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Marc Zyngier
fd5fa1c8d0 KVM: arm64: selftests: vgic_irq: Remove LR-bound limitation
Good news: our GIC emulation is not completely broken, and we can
activate as many interrupts as we want.

Bump the test to cover all the SGIs, all the allowed PPIs, and
31 SPIs. Yes, 31, because we have 31 available priorities, and the
test is not happy with having two interrupts with the same priority.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-46-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:15 -08:00
Marc Zyngier
5053c2ab92 KVM: arm64: selftests: vgic_irq: Exclude timer-controlled interrupts
The PPI injection API is clear that you can't inject the timer PPIs
from userspace, since they are controlled by the timers themselves.

Add an exclusion list for this purpose.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-45-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:15 -08:00
Marc Zyngier
8b7888c511 KVM: arm64: selftests: vgic_irq: Change configuration before enabling interrupt
The architecture is pretty clear that changing the configuration of
an enable interrupt is not OK. It doesn't really matter here, but
doing the right thing is not more expensive.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-44-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:15 -08:00
Marc Zyngier
27392612c8 KVM: arm64: selftests: vgic_irq: Fix GUEST_ASSERT_IAR_EMPTY() helper
No, 0 is not a spurious INTID. Never been, never was.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-43-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:14 -08:00
Marc Zyngier
2366295c76 KVM: arm64: selftests: gic_v3: Disable Group-0 interrupts by default
Make sure G0 is disabled at the point of initialising the GIC.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-42-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:14 -08:00
Marc Zyngier
a1650de7c1 KVM: arm64: selftests: gic_v3: Add irq group setting helper
Being able to set the group of an interrupt is pretty useful.
Add such a helper.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-41-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:14 -08:00
Marc Zyngier
07bb1c5622 KVM: arm64: GICv2: Always trap GICV_DIR register
Since we can't decide to trap the DIR register on a per-vcpu basis,
always trap the second page of the GIC CPU interface. Yes, this is
costly. On the bright side, no sane SW should use EOImode==1 on
GICv2...

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-40-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:14 -08:00
Marc Zyngier
255de897e7 KVM: arm64: GICv2: Handle deactivation via GICV_DIR traps
Add the plumbing of GICv2 interrupt deactivation via GICV_DIR.
This requires adding a new device so that we can easily decode
the DIR address.

The deactivation itself is very similar to the GICv3 version.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-39-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:14 -08:00
Marc Zyngier
281c6c06e2 KVM: arm64: GICv2: Handle LR overflow when EOImode==0
Similarly to the GICv3 version, handle the EOIcount-driven deactivation
by walking the overflow list.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-38-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:14 -08:00
Marc Zyngier
78ffc28456 KVM: arm64: GICv3: Force exit to sync ICH_HCR_EL2.En
FEAT_NV2 is pretty terrible for anything that tries to enforce immediate
effects, and writing to ICH_HCR_EL2 in the hope to disable a maintenance
interrupt is vain. This only hits memory, and the guest hasn't cleared
anything -- the MI will fire.

For example, running the vgic_irq test under NV results in about 800
maintenance interrupts being actually handled by the L1 guest,
when none were expected.

As a cheap workaround, read back ICH_MISR_EL2 after writing 0 to
ICH_HCR_EL2. This is very cheap on real HW, and causes a trap to
the host in NV, giving it the opportunity to retire the pending MI.
With this, the above test runs to completion without any MI being
actually handled.

Yes, this is really poor...

Tested-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-37-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:14 -08:00
Marc Zyngier
6dd333c894 KVM: arm64: GICv3: nv: Plug L1 LR sync into deactivation primitive
Pretty much like the rest of the LR handling, deactivation of an
L2 interrupt gets reflected in the L1 LRs, and therefore must be
propagated into the L1 shadow state if the interrupt is HW-bound.

Instead of directly handling the active state (which looks a bit
off as it ignores locking and L1->L0 HW propagation), use the new
deactivation primitive to perform the deactivation and deal with
the required maintenance.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-36-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:14 -08:00
Marc Zyngier
eb33ffa2bd KVM: arm64: GICv3: nv: Resync LRs/VMCR/HCR early for better MI emulation
The current approach to nested GICv3 support is to not do anything
while L2 is running, wait a transition from L2 to L1 to resync
LRs, VMCR and HCR, and only then evaluate the state to decide
whether to generate a maintenance interrupt.

This doesn't provide a good quality of emulation, and it would be
far preferable to find out early that we need to perform a switch.

Move the LRs/VMCR and HCR resync into vgic_v3_sync_nested(), so
that we have most of the state available. As we turning the vgic
off at this stage to avoid a screaming host MI, add a new helper
vgic_v3_flush_nested() that switches the vgic on again. The MI can
then be directly injected as required.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-35-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:14 -08:00
Marc Zyngier
84792050e0 KVM: arm64: GICv3: Avoid broadcast kick on CPUs lacking TDIR
CPUs lacking TDIR always trap ICV_DIR_EL1, no matter what, since
we have ICH_HCR_EL2.TC set permanently. For these CPUs, it is
useless to use a broadcast kick on SPI injection, as the sole
purpose of this is to set TDIR.

We can therefore skip this on these CPUs, which are challenged
enough not to be burdened by extra IPIs. As a consequence,
permanently set the TDIR bit in the shadow state to notify the
fast-path emulation code of the exit reason.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-34-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:14 -08:00
Marc Zyngier
ca3c34da36 KVM: arm64: GICv3: Handle in-LR deactivation when possible
Even when we have either an LR overflow or SPIs in flight, it is
extremely likely that the interrupt being deactivated is still in
the LRs, and that going all the way back to the the generic trap
handling code is a waste of time.

Instead, try and deactivate in place when possible, and only if
this fails, perform a full exit.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-33-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:14 -08:00
Marc Zyngier
1c3b3cadcd KVM: arm64: GICv3: Add SPI tracking to handle asymmetric deactivation
SPIs are specially annpying, as they can be activated on a CPU and
deactivated on another. WHich means that when an SPI is in flight
anywhere, all CPUs need to have their TDIR trap bit set.

This translates into broadcasting an IPI across all CPUs to make sure
they set their trap bit, The number of in-flight SPIs is kept in
an atomic variable so that CPUs can turn the trap bit off as soon
as possible.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-32-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:14 -08:00
Marc Zyngier
70fd60bded KVM: arm64: GICv3: Set ICH_HCR_EL2.TDIR when interrupts overflow LR capacity
Now that we are ready to handle deactivation through ICV_DIR_EL1,
set the trap bit if we have active interrupts outside of the LRs.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-31-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:13 -08:00
Marc Zyngier
295b692165 KVM: arm64: GICv3: Add GICv2 SGI handling to deactivation primitive
The GICv2 SGIs require additional handling for deactivation, as they
are effectively multiple interrrupts muxed into one. Make sure we
check for the source CPU when deactivating.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-30-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:13 -08:00
Marc Zyngier
cd4f6ee99b KVM: arm64: GICv3: Handle deactivation via ICV_DIR_EL1 traps
Deactivation via ICV_DIR_EL1 is both relatively straightforward
(we have the interrupt that needs deactivation) and really awkward.

The main issue is that the interrupt may either be in an LR on
another CPU, or ourside of any LR.

In the former case, we process the deactivation is if ot was
a write to GICD_CACTIVERn, which is already implemented as a big
hammer IPI'ing all vcpus. In the latter case, we just perform
a normal deactivation, similar to what we do for EOImode==0.

Another annoying aspect is that we need to tell the CPU owning
the interrupt that its ap_list needs laudering. We use a brand new
vcpu request to that effect.

Note that this doesn't address deactivation via the GICV MMIO view,
which will be taken care of in a later change.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-29-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:13 -08:00
Marc Zyngier
3cfd59f81e KVM: arm64: GICv3: Handle LR overflow when EOImode==0
Now that we can identify interrupts that have not made it into the LRs,
it becomes relatively easy to use EOIcount to walk the overflow list.

What is a bit odd is that we compute a fake LR for the original
state of the interrupt, clear the active bit, and feed into the existing
logic for processing. In a way, this is what would have happened if
the interrupt was in an LR.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-28-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:13 -08:00
Marc Zyngier
a69e2d6f89 KVM: arm64: Use MI to detect groups being enabled/disabled
Add the maintenance interrupt to force an exit when the guest
enables/disables individual groups, so that we can resort the
ap_list accordingly.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-27-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:13 -08:00
Marc Zyngier
33c1f60b32 KVM: arm64: Move undeliverable interrupts to the end of ap_list
Interrupts in the ap_list that cannot be acted upon because they
are not enabled, or that their group is not enabled, shouldn't
make it into the LRs if we are space-constrained.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-26-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:13 -08:00
Marc Zyngier
05984ba67e KVM: arm64: Invert ap_list sorting to push active interrupts out
Having established that pending interrupts should have priority
to be moved into the LRs over the active interrupts, implement this
in the ap_list sorting.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-25-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:13 -08:00
Marc Zyngier
76b2eda65c KVM: arm64: Make vgic_target_oracle() globally available
Make the internal crystal ball global, so that implementation-specific
code can use it.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-24-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:13 -08:00
Marc Zyngier
f04b8a5a83 KVM: arm64: Turn kvm_vgic_vcpu_enable() into kvm_vgic_vcpu_reset()
Now that we always reconfigure the vgic HCR register on entry,
the "enable" part of kvm_vgic_vcpu_enable() is pretty useless.

Removing the enable bits from these functions makes it plain that
they are just about computing the reset state. Just rename the
functions accordingly.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-23-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:13 -08:00
Marc Zyngier
6780a75604 KVM: arm64: Revamp vgic maintenance interrupt configuration
We currently don't use the maintenance interrupt very much, apart
from EOI on level interrupts, and for LR underflow in limited cases.

However, as we are moving toward a setup where active interrupts
can live outside of the LRs, we need to use the MIs in a more
diverse set of cases.

Add a new helper that produces a digest of the ap_list, and use
that summary to set the various control bits as required.

This slightly changes the way v2 SGIs are handled, as they used to
count for more than one interrupt, but not anymore.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-22-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:13 -08:00
Marc Zyngier
cf72ee6371 KVM: arm64: Eagerly save VMCR on exit
We currently save/restore the VMCR register in a pretty lazy way
(on load/put, consistently with what we do with the APRs).

However, we are going to need the group-enable bits that are backed
by VMCR on each entry (so that we can avoid injecting interrupts for
disabled groups).

Move the synchronisation from put to sync, which results in some minor
churn in the nVHE hypercalls to simplify things.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-21-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:13 -08:00
Marc Zyngier
dd598fc113 KVM: arm64: Compute vgic state irrespective of the number of interrupts
As we are going to rely on the [G]ICH_HCR{,_EL2} register to be
programmed with MI information at all times, slightly de-optimise
the flush/sync code to always be called. This is rather lightweight
when no interrupts are in flight.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-20-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:12 -08:00
Marc Zyngier
0660bc4a2b KVM: arm64: GICv2: Extract LR computing primitive
Split vgic_v2_populate_lr() into two helpers, so that we have another
primitive that computes the LR from a vgic_irq, but doesn't update
anything in the shadow structure.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-19-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:12 -08:00
Marc Zyngier
3aa9a50c20 KVM: arm64: GICv2: Extract LR folding primitive
As we are going to need to handle deactivation for interrupts that
are not in the LRs, split vgic_v2_fold_lr_state() into a helper
that deals with a single interrupt, and the function that loops
over the used LRs.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-18-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:12 -08:00
Marc Zyngier
a00c88ac1f KVM: arm64: GICv2: Decouple GICH_HCR programming from LRs being loaded
Not programming GICH_HCR while no LRs are populated is a bit
of an issue, as we otherwise don't see any maintenance interrupt
when the guest interacts with the LRs.

Decouple the two and always program the control register, even when
we don't have to touch the LRs.

This is very similar to what we are already doing for GICv3.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-17-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:12 -08:00
Marc Zyngier
5ceb3dac80 KVM: arm64: GICv2: Preserve EOIcount on exit
EOIcount is how the virtual CPU interface signals that the guest
is deactivating interrupts outside of the LRs when EOImode==0.

We therefore need to preserve that information so that we can find
out what actually needs deactivating, just like we already do on
GICv3.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-16-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:12 -08:00
Marc Zyngier
1ae0448ca7 KVM: arm64: GICv3: Extract LR computing primitive
Split vgic_v3_populate_lr() into two, so that we have another
primitive that computes the LR from a vgic_irq, but doesn't
update anything in the shadow structure.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-15-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:12 -08:00
Marc Zyngier
438e47b697 KVM: arm64: GICv3: Extract LR folding primitive
As we are going to need to handle deactivation for interrupts that
are not in the LRs, split vgic_v3_fold_lr_state() into a helper
that deals with a single interrupt, and the function that loops
over the used LRs.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-14-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:12 -08:00
Marc Zyngier
00c6d0d4a8 KVM: arm64: GICv3: Decouple ICH_HCR_EL2 programming from LRs
Not programming ICH_HCR_EL2 while no LRs are populated is a bit
of an issue, as we otherwise don't see any maintenance interrupt
when the guest interacts with the LRs.

Decouple the two and always program the control register, even when
we don't have to touch the LRs.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-13-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:12 -08:00
Marc Zyngier
f4ded7b084 KVM: arm64: GICv3: Preserve EOIcount on exit
EOIcount is how the virtual CPU interface signals that the guest
is deactivating interrupts outside of the LRs when EOImode==0.

We therefore need to preserve that information so that we can find
out what actually needs deactivating.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-12-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:12 -08:00
Marc Zyngier
73c9726975 KVM: arm64: GICv3: Drop LPI active state when folding LRs
Despite LPIs not having an active state, *virtual* LPIs do have
one, which gets cleared on EOI. So far, so good.

However, this leads to a small problem: when an active LPI is not
in the LRs, that EOImode==0 and that the guest EOIs it, EOIcount
doesn't get bumped up. Which means that in these condition, the
LPI would stay active forever.

Clearly, we can't have that. So if we spot an active LPI, we drop
that state. It's pretty pointless anyway, and only serves as a way
to trip SW over.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-11-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:12 -08:00
Marc Zyngier
0dc433e79a KVM: arm64: Add LR overflow handling documentation
Add a bit of documentation describing how we are dealing with LR
overflow. This is mostly a braindump of how things are expected
to work. For now anyway.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-10-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:12 -08:00
Marc Zyngier
879a7fd4fd KVM: arm64: Add tracking of vgic_irq being present in a LR
We currently cannot identify whether an interrupt is queued into
a LR. It wasn't needed until now, but that's about to change.

Add yet another flag to track that state.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-9-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:12 -08:00
Marc Zyngier
a4413a7c31 KVM: arm64: Repack struct vgic_irq fields
struct vgic_irq has grown over the years, in a rather bad way.
Repack it using bitfields so that the individual flags, and move
things around a bit so that it a bit smaller.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-8-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:11 -08:00
Marc Zyngier
2a28810cbb KVM: arm64: GICv3: Detect and work around the lack of ICV_DIR_EL1 trapping
A long time ago, an unsuspecting architect forgot to add a trap
bit for ICV_DIR_EL1 in ICH_HCR_EL2. Which was unfortunate, but
what's a bit of spec between friends? Thankfully, this was fixed
in a later revision, and ARM "deprecates" the lack of trapping
ability.

Unfortuantely, a few (billion) CPUs went out with that defect,
anything ARMv8.0 from ARM, give or take. And on these CPUs,
you can't trap DIR on its own, full stop.

As the next best thing, we can trap everything in the common group,
which is a tad expensive, but hey ho, that's what you get. You can
otherwise recycle the HW in the neaby bin.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-7-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:11 -08:00
Marc Zyngier
567ebfedb5 KVM: arm64: vgic-v3: Fix GICv3 trapping in protected mode
As we are about to start trapping a bunch of extra things, augment
the pKVM trap description with all the registers trapped by ICH_HCR_EL2.TC,
making them legal instead of resulting in a UNDEF injection in the guest.

While we're at it, ensure that pKVM captures the vgic model so that it
can be checked by the emulation code.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-6-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:11 -08:00
Marc Zyngier
8d3dfab1d3 KVM: arm64: Turn vgic-v3 errata traps into a patched-in constant
The trap bits are currently only set to manage CPU errata. However,
we are about to make use of them for purposes beyond beating broken
CPUs into submission.

For this purpose, turn these errata-driven bits into a patched-in
constant that is merged with the KVM-driven value at the point of
programming the ICH_HCR_EL2 register, rather than being directly
stored with with the shadow value..

This allows the KVM code to distinguish between a trap being handled
for the purpose of an erratum workaround, or for KVM's own need.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-5-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:11 -08:00
Marc Zyngier
08f4f41c1e irqchip/apple-aic: Spit out ICH_MISR_EL2 value on spurious vGIC MI
It is all good and well to scream about spurious vGIC maintenance
interrupts. It would be even better to output the reason why, which
is already checked, but not printed out.

The unsuspecting kernel tinkerer thanks you.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-4-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:11 -08:00
Marc Zyngier
fa8f11e8e1 irqchip/gic: Expose CPU interface VA to KVM
Future changes will require KVM to be able to perform deactivations
by writing to the physical CPU interface. Add the corresponding
VA to the kvm_info structure, and let KVM stash it.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-3-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:11 -08:00
Marc Zyngier
8cb4ecec5e irqchip/gic: Add missing GICH_HCR control bits
The GICH_HCR description is missing a bunch of control bits that
control the maintenance interrupt. Add them.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-2-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:11 -08:00
Kiryl Shutsemau
7c9580f44f mm/filemap: fix logic around SIGBUS in filemap_map_pages()
Chris noticed that filemap_map_pages() calculates can_map_large only once
for the first page in the fault around range.  The value is not valid for
the following pages in the range and must be recalculated.

Instead of recalculating can_map_large on each iteration, pass down
file_end to filemap_map_folio_range() and let it make the decision on what
can be mapped.

Link: https://lkml.kernel.org/r/20251120161411.859078-1-kirill@shutemov.name
Fixes: 74207de2ba ("mm/memory: do not populate page table entries beyond i_size")h
Signed-off-by: Kiryl Shutsemau <kas@kernel.org>
Reported-by: Chris Mason <clm@meta.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Chris Mason <clm@meta.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: "Darrick J. Wong" <djwong@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-24 14:25:18 -08:00
Wei Yang
cff47b9e39 mm/huge_memory: fix NULL pointer deference when splitting folio
Commit c010d47f10 ("mm: thp: split huge page to any lower order pages")
introduced an early check on the folio's order via mapping->flags before
proceeding with the split work.

This check introduced a bug: for shmem folios in the swap cache and
truncated folios, the mapping pointer can be NULL.  Accessing
mapping->flags in this state leads directly to a NULL pointer dereference.

This commit fixes the issue by moving the check for mapping != NULL before
any attempt to access mapping->flags.

Link: https://lkml.kernel.org/r/20251119235302.24773-1-richard.weiyang@gmail.com
Fixes: c010d47f10 ("mm: thp: split huge page to any lower order pages")
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand (Red Hat) <david@kernel.org>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-24 14:25:17 -08:00
Pratyush Yadav
6c96c6bd2c MAINTAINERS: add test_kho to KHO's entry
Commit b753522bed ("kho: add test for kexec handover") introduced the
KHO test but missed adding it to KHO's MAINTAINERS entry.  Add it so the
KHO maintainers can get patches for its test.

Link: https://lkml.kernel.org/r/20251118182416.70660-1-pratyush@kernel.org
Fixes: b753522bed ("kho: add test for kexec handover")
Signed-off-by: Pratyush Yadav <pratyush@kernel.org>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Alexander Graf <graf@amazon.com>
Cc: Mike Rapoport <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-24 14:25:17 -08:00
Sam Protsenko
52ac3f5829 mailmap: add entry for Sam Protsenko
Use 'Sam Protsenko' as my name consistently in git-shortlog.  Also map my
old GlobalLogic email address to my current email to stay reachable.

Link: https://lkml.kernel.org/r/20251118033111.23382-1-semen.protsenko@linaro.org
Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-24 14:25:17 -08:00
Carlos Llamas
f0bb6dba3d selftests/mm: fix division-by-zero in uffd-unit-tests
Commit 4dfd4bba85 ("selftests/mm/uffd: refactor non-composite global
vars into struct") moved some of the operations previously implemented in
uffd_setup_environment() earlier in the main test loop.

The calculation of nr_pages, which involves a division by page_size, now
occurs before checking that default_huge_page_size() returns a non-zero
This leads to a division-by-zero error on systems with !CONFIG_HUGETLB.

Fix this by relocating the non-zero page_size check before the nr_pages
calculation, as it was originally implemented.

Link: https://lkml.kernel.org/r/20251113034623.3127012-1-cmllamas@google.com
Fixes: 4dfd4bba85 ("selftests/mm/uffd: refactor non-composite global vars into struct")
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Acked-by: David Hildenbrand (Red Hat) <david@kernel.org>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Ujwal Kundur <ujwal.kundur@gmail.com>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-24 14:25:17 -08:00