we change the flow of the timer/vgic sync/flush operations. Now
the timer is always flushed/synced before the vgic, because the vgic
samples the state of the timer output. This has the implication that we
move the timer operations in to non-preempible sections, but that is
fine after the previous commit getting rid of hrtimer schedules on every
entry/exit.
Second, we change the internal behavior of the timer, letting the timer
keep track of its previous output state, and only lower/raise the line
to the vgic when the state changes. Note that in theory this could have
been accomplished more simply by signalling the vgic every time the
state *potentially* changed, but we don't want to be hitting the vgic
more often than necessary.
Third, we get rid of the use of the map->active field in the vgic and
instead simply set the interrupt as active on the physical distributor
whenever the input to the GIC is asserted and conversely clear the
physical active state when the input to the GIC is deasserted.
Fourth, and finally, we now initialize the timer PPIs (and all the other
unused PPIs for now), to be level-triggered, and modify the sync code to
sample the line state on HW sync and re-inject a new interrupt if it is
still pending at that time.
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
We currently schedule a soft timer every time we exit the guest if the
timer did not expire while running the guest. This is really not
necessary, because the only work we do in the timer work function is to
kick the vcpu.
Kicking the vcpu does two things:
(1) If the vpcu thread is on a waitqueue, make it runnable and remove it
from the waitqueue.
(2) If the vcpu is running on a different physical CPU from the one
doing the kick, it sends a reschedule IPI.
The second case cannot happen, because the soft timer is only ever
scheduled when the vcpu is not running. The first case is only relevant
when the vcpu thread is on a waitqueue, which is only the case when the
vcpu thread has called kvm_vcpu_block().
Therefore, we only need to make sure a timer is scheduled for
kvm_vcpu_block(), which we do by encapsulating all calls to
kvm_vcpu_block() with kvm_timer_{un}schedule calls.
Additionally, we only schedule a soft timer if the timer is enabled and
unmasked, since it is useless otherwise.
Note that theoretically userspace can use the SET_ONE_REG interface to
change registers that should cause the timer to fire, even if the vcpu
is blocked without a scheduled timer, but this case was not supported
before this patch and we leave it for future work for now.
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Jump to correct label and free kvm_host_cpu_state
Reviewed-by: Wei Huang <wei@redhat.com>
Signed-off-by: Pavel Fedin <p.fedin@samsung.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Until b26e5fdac4 ("arm/arm64: KVM: introduce per-VM ops"),
kvm_vgic_map_resources() used to include a check on irqchip_in_kernel(),
and vgic_v2_map_resources() still has it.
But now vm_ops are not initialized until we call kvm_vgic_create().
Therefore kvm_vgic_map_resources() can being called without a VGIC,
and we die because vm_ops.map_resources is NULL.
Fixing this restores QEMU's kernel-irqchip=off option to a working state,
allowing to use GIC emulation in userspace.
Fixes: b26e5fdac4 ("arm/arm64: KVM: introduce per-VM ops")
Cc: stable@vger.kernel.org
Signed-off-by: Pavel Fedin <p.fedin@samsung.com>
[maz: reworked commit message]
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
In order to be able to feed physical interrupts to a guest, we need
to be able to establish the virtual-physical mapping between the two
worlds.
The mappings are kept in a set of RCU lists, indexed by virtual interrupts.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
As we're about to introduce some serious GIC-poking to the vgic code,
it is important to make sure that we're going to poke the part of
the GIC that belongs to the CPU we're about to run on (otherwise,
we'd end up with some unexpected interrupts firing)...
Introducing a non-preemptible section in kvm_arch_vcpu_ioctl_run
prevents the problem from occuring.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
As we now inject the timer interrupt when we're about to enter
the guest, it makes a lot more sense to make sure this happens
before the vgic code queues the pending interrupts.
Otherwise, we get the interrupt on the following exit, which is
not great for latency (and leads to all kind of bizarre issues
when using with active interrupts at the HW level).
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
This introduces a level of indirection for the debug registers. Instead
of using the sys_regs[] directly we store registers in a structure in
the vcpu. The new kvm_arm_reset_debug_ptr() sets the debug ptr to the
guest context.
Because we no longer give the sys_regs offset for the sys_reg_desc->reg
field, but instead the index into a debug-specific struct we need to
add a number of additional trap functions for each register. Also as the
generic generic user-space access code no longer works we have
introduced a new pair of function pointers to the sys_reg_desc structure
to override the generic code when needed.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
This is a precursor for later patches which will need to do more to
setup debug state before entering the hyp.S switch code. The existing
functionality for setting mdcr_el2 has been moved out of hyp.S and now
uses the value kept in vcpu->arch.mdcr_el2.
As the assembler used to previously mask and preserve MDCR_EL2.HPMN I've
had to add a mechanism to save the value of mdcr_el2 as a per-cpu
variable during the initialisation code. The kernel never sets this
number so we are assuming the bootcode has set up the correct value
here.
This also moves the conditional setting of the TDA bit from the hyp code
into the C code which is currently used for the lazy debug register
context switch code.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
This commit adds a stub function to support the KVM_SET_GUEST_DEBUG
ioctl. Any unsupported flag will return -EINVAL. For now, only
KVM_GUESTDBG_ENABLE is supported, although it won't have any effects.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Until now we have been calling kvm_guest_exit after re-enabling
interrupts when we come back from the guest, but this has the
unfortunate effect that CPU time accounting done in the context of timer
interrupts occurring while the guest is running doesn't properly notice
that the time since the last tick was spent in the guest.
Inspired by the comment in the x86 code, move the kvm_guest_exit() call
below the local_irq_enable() call and change __kvm_guest_exit() to
kvm_guest_exit(), because we are now calling this function with
interrupts enabled. We have to now explicitly disable preemption and
not enable preemption before we've called kvm_guest_exit(), since
otherwise we could be preempted and everything happening before we
eventually get scheduled again would be accounted for as guest time.
At the same time, move the trace_kvm_exit() call outside of the atomic
section, since there is no reason for us to do that with interrupts
disabled.
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
We already check KVM_CAP_IRQFD in generic once enable CONFIG_HAVE_KVM_IRQFD,
kvm_vm_ioctl_check_extension_generic()
|
+ switch (arg) {
+ ...
+ #ifdef CONFIG_HAVE_KVM_IRQFD
+ case KVM_CAP_IRQFD:
+ #endif
+ ...
+ return 1;
+ ...
+ }
|
+ kvm_vm_ioctl_check_extension()
So its not necessary to check this in arch again, and also fix one typo,
s/emlation/emulation.
Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Use __kvm_guest_{enter|exit} instead of kvm_guest_{enter|exit}
where interrupts are disabled.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When userland injects a SPI via the KVM_IRQ_LINE ioctl we currently
only check it against a fixed limit, which historically is set
to 127. With the new dynamic IRQ allocation the effective limit may
actually be smaller (64).
So when now a malicious or buggy userland injects a SPI in that
range, we spill over on our VGIC bitmaps and bytemaps memory.
I could trigger a host kernel NULL pointer dereference with current
mainline by injecting some bogus IRQ number from a hacked kvmtool:
-----------------
....
DEBUG: kvm_vgic_inject_irq(kvm, cpu=0, irq=114, level=1)
DEBUG: vgic_update_irq_pending(kvm, cpu=0, irq=114, level=1)
DEBUG: IRQ #114 still in the game, writing to bytemap now...
Unable to handle kernel NULL pointer dereference at virtual address 00000000
pgd = ffffffc07652e000
[00000000] *pgd=00000000f658b003, *pud=00000000f658b003, *pmd=0000000000000000
Internal error: Oops: 96000006 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 1053 Comm: lkvm-msi-irqinj Not tainted 4.0.0-rc7+ #3027
Hardware name: FVP Base (DT)
task: ffffffc0774e9680 ti: ffffffc0765a8000 task.ti: ffffffc0765a8000
PC is at kvm_vgic_inject_irq+0x234/0x310
LR is at kvm_vgic_inject_irq+0x30c/0x310
pc : [<ffffffc0000ae0a8>] lr : [<ffffffc0000ae180>] pstate: 80000145
.....
So this patch fixes this by checking the SPI number against the
actual limit. Also we remove the former legacy hard limit of
127 in the ioctl code.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
CC: <stable@vger.kernel.org> # 4.0, 3.19, 3.18
[maz: wrap KVM_ARM_IRQ_GIC_MAX with #ifndef __KERNEL__,
as suggested by Christopher Covington]
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
As the infrastructure for eventfd has now been merged, report the
ioeventfd capability as being supported.
Signed-off-by: Nikolay Nikolaev <n.nikolaev@virtualopensystems.com>
[maz: grouped the case entry with the others, fixed commit log]
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
When a VCPU is no longer running, we currently check to see if it has a
timer scheduled in the future, and if it does, we schedule a host
hrtimer to notify is in case the timer expires while the VCPU is still
not running. When the hrtimer fires, we mask the guest's timer and
inject the timer IRQ (still relying on the guest unmasking the time when
it receives the IRQ).
This is all good and fine, but when migration a VM (checkpoint/restore)
this introduces a race. It is unlikely, but possible, for the following
sequence of events to happen:
1. Userspace stops the VM
2. Hrtimer for VCPU is scheduled
3. Userspace checkpoints the VGIC state (no pending timer interrupts)
4. The hrtimer fires, schedules work in a workqueue
5. Workqueue function runs, masks the timer and injects timer interrupt
6. Userspace checkpoints the timer state (timer masked)
At restore time, you end up with a masked timer without any timer
interrupts and your guest halts never receiving timer interrupts.
Fix this by only kicking the VCPU in the workqueue function, and sample
the expired state of the timer when entering the guest again and inject
the interrupt and mask the timer only then.
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
To cleanly restore an SMP VM we need to ensure that the current pause
state of each vcpu is correctly recorded. Things could get confused if
the CPU starts running after migration restore completes when it was
paused before it state was captured.
We use the existing KVM_GET/SET_MP_STATE ioctl to do this. The arm/arm64
interface is a lot simpler as the only valid states are
KVM_MP_STATE_RUNNABLE and KVM_MP_STATE_STOPPED.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
This patch enables irqfd on arm/arm64.
Both irqfd and resamplefd are supported. Injection is implemented
in vgic.c without routing.
This patch enables CONFIG_HAVE_KVM_EVENTFD and CONFIG_HAVE_KVM_IRQFD.
KVM_CAP_IRQFD is now advertised. KVM_CAP_IRQFD_RESAMPLE capability
automatically is advertised as soon as CONFIG_HAVE_KVM_IRQFD is set.
Irqfd injection is restricted to SPI. The rationale behind not
supporting PPI irqfd injection is that any device using a PPI would
be a private-to-the-CPU device (timer for instance), so its state
would have to be context-switched along with the VCPU and would
require in-kernel wiring anyhow. It is not a relevant use case for
irqfds.
Signed-off-by: Eric Auger <eric.auger@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
On arm/arm64 the VGIC is dynamically instantiated and it is useful
to expose its state, especially for irqfd setup.
This patch defines __KVM_HAVE_ARCH_INTC_INITIALIZED and
implements kvm_arch_intc_initialized.
Signed-off-by: Eric Auger <eric.auger@linaro.org>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
We can definitely decide at run-time whether to use the GIC and timers
or not, and the extra code and data structures that we allocate space
for is really negligable with this config option, so I don't think it's
worth the extra complexity of always having to define stub static
inlines. The !CONFIG_KVM_ARM_VGIC/TIMER case is pretty much an untested
code path anyway, so we're better off just getting rid of it.
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
IS_ENABLED gives compile-time checking and keeps the code clearer.
The one exception is inside kvm_vm_ioctl_check_extension, where
the established idiom is to wrap the case labels with an #ifdef.
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This patch extends trace_kvm_exit() to include KVM exit reasons
(i.e. EC of HSR). The tracing function then dumps both exit reason
and PC of vCPU, shown as the following. Tracing tools can use this
new exit_reason field to better understand the behavior of guest VMs.
886.301252: kvm_exit: HSR_EC: 0x0024, PC: 0xfffffe0000506b28
Signed-off-by: Wei Huang <wei@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Common: Optional support for adding a small amount of polling on each HLT
instruction executed in the guest (or equivalent for other architectures).
This can improve latency up to 50% on some scenarios (e.g. O_DSYNC writes
or TCP_RR netperf tests). This also has to be enabled manually for now,
but the plan is to auto-tune this in the future.
ARM/ARM64: the highlights are support for GICv3 emulation and dirty page
tracking
s390: several optimizations and bugfixes. Also a first: a feature
exposed by KVM (UUID and long guest name in /proc/sysinfo) before
it is available in IBM's hypervisor! :)
MIPS: Bugfixes.
x86: Support for PML (page modification logging, a new feature in
Broadwell Xeons that speeds up dirty page tracking), nested virtualization
improvements (nested APICv---a nice optimization), usual round of emulation
fixes. There is also a new option to reduce latency of the TSC deadline
timer in the guest; this needs to be tuned manually.
Some commits are common between this pull and Catalin's; I see you
have already included his tree.
ARM has other conflicts where functions are added in the same place
by 3.19-rc and 3.20 patches. These are not large though, and entirely
within KVM.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM update from Paolo Bonzini:
"Fairly small update, but there are some interesting new features.
Common:
Optional support for adding a small amount of polling on each HLT
instruction executed in the guest (or equivalent for other
architectures). This can improve latency up to 50% on some
scenarios (e.g. O_DSYNC writes or TCP_RR netperf tests). This
also has to be enabled manually for now, but the plan is to
auto-tune this in the future.
ARM/ARM64:
The highlights are support for GICv3 emulation and dirty page
tracking
s390:
Several optimizations and bugfixes. Also a first: a feature
exposed by KVM (UUID and long guest name in /proc/sysinfo) before
it is available in IBM's hypervisor! :)
MIPS:
Bugfixes.
x86:
Support for PML (page modification logging, a new feature in
Broadwell Xeons that speeds up dirty page tracking), nested
virtualization improvements (nested APICv---a nice optimization),
usual round of emulation fixes.
There is also a new option to reduce latency of the TSC deadline
timer in the guest; this needs to be tuned manually.
Some commits are common between this pull and Catalin's; I see you
have already included his tree.
Powerpc:
Nothing yet.
The KVM/PPC changes will come in through the PPC maintainers,
because I haven't received them yet and I might end up being
offline for some part of next week"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (130 commits)
KVM: ia64: drop kvm.h from installed user headers
KVM: x86: fix build with !CONFIG_SMP
KVM: x86: emulate: correct page fault error code for NoWrite instructions
KVM: Disable compat ioctl for s390
KVM: s390: add cpu model support
KVM: s390: use facilities and cpu_id per KVM
KVM: s390/CPACF: Choose crypto control block format
s390/kernel: Update /proc/sysinfo file with Extended Name and UUID
KVM: s390: reenable LPP facility
KVM: s390: floating irqs: fix user triggerable endless loop
kvm: add halt_poll_ns module parameter
kvm: remove KVM_MMIO_SIZE
KVM: MIPS: Don't leak FPU/DSP to guest
KVM: MIPS: Disable HTW while in guest
KVM: nVMX: Enable nested posted interrupt processing
KVM: nVMX: Enable nested virtual interrupt delivery
KVM: nVMX: Enable nested apic register virtualization
KVM: nVMX: Make nested control MSRs per-cpu
KVM: nVMX: Enable nested virtualize x2apic mode
KVM: nVMX: Prepare for using hardware MSR bitmap
...
Trying to emulate the behaviour of set/way cache ops is fairly
pointless, as there are too many ways we can end-up missing stuff.
Also, there is some system caches out there that simply ignore
set/way operations.
So instead of trying to implement them, let's convert it to VA ops,
and use them as a way to re-enable the trapping of VM ops. That way,
we can detect the point when the MMU/caches are turned off, and do
a full VM flush (which is what the guest was trying to do anyway).
This allows a 32bit zImage to boot on the APM thingy, and will
probably help bootloaders in general.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
1. Generic
- sparse warning (make function static)
- optimize locking
- bugfixes for interrupt injection
- fix MVPG addressing modes
2. hrtimer/wakeup fun
A recent change can cause KVM hangs if adjtime is used in the host.
The hrtimer might wake up too early or too late. Too early is fatal
as vcpu_block will see that the wakeup condition is not met and
sleep again. This CPU might never wake up again.
This series addresses this problem. adjclock slowing down the host
clock will result in too late wakeups. This will require more work.
In addition to that we also change the hrtimer from REALTIME to
MONOTONIC to avoid similar problems with timedatectl set-time.
3. sigp rework
We will move all "slow" sigps to QEMU (protected with a capability that
can be enabled) to avoid several races between concurrent SIGP orders.
4. Optimize the shadow page table
Provide an interface to announce the maximum guest size. The kernel
will use that to make the pagetable 2,3,4 (or theoretically) 5 levels.
5. Provide an interface to set the guest TOD
We now use two vm attributes instead of two oneregs, as oneregs are
vcpu ioctl and we don't want to call them from other threads.
6. Protected key functions
The real HMC allows to enable/disable protected key CPACF functions.
Lets provide an implementation + an interface for QEMU to activate
this the protected key instructions.
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Merge tag 'kvm-s390-next-20150122' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into kvm-next
KVM: s390: fixes and features for kvm/next (3.20)
1. Generic
- sparse warning (make function static)
- optimize locking
- bugfixes for interrupt injection
- fix MVPG addressing modes
2. hrtimer/wakeup fun
A recent change can cause KVM hangs if adjtime is used in the host.
The hrtimer might wake up too early or too late. Too early is fatal
as vcpu_block will see that the wakeup condition is not met and
sleep again. This CPU might never wake up again.
This series addresses this problem. adjclock slowing down the host
clock will result in too late wakeups. This will require more work.
In addition to that we also change the hrtimer from REALTIME to
MONOTONIC to avoid similar problems with timedatectl set-time.
3. sigp rework
We will move all "slow" sigps to QEMU (protected with a capability that
can be enabled) to avoid several races between concurrent SIGP orders.
4. Optimize the shadow page table
Provide an interface to announce the maximum guest size. The kernel
will use that to make the pagetable 2,3,4 (or theoretically) 5 levels.
5. Provide an interface to set the guest TOD
We now use two vm attributes instead of two oneregs, as oneregs are
vcpu ioctl and we don't want to call them from other threads.
6. Protected key functions
The real HMC allows to enable/disable protected key CPACF functions.
Lets provide an implementation + an interface for QEMU to activate
this the protected key instructions.
The return value of kvm_arch_vcpu_postcreate is not checked in its
caller. This is okay, because only x86 provides vcpu_postcreate right
now and it could only fail if vcpu_load failed. But that is not
possible during KVM_CREATE_VCPU (kvm_arch_vcpu_load is void, too), so
just get rid of the unchecked return value.
Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Currently the maximum number of vCPUs supported is a global value
limited by the used GIC model. GICv3 will lift this limit, but we
still need to observe it for guests using GICv2.
So the maximum number of vCPUs is per-VM value, depending on the
GIC model the guest uses.
Store and check the value in struct kvm_arch, but keep it down to
8 for now.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
With the introduction of a second emulated GIC model we need to let
userspace specify the GIC model to use for each VM. Pass the
userspace provided value down into the vGIC code and store it there
to differentiate later.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
The virtual MPIDR registers (containing topology information) for the
guest are currently mapped linearily to the vcpu_id. Improve this
mapping for arm64 by using three levels to not artificially limit the
number of vCPUs.
To help this, change and rename the kvm_vcpu_get_mpidr() function to
mask off the non-affinity bits in the MPIDR register.
Also add an accessor to later allow easier access to a vCPU with a
given MPIDR. Use this new accessor in the PSCI emulation.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
This patch enables ARMv8 ditry page logging support. Plugs ARMv8 into generic
layer through Kconfig symbol, and drops earlier ARM64 constraints to enable
logging at architecture layer.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Mario Smarduch <m.smarduch@samsung.com>
Add support to track dirty pages between user space KVM_GET_DIRTY_LOG ioctl
calls. We call kvm_get_dirty_log_protect() function to do most of the work.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Mario Smarduch <m.smarduch@samsung.com>
It is curently possible to run a VM with architected timers support
without creating an in-kernel VGIC, which will result in interrupts from
the virtual timer going nowhere.
To address this issue, move the architected timers initialization to the
time when we run a VCPU for the first time, and then only initialize
(and enable) the architected timers if we have a properly created and
initialized in-kernel VGIC.
When injecting interrupts from the virtual timer to the vgic, the
current setup should ensure that this never calls an on-demand init of
the VGIC, which is the only call path that could return an error from
kvm_vgic_inject_irq(), so capture the return value and raise a warning
if there's an error there.
We also change the kvm_timer_init() function from returning an int to be
a void function, since the function always succeeds.
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
When the vgic initializes its internal state it does so based on the
number of VCPUs available at the time. If we allow KVM to create more
VCPUs after the VGIC has been initialized, we are likely to error out in
unfortunate ways later, perform buffer overflows etc.
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
The vgic_initialized() macro currently returns the state of the
vgic->ready flag, which indicates if the vgic is ready to be used when
running a VM, not specifically if its internal state has been
initialized.
Rename the macro accordingly in preparation for a more nuanced
initialization flow.
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
VGIC initialization currently happens in three phases:
(1) kvm_vgic_create() (triggered by userspace GIC creation)
(2) vgic_init_maps() (triggered by userspace GIC register read/write
requests, or from kvm_vgic_init() if not already run)
(3) kvm_vgic_init() (triggered by first VM run)
We were doing initialization of some state to correspond with the
state of a freshly-reset GIC in kvm_vgic_init(); this is too late,
since it will overwrite changes made by userspace using the
register access APIs before the VM is run. Move this initialization
earlier, into the vgic_init_maps() phase.
This fixes a bug where QEMU could successfully restore a saved
VM state snapshot into a VM that had already been run, but could
not restore it "from cold" using the -loadvm command line option
(the symptoms being that the restored VM would run but interrupts
were ignored).
Finally rename vgic_init_maps to vgic_init and renamed kvm_vgic_init to
kvm_vgic_map_resources.
[ This patch is originally written by Peter Maydell, but I have
modified it somewhat heavily, renaming various bits and moving code
around. If something is broken, I am to be blamed. - Christoffer ]
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Introduce a new function to unmap user RAM regions in the stage2 page
tables. This is needed on reboot (or when the guest turns off the MMU)
to ensure we fault in pages again and make the dcache, RAM, and icache
coherent.
Using unmap_stage2_range for the whole guest physical range does not
work, because that unmaps IO regions (such as the GIC) which will not be
recreated or in the best case faulted in on a page-by-page basis.
Call this function on secondary and subsequent calls to the
KVM_ARM_VCPU_INIT ioctl so that a reset VCPU will detect the guest
Stage-1 MMU is off when faulting in pages and make the caches coherent.
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
It is not clear that this ioctl can be called multiple times for a given
vcpu. Userspace already does this, so clarify the ABI.
Also specify that userspace is expected to always make secondary and
subsequent calls to the ioctl with the same parameters for the VCPU as
the initial call (which userspace also already does).
Add code to check that userspace doesn't violate that ABI in the future,
and move the kvm_vcpu_set_target() function which is currently
duplicated between the 32-bit and 64-bit versions in guest.c to a common
static function in arm.c, shared between both architectures.
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
When userspace resets the vcpu using KVM_ARM_VCPU_INIT, we should also
reset the HCR, because we now modify the HCR dynamically to
enable/disable trapping of guest accesses to the VM registers.
This is crucial for reboot of VMs working since otherwise we will not be
doing the necessary cache maintenance operations when faulting in pages
with the guest MMU off.
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
The implementation of KVM_ARM_VCPU_INIT is currently not doing what
userspace expects, namely making sure that a vcpu which may have been
turned off using PSCI is returned to its initial state, which would be
powered on if userspace does not set the KVM_ARM_VCPU_POWER_OFF flag.
Implement the expected functionality and clarify the ABI.
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
If a VCPU was originally started with power off (typically to be brought
up by PSCI in SMP configurations), there is no need to clear the
POWER_OFF flag in the kernel, as this flag is only tested during the
init ioctl itself.
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
This patch adds the necessary support for all host kernel PGSIZE and
VA_SPACE configuration options for both EL2 and the Stage-2 page tables.
However, for 40bit and 42bit PARange systems, the architecture mandates
that VTCR_EL2.SL0 is maximum 1, resulting in fewer levels of stage-2
pagge tables than levels of host kernel page tables. At the same time,
systems with a PARange > 42bit, we limit the IPA range by always setting
VTCR_EL2.T0SZ to 24.
To solve the situation with different levels of page tables for Stage-2
translation than the host kernel page tables, we allocate a dummy PGD
with pointers to our actual inital level Stage-2 page table, in order
for us to reuse the kernel pgtable manipulation primitives. Reproducing
all these in KVM does not look pretty and unnecessarily complicates the
32-bit side.
Systems with a PARange < 40bits are not yet supported.
[ I have reworked this patch from its original form submitted by
Jungseok to take the architecture constraints into consideration.
There were too many changes from the original patch for me to
preserve the authorship. Thanks to Catalin Marinas for his help in
figuring out a good solution to this challenge. I have also fixed
various bugs and missing error code handling from the original
patch. - Christoffer ]
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Jungseok Lee <jungseoklee85@gmail.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
On some platforms with no power management capabilities, the hotplug
implementation is allowed to return from a smp_ops.cpu_die() call as a
function return. Upon a CPU onlining event, the KVM CPU notifier tries
to reinstall the hyp stub, which fails on platform where no reset took
place following a hotplug event, with the message:
CPU1: smp_ops.cpu_die() returned, trying to resuscitate
CPU1: Booted secondary processor
Kernel panic - not syncing: unexpected prefetch abort in Hyp mode at: 0x80409540
unexpected data abort in Hyp mode at: 0x80401fe8
unexpected HVC/SVC trap in Hyp mode at: 0x805c6170
since KVM code is trying to reinstall the stub on a system where it is
already configured.
To prevent this issue, this patch adds a check in the KVM hotplug
notifier that detects if the HYP stub really needs re-installing when a
CPU is onlined and skips the installation call if the stub is already in
place, which means that the CPU has not been reset.
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
The current aarch64 calculation for VTTBR_BADDR_MASK masks only 39 bits
and not all the bits in the PA range. This is clearly a bug that
manifests itself on systems that allocate memory in the higher address
space range.
[ Modified from Joel's original patch to be based on PHYS_MASK_SHIFT
instead of a hard-coded value and to move the alignment check of the
allocation to mmu.c. Also added a comment explaining why we hardcode
the IPA range and changed the stage-2 pgd allocation to be based on
the 40 bit IPA range instead of the maximum possible 48 bit PA range.
- Christoffer ]
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Joel Schopp <joel.schopp@amd.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
It is now quite easy to delay the allocation of the vgic tables
until we actually require it to be up and running (when the first
vcpu is kicking around, or someones tries to access the GIC registers).
This allow us to allocate memory for the exact number of CPUs we
have. As nobody configures the number of interrupts just yet,
use a fallback to VGIC_NR_IRQS_LEGACY.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
So far, all the VGIC data structures are statically defined by the
*maximum* number of vcpus and interrupts it supports. It means that
we always have to oversize it to cater for the worse case.
Start by changing the data structures to be dynamically sizeable,
and allocate them at runtime.
The sizes are still very static though.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
