kvm_read_guest() will eventually look up in kvm_memslots(), which requires
either to hold the kvm->slots_lock or to be inside a kvm->srcu critical
section.
In contrast to x86 and s390 we don't take the SRCU lock on every guest
exit, so we have to do it individually for each kvm_read_guest() call.
Use the newly introduced wrapper for that.
Cc: Stable <stable@vger.kernel.org> # 4.12+
Reported-by: Jan Glauber <jan.glauber@caviumnetworks.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
kvm_read_guest() will eventually look up in kvm_memslots(), which requires
either to hold the kvm->slots_lock or to be inside a kvm->srcu critical
section.
In contrast to x86 and s390 we don't take the SRCU lock on every guest
exit, so we have to do it individually for each kvm_read_guest() call.
Provide a wrapper which does that and use that everywhere.
Note that ending the SRCU critical section before returning from the
kvm_read_guest() wrapper is safe, because the data has been *copied*, so
we don't need to rely on valid references to the memslot anymore.
Cc: Stable <stable@vger.kernel.org> # 4.8+
Reported-by: Jan Glauber <jan.glauber@caviumnetworks.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Apparently the development of update_affinity() overlapped with the
promotion of irq_lock to be _irqsave, so the patch didn't convert this
lock over. This will make lockdep complain.
Fix this by disabling IRQs around the lock.
Cc: stable@vger.kernel.org
Fixes: 08c9fd0421 ("KVM: arm/arm64: vITS: Add a helper to update the affinity of an LPI")
Reported-by: Jan Glauber <jan.glauber@caviumnetworks.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
As Jan reported [1], lockdep complains about the VGIC not being bullet
proof. This seems to be due to two issues:
- When commit 006df0f349 ("KVM: arm/arm64: Support calling
vgic_update_irq_pending from irq context") promoted irq_lock and
ap_list_lock to _irqsave, we forgot two instances of irq_lock.
lockdeps seems to pick those up.
- If a lock is _irqsave, any other locks we take inside them should be
_irqsafe as well. So the lpi_list_lock needs to be promoted also.
This fixes both issues by simply making the remaining instances of those
locks _irqsave.
One irq_lock is addressed in a separate patch, to simplify backporting.
[1] http://lists.infradead.org/pipermail/linux-arm-kernel/2018-May/575718.html
Cc: stable@vger.kernel.org
Fixes: 006df0f349 ("KVM: arm/arm64: Support calling vgic_update_irq_pending from irq context")
Reported-by: Jan Glauber <jan.glauber@caviumnetworks.com>
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
- Fix proxying of GICv2 CPU interface accesses
- Fix crash when switching to BE
- Track source vcpu git GICv2 SGIs
- Fix an outdated bit of documentation
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Merge tag 'kvmarm-fixes-for-4.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm
KVM/arm fixes for 4.17, take #2
- Fix proxying of GICv2 CPU interface accesses
- Fix crash when switching to BE
- Track source vcpu git GICv2 SGIs
- Fix an outdated bit of documentation
One comment still mentioned process_maintenance operations after
commit af0614991a ("KVM: arm/arm64: vgic: Get rid of unnecessary
process_maintenance operation")
Update the comment to point to vgic_fold_lr_state instead, which
is where maintenance interrupts are taken care of.
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
ARM:
- PSCI selection API, a leftover from 4.16 (for stable)
- Kick vcpu on active interrupt affinity change
- Plug a VMID allocation race on oversubscribed systems
- Silence debug messages
- Update Christoffer's email address (linaro -> arm)
x86:
- Expose userspace-relevant bits of a newly added feature
- Fix TLB flushing on VMX with VPID, but without EPT
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rMerge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM fixes from Radim Krčmář:
"ARM:
- PSCI selection API, a leftover from 4.16 (for stable)
- Kick vcpu on active interrupt affinity change
- Plug a VMID allocation race on oversubscribed systems
- Silence debug messages
- Update Christoffer's email address (linaro -> arm)
x86:
- Expose userspace-relevant bits of a newly added feature
- Fix TLB flushing on VMX with VPID, but without EPT"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
x86/headers/UAPI: Move DISABLE_EXITS KVM capability bits to the UAPI
kvm: apic: Flush TLB after APIC mode/address change if VPIDs are in use
arm/arm64: KVM: Add PSCI version selection API
KVM: arm/arm64: vgic: Kick new VCPU on interrupt migration
arm64: KVM: Demote SVE and LORegion warnings to debug only
MAINTAINERS: Update e-mail address for Christoffer Dall
KVM: arm/arm64: Close VMID generation race
Now that we make sure we don't inject multiple instances of the
same GICv2 SGI at the same time, we've made another bug more
obvious:
If we exit with an active SGI, we completely lose track of which
vcpu it came from. On the next entry, we restore it with 0 as a
source, and if that wasn't the right one, too bad. While this
doesn't seem to trouble GIC-400, the architectural model gets
offended and doesn't deactivate the interrupt on EOI.
Another connected issue is that we will happilly make pending
an interrupt from another vcpu, overriding the above zero with
something that is just as inconsistent. Don't do that.
The final issue is that we signal a maintenance interrupt when
no pending interrupts are present in the LR. Assuming we've fixed
the two issues above, we end-up in a situation where we keep
exiting as soon as we've reached the active state, and not be
able to inject the following pending.
The fix comes in 3 parts:
- GICv2 SGIs have their source vcpu saved if they are active on
exit, and restored on entry
- Multi-SGIs cannot go via the Pending+Active state, as this would
corrupt the source field
- Multi-SGIs are converted to using MI on EOI instead of NPIE
Fixes: 16ca6a607d ("KVM: arm/arm64: vgic: Don't populate multiple LRs with the same vintid")
Reported-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
It's possible for userspace to control n. Sanitize n when using it as an
array index.
Note that while it appears that n must be bound to the interval [0,3]
due to the way it is extracted from addr, we cannot guarantee that
compiler transformations (and/or future refactoring) will ensure this is
the case, and given this is a slow path it's better to always perform
the masking.
Found by smatch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: kvmarm@lists.cs.columbia.edu
Signed-off-by: Will Deacon <will.deacon@arm.com>
It's possible for userspace to control intid. Sanitize intid when using
it as an array index.
At the same time, sort the includes when adding <linux/nospec.h>.
Found by smatch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: kvmarm@lists.cs.columbia.edu
Signed-off-by: Will Deacon <will.deacon@arm.com>
When vgic_prune_ap_list() finds an interrupt that needs to be migrated
to a new VCPU, we should notify this VCPU of the pending interrupt,
since it requires immediate action.
Kick this VCPU once we have added the new IRQ to the list, but only
after dropping the locks.
Reported-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
vgic_copy_lpi_list() parses the LPI list and picks LPIs targeting
a given vcpu. We allocate the array containing the intids before taking
the lpi_list_lock, which means we can have an array size that is not
equal to the number of LPIs.
This is particularly obvious when looking at the path coming from
vgic_enable_lpis, which is not a command, and thus can run in parallel
with commands:
vcpu 0: vcpu 1:
vgic_enable_lpis
its_sync_lpi_pending_table
vgic_copy_lpi_list
intids = kmalloc_array(irq_count)
MAPI(lpi targeting vcpu 0)
list_for_each_entry(lpi_list_head)
intids[i++] = irq->intid;
At that stage, we will happily overrun the intids array. Boo. An easy
fix is is to break once the array is full. The MAPI command will update
the config anyway, and we won't miss a thing. We also make sure that
lpi_list_count is read exactly once, so that further updates of that
value will not affect the array bound check.
Cc: stable@vger.kernel.org
Fixes: ccb1d791ab ("KVM: arm64: vgic-its: Fix pending table sync")
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
It was recently reported that VFIO mediated devices, and anything
that VFIO exposes as level interrupts, do no strictly follow the
expected logic of such interrupts as it only lowers the input
line when the guest has EOId the interrupt at the GIC level, rather
than when it Acked the interrupt at the device level.
THe GIC's Active+Pending state is fundamentally incompatible with
this behaviour, as it prevents KVM from observing the EOI, and in
turn results in VFIO never dropping the line. This results in an
interrupt storm in the guest, which it really never expected.
As we cannot really change VFIO to follow the strict rules of level
signalling, let's forbid the A+P state altogether, as it is in the
end only an optimization. It ensures that we will transition via
an invalid state, which we can use to notify VFIO of the EOI.
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
Tested-by: Shunyong Yang <shunyong.yang@hxt-semitech.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
- Peace of mind locking fix in vgic_mmio_read_pending
- Allow hw-mapped interrupts to be reset when the VM resets
- Fix GICv2 multi-source SGI injection
- Fix MMIO synchronization for GICv2 on v3 emulation
- Remove excess verbosity on the console
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Merge tag 'kvm-arm-fixes-for-v4.16-2' into HEAD
Resolve conflicts with current mainline
As we're about to change the way we map devices at HYP, we need
to move away from kern_hyp_va on an IO address.
One way of achieving this is to store the VAs in kvm_vgic_global_state,
and use that directly from the HYP code. This requires a small change
to create_hyp_io_mappings so that it can also return a HYP VA.
We take this opportunity to nuke the vctrl_base field in the emulated
distributor, as it is not used anymore.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Both HYP io mappings call ioremap, followed by create_hyp_io_mappings.
Let's move the ioremap call into create_hyp_io_mappings itself, which
simplifies the code a bit and allows for further refactoring.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
We can finally get completely rid of any calls to the VGICv3
save/restore functions when the AP lists are empty on VHE systems. This
requires carefully factoring out trap configuration from saving and
restoring state, and carefully choosing what to do on the VHE and
non-VHE path.
One of the challenges is that we cannot save/restore the VMCR lazily
because we can only write the VMCR when ICC_SRE_EL1.SRE is cleared when
emulating a GICv2-on-GICv3, since otherwise all Group-0 interrupts end
up being delivered as FIQ.
To solve this problem, and still provide fast performance in the fast
path of exiting a VM when no interrupts are pending (which also
optimized the latency for actually delivering virtual interrupts coming
from physical interrupts), we orchestrate a dance of only doing the
activate/deactivate traps in vgic load/put for VHE systems (which can
have ICC_SRE_EL1.SRE cleared when running in the host), and doing the
configuration on every round-trip on non-VHE systems.
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
The APRs can only have bits set when the guest acknowledges an interrupt
in the LR and can only have a bit cleared when the guest EOIs an
interrupt in the LR. Therefore, if we have no LRs with any
pending/active interrupts, the APR cannot change value and there is no
need to clear it on every exit from the VM (hint: it will have already
been cleared when we exited the guest the last time with the LRs all
EOIed).
The only case we need to take care of is when we migrate the VCPU away
from a CPU or migrate a new VCPU onto a CPU, or when we return to
userspace to capture the state of the VCPU for migration. To make sure
this works, factor out the APR save/restore functionality into separate
functions called from the VCPU (and by extension VGIC) put/load hooks.
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Just like we can program the GICv2 hypervisor control interface directly
from the core vgic code, we can do the same for the GICv3 hypervisor
control interface on VHE systems.
We do this by simply calling the save/restore functions when we have VHE
and we can then get rid of the save/restore function calls from the VHE
world switch function.
One caveat is that we now write GICv3 system register state before the
potential early exit path in the run loop, and because we sync back
state in the early exit path, we have to ensure that we read a
consistent GIC state from the sync path, even though we have never
actually run the guest with the newly written GIC state. We solve this
by inserting an ISB in the early exit path.
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
We can program the GICv2 hypervisor control interface logic directly
from the core vgic code and can instead do the save/restore directly
from the flush/sync functions, which can lead to a number of future
optimizations.
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
There is really no need to store the vgic_elrsr on the VGIC data
structures as the only need we have for the elrsr is to figure out if an
LR is inactive when we save the VGIC state upon returning from the
guest. We can might as well store this in a temporary local variable.
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Moving the call to vcpu_load() in kvm_arch_vcpu_ioctl_run() to after
we've called kvm_vcpu_first_run_init() simplifies some of the vgic and
there is also no need to do vcpu_load() for things such as handling the
immediate_exit flag.
Reviewed-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
The vgic code is trying to be clever when injecting GICv2 SGIs,
and will happily populate LRs with the same interrupt number if
they come from multiple vcpus (after all, they are distinct
interrupt sources).
Unfortunately, this is against the letter of the architecture,
and the GICv2 architecture spec says "Each valid interrupt stored
in the List registers must have a unique VirtualID for that
virtual CPU interface.". GICv3 has similar (although slightly
ambiguous) restrictions.
This results in guests locking up when using GICv2-on-GICv3, for
example. The obvious fix is to stop trying so hard, and inject
a single vcpu per SGI per guest entry. After all, pending SGIs
with multiple source vcpus are pretty rare, and are mostly seen
in scenario where the physical CPUs are severely overcomitted.
But as we now only inject a single instance of a multi-source SGI per
vcpu entry, we may delay those interrupts for longer than strictly
necessary, and run the risk of injecting lower priority interrupts
in the meantime.
In order to address this, we adopt a three stage strategy:
- If we encounter a multi-source SGI in the AP list while computing
its depth, we force the list to be sorted
- When populating the LRs, we prevent the injection of any interrupt
of lower priority than that of the first multi-source SGI we've
injected.
- Finally, the injection of a multi-source SGI triggers the request
of a maintenance interrupt when there will be no pending interrupt
in the LRs (HCR_NPIE).
At the point where the last pending interrupt in the LRs switches
from Pending to Active, the maintenance interrupt will be delivered,
allowing us to add the remaining SGIs using the same process.
Cc: stable@vger.kernel.org
Fixes: 0919e84c0f ("KVM: arm/arm64: vgic-new: Add IRQ sync/flush framework")
Acked-by: Christoffer Dall <cdall@kernel.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
On my GICv3 system, the following is printed to the kernel log at boot:
kvm [1]: 8-bit VMID
kvm [1]: IDMAP page: d20e35000
kvm [1]: HYP VA range: 800000000000:ffffffffffff
kvm [1]: vgic-v2@2c020000
kvm [1]: GIC system register CPU interface enabled
kvm [1]: vgic interrupt IRQ1
kvm [1]: virtual timer IRQ4
kvm [1]: Hyp mode initialized successfully
The KVM IDMAP is a mapping of a statically allocated kernel structure,
and so printing its physical address leaks the physical placement of
the kernel when physical KASLR in effect. So change the kvm_info() to
kvm_debug() to remove it from the log output.
While at it, trim the output a bit more: IRQ numbers can be found in
/proc/interrupts, and the HYP VA and vgic-v2 lines are not highly
informational either.
Cc: <stable@vger.kernel.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Christoffer Dall <cdall@kernel.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
We currently don't allow resetting mapped IRQs from userspace, because
their state is controlled by the hardware. But we do need to reset the
state when the VM is reset, so we provide a function for the 'owner' of
the mapped interrupt to reset the interrupt state.
Currently only the timer uses mapped interrupts, so we call this
function from the timer reset logic.
Cc: stable@vger.kernel.org
Fixes: 4c60e360d6 ("KVM: arm/arm64: Provide a get_input_level for the arch timer")
Signed-off-by: Christoffer Dall <cdall@kernel.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Our irq_is_pending() helper function accesses multiple members of the
vgic_irq struct, so we need to hold the lock when calling it.
Add that requirement as a comment to the definition and take the lock
around the call in vgic_mmio_read_pending(), where we were missing it
before.
Fixes: 96b298000d ("KVM: arm/arm64: vgic-new: Add PENDING registers handlers")
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Commit 3d1ad640f8 ("KVM: arm/arm64: Fix GICv4 ITS initialization
issues") moved the vgic_supports_direct_msis() check in vgic_v4_init().
However when vgic_v4_init is called from vgic_its_create(), the has_its
field is not yet set. Hence vgic_supports_direct_msis returns false and
vgic_v4_init does nothing.
The gic/its init sequence is a bit messy, so let's be specific about the
prerequisite checks in the various call paths instead of relying on a
common wrapper.
Fixes: 3d1ad640f8 ("KVM: arm/arm64: Fix GICv4 ITS initialization issues")
Reported-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
For mapped IRQs (with the HW bit set in the LR) we have to follow some
rules of the architecture. One of these rules is that VM must not be
allowed to deactivate a virtual interrupt with the HW bit set unless the
physical interrupt is also active.
This works fine when injecting mapped interrupts, because we leave it up
to the injector to either set EOImode==1 or manually set the active
state of the physical interrupt.
However, the guest can set virtual interrupt to be pending or active by
writing to the virtual distributor, which could lead to deactivating a
virtual interrupt with the HW bit set without the physical interrupt
being active.
We could set the physical interrupt to active whenever we are about to
enter the VM with a HW interrupt either pending or active, but that
would be really slow, especially on GICv2. So we take the long way
around and do the hard work when needed, which is expected to be
extremely rare.
When the VM sets the pending state for a HW interrupt on the virtual
distributor we set the active state on the physical distributor, because
the virtual interrupt can become active and then the guest can
deactivate it.
When the VM clears the pending state we also clear it on the physical
side, because the injector might otherwise raise the interrupt. We also
clear the physical active state when the virtual interrupt is not
active, since otherwise a SPEND/CPEND sequence from the guest would
prevent signaling of future interrupts.
Changing the state of mapped interrupts from userspace is not supported,
and it's expected that userspace unmaps devices from VFIO before
attempting to set the interrupt state, because the interrupt state is
driven by hardware.
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
The GIC sometimes need to sample the physical line of a mapped
interrupt. As we know this to be notoriously slow, provide a callback
function for devices (such as the timer) which can do this much faster
than talking to the distributor, for example by comparing a few
in-memory values. Fall back to the good old method of poking the
physical GIC if no callback is provided.
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Level-triggered mapped IRQs are special because we only observe rising
edges as input to the VGIC, and we don't set the EOI flag and therefore
are not told when the level goes down, so that we can re-queue a new
interrupt when the level goes up.
One way to solve this problem is to side-step the logic of the VGIC and
special case the validation in the injection path, but it has the
unfortunate drawback of having to peak into the physical GIC state
whenever we want to know if the interrupt is pending on the virtual
distributor.
Instead, we can maintain the current semantics of a level triggered
interrupt by sort of treating it as an edge-triggered interrupt,
following from the fact that we only observe an asserting edge. This
requires us to be a bit careful when populating the LRs and when folding
the state back in though:
* We lower the line level when populating the LR, so that when
subsequently observing an asserting edge, the VGIC will do the right
thing.
* If the guest never acked the interrupt while running (for example if
it had masked interrupts at the CPU level while running), we have
to preserve the pending state of the LR and move it back to the
line_level field of the struct irq when folding LR state.
If the guest never acked the interrupt while running, but changed the
device state and lowered the line (again with interrupts masked) then
we need to observe this change in the line_level.
Both of the above situations are solved by sampling the physical line
and set the line level when folding the LR back.
* Finally, if the guest never acked the interrupt while running and
sampling the line reveals that the device state has changed and the
line has been lowered, we must clear the physical active state, since
we will otherwise never be told when the interrupt becomes asserted
again.
This has the added benefit of making the timer optimization patches
(https://lists.cs.columbia.edu/pipermail/kvmarm/2017-July/026343.html) a
bit simpler, because the timer code doesn't have to clear the active
state on the sync anymore. It also potentially improves the performance
of the timer implementation because the GIC knows the state or the LR
and only needs to clear the
active state when the pending bit in the LR is still set, where the
timer has to always clear it when returning from running the guest with
an injected timer interrupt.
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
We are about to distinguish between userspace accesses and mmio traps
for a number of the mmio handlers. When the requester vcpu is NULL, it
means we are handling a userspace access.
Factor out the functionality to get the request vcpu into its own
function, mostly so we have a common place to document the semantics of
the return value.
Also take the chance to move the functionality outside of holding a
spinlock and instead explicitly disable and enable preemption. This
supports PREEMPT_RT kernels as well.
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Fix ptr_ret.cocci warnings:
virt/kvm/arm/vgic/vgic-its.c:971:1-3: WARNING: PTR_ERR_OR_ZERO can be used
Use PTR_ERR_OR_ZERO rather than if(IS_ERR(...)) + PTR_ERR
Generated by: scripts/coccinelle/api/ptr_ret.cocci
Signed-off-by: Vasyl Gomonovych <gomonovych@gmail.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
vgic_set_owner acquires the irq lock without disabling interrupts,
resulting in a lockdep splat (an interrupt could fire and result
in the same lock being taken if the same virtual irq is to be
injected).
In practice, it is almost impossible to trigger this bug, but
better safe than sorry. Convert the lock acquisition to a
spin_lock_irqsave() and keep lockdep happy.
Reported-by: James Morse <james.morse@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Before performing an unmap, let's check that what we have was
really mapped the first place.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
We miss a test against NULL after allocation.
Fixes: 6d03a68f80 ("KVM: arm64: vgic-its: Turn device_id validation into generic ID validation")
Cc: stable@vger.kernel.org # 4.8
Reported-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
The current pending table parsing code assumes that we keep the
previous read of the pending bits, but keep that variable in
the current block, making sure it is discarded on each loop.
We end-up using whatever is on the stack. Who knows, it might
just be the right thing...
Fixes: 33d3bc9556 ("KVM: arm64: vgic-its: Read initial LPI pending table")
Cc: stable@vger.kernel.org # 4.8
Reported-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
The current pending table parsing code assumes that we keep the
previous read of the pending bits, but keep that variable in
the current block, making sure it is discarded on each loop.
We end-up using whatever is on the stack. Who knows, it might
just be the right thing...
Fixes: 280771252c ("KVM: arm64: vgic-v3: KVM_DEV_ARM_VGIC_SAVE_PENDING_TABLES")
Cc: stable@vger.kernel.org # 4.12
Reported-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Using the size of the structure we're allocating is a good idea
and avoids any surprise... In this case, we're happilly confusing
kvm_kernel_irq_routing_entry and kvm_irq_routing_entry...
Fixes: 95b110ab9a ("KVM: arm/arm64: Enable irqchip routing")
Cc: stable@vger.kernel.org # 4.8
Reported-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Commit f39d16cbab ("KVM: arm/arm64: Guard kvm_vgic_map_is_active against
!vgic_initialized") introduced a check whether the VGIC has been
initialized before accessing the spinlock and the VGIC data structure.
However the vgic_get_irq() call in the variable declaration sneaked
through the net, so lets make sure that this also gets called only after
we actually allocated the arrays this function accesses.
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
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Merge tag 'kvm-arm-gicv4-for-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
GICv4 Support for KVM/ARM for v4.15
Common:
- Python 3 support in kvm_stat
- Accounting of slabs to kmemcg
ARM:
- Optimized arch timer handling for KVM/ARM
- Improvements to the VGIC ITS code and introduction of an ITS reset
ioctl
- Unification of the 32-bit fault injection logic
- More exact external abort matching logic
PPC:
- Support for running hashed page table (HPT) MMU mode on a host that
is using the radix MMU mode; single threaded mode on POWER 9 is
added as a pre-requisite
- Resolution of merge conflicts with the last second 4.14 HPT fixes
- Fixes and cleanups
s390:
- Some initial preparation patches for exitless interrupts and crypto
- New capability for AIS migration
- Fixes
x86:
- Improved emulation of LAPIC timer mode changes, MCi_STATUS MSRs, and
after-reset state
- Refined dependencies for VMX features
- Fixes for nested SMI injection
- A lot of cleanups
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Merge tag 'kvm-4.15-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM updates from Radim Krčmář:
"First batch of KVM changes for 4.15
Common:
- Python 3 support in kvm_stat
- Accounting of slabs to kmemcg
ARM:
- Optimized arch timer handling for KVM/ARM
- Improvements to the VGIC ITS code and introduction of an ITS reset
ioctl
- Unification of the 32-bit fault injection logic
- More exact external abort matching logic
PPC:
- Support for running hashed page table (HPT) MMU mode on a host that
is using the radix MMU mode; single threaded mode on POWER 9 is
added as a pre-requisite
- Resolution of merge conflicts with the last second 4.14 HPT fixes
- Fixes and cleanups
s390:
- Some initial preparation patches for exitless interrupts and crypto
- New capability for AIS migration
- Fixes
x86:
- Improved emulation of LAPIC timer mode changes, MCi_STATUS MSRs,
and after-reset state
- Refined dependencies for VMX features
- Fixes for nested SMI injection
- A lot of cleanups"
* tag 'kvm-4.15-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (89 commits)
KVM: s390: provide a capability for AIS state migration
KVM: s390: clear_io_irq() requests are not expected for adapter interrupts
KVM: s390: abstract conversion between isc and enum irq_types
KVM: s390: vsie: use common code functions for pinning
KVM: s390: SIE considerations for AP Queue virtualization
KVM: s390: document memory ordering for kvm_s390_vcpu_wakeup
KVM: PPC: Book3S HV: Cosmetic post-merge cleanups
KVM: arm/arm64: fix the incompatible matching for external abort
KVM: arm/arm64: Unify 32bit fault injection
KVM: arm/arm64: vgic-its: Implement KVM_DEV_ARM_ITS_CTRL_RESET
KVM: arm/arm64: Document KVM_DEV_ARM_ITS_CTRL_RESET
KVM: arm/arm64: vgic-its: Free caches when GITS_BASER Valid bit is cleared
KVM: arm/arm64: vgic-its: New helper functions to free the caches
KVM: arm/arm64: vgic-its: Remove kvm_its_unmap_device
arm/arm64: KVM: Load the timer state when enabling the timer
KVM: arm/arm64: Rework kvm_timer_should_fire
KVM: arm/arm64: Get rid of kvm_timer_flush_hwstate
KVM: arm/arm64: Avoid phys timer emulation in vcpu entry/exit
KVM: arm/arm64: Move phys_timer_emulate function
KVM: arm/arm64: Use kvm_arm_timer_set/get_reg for guest register traps
...
Since VLPIs are injected directly by the hardware there's no need to
mark these as pending in software and queue them on the AP list.
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
We should only try to initialize GICv4 data structures on a GICv4
capable system. Move the vgic_supports_direct_msis() check inito
vgic_v4_init() so that any KVM VGIC initialization path does not fail
on non-GICv4 systems.
Also be slightly more strict in the checking of the return value in
vgic_its_create, and only error out on negative return values from the
vgic_v4_init() function. This is important because the kvm device code
only treats negative values as errors and only cleans up in this case.
Errornously treating a positive return value as an error from the
vgic_v4_init() function can lead to NULL pointer dereferences, as has
recently been observed.
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Yet another braindump so I can free some cells...
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
All it takes is the has_v4 flag to be set in gic_kvm_info
as well as "kvm-arm.vgic_v4_enable=1" being passed on the
command line for GICv4 to be enabled in KVM.
Acked-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
We so far allocate the doorbell interrupts without taking any
special measure regarding the affinity of these interrupts. We
simply move them around as required when the vcpu gets scheduled
on a different CPU.
But that's counting without userspace (and the evil irqbalance) that
can try and move the VPE interrupt around, causing the ITS code
to emit VMOVP commands and remap the doorbell to another redistributor.
Worse, this can happen while the vcpu is running, causing all kind
of trouble if the VPE is already resident, and we end-up in UNPRED
territory.
So let's take a definitive action and prevent userspace from messing
with us. This is just a matter of adding IRQ_NO_BALANCING to the
set of flags we already have, letting the kernel in sole control
of the affinity.
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
The GICv4 architecture doesn't make it easy for save/restore to
work, as it doesn't give any guarantee that the pending state
is written into the pending table.
So let's not take any chance, and let's return an error if
we encounter any LPI that has the HW bit set. In order for
userspace to distinguish this error from other failure modes,
use -EACCES as an error code.
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
The redistributor needs to be told which vPE is about to be run,
and tells us whether there is any pending VLPI on exit.
Let's add the scheduling calls to the vgic flush/sync functions,
allowing the VLPIs to be delivered to the guest.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
The doorbell interrupt is only useful if the vcpu is blocked on WFI.
In all other cases, recieving a doorbell interrupt is just a waste
of cycles.
So let's only enable the doorbell if a vcpu is getting blocked,
and disable it when it is unblocked. This is very similar to
what we're doing for the background timer.
Reviewed-by: Christoffer Dall <cdall@linaro.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Andre Przywara