Commit Graph

1445600 Commits

Author SHA1 Message Date
Sebastian Ene
b4d961351a firmware: arm_ffa: Fix Endpoint Memory Access Descriptor offset calculation
Use the descriptor's `ep_mem_offset` to calculate the start of the endpoint
memory access array and to comply with the FF-A spec instead of defaulting
to `sizeof(struct ffa_mem_region)`.
This requires moving `ffa_mem_region_additional_setup()` earlier in the setup
flow.
Also, add sanity checks to ensure the calculated descriptor offsets do not
exceed `max_fragsize`.

Fixes: 113580530e ("firmware: arm_ffa: Update memory descriptor to support v1.1 format")
Reviewed-by: Sudeep Holla <sudeep.holla@kernel.org>
Signed-off-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Sebastian Ene <sebastianene@google.com>
Link: https://patch.msgid.link/20260702103848.1647249-3-sebastianene@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-07-07 15:04:07 +01:00
Mostafa Saleh
3383ffb7ef firmware: arm_ffa: Fix out-of-bound writes in ffa_setup_and_transmit()
Sashiko (locally) reports multiple out-of-bound issues in
ffa_setup_and_transmit:
1) Writing ep_mem_access->reserved can write out of bounds for FFA
   versions < 1.2 as ffa_emad_size_get() returns 16 bytes in that case
   while reserved has an offset of 24.
   Instead of zeroing fields, memset the struct to zero first based on
   the FFA version.

2) Make sure there is enough size to write constituents.

While at it, convert the only sizeof() in the driver that uses a
type instead of variable.

Reviewed-by: Sudeep Holla <sudeep.holla@kernel.org>
Fixes: 111a833dc5 ("firmware: arm_ffa: Set reserved/MBZ fields to zero in the memory descriptors")
Signed-off-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Sebastian Ene <sebastianene@google.com>
Link: https://patch.msgid.link/20260702103848.1647249-2-sebastianene@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-07-07 15:04:07 +01:00
Sebastian Ene
2bd3c6c702 KVM: arm64: Zero out the stack initialized data in the FFA handler
Don't leak hypervisor stack data when using the FFA_VERSION call.
When the compiler doesn't support -ftrivial-auto-var-init=zero option
we need to zero out the stack initialized variable before returning data
to the host caller.

Closes:
https://lore.kernel.org/all/20260616160016.C62C81F000E9@smtp.kernel.org/

Reported-by: Sashiko AI <sashiko-bot@kernel.org>
Fixes: c9c012625e ("KVM: arm64: Trap FFA_VERSION host call in pKVM")
Reviewed-by: Vincent Donnefort <vdonnefort@google.com>
Link: https://lore.kernel.org/all/20260616160016.C62C81F000E9@smtp.kernel.org/
Signed-off-by: Sebastian Ene <sebastianene@google.com>
Link: https://patch.msgid.link/20260702103848.1647249-7-sebastianene@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-07-07 11:25:50 +01:00
Mostafa Saleh
6a7a181f69 KVM: arm64: Ensure FFA ranges are page aligned
Harden the check for the constituent memory region page alignment
to prevent over-sharing when the negotiated FFA_PAGE_SIZE size is
smaller than the system PAGE_SIZE.
At the moment we only check that the size of the range is page
aligned, and truncate the address to the page boundary which can
annotate more memory than needed as being used by the FF-A.

Fixes: 4360900017 ("KVM: arm64: Handle FFA_MEM_SHARE calls from the host")
Signed-off-by: Mostafa Saleh <smostafa@google.com>
Reviewed-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Sebastian Ene <sebastianene@google.com>
Link: https://patch.msgid.link/20260702103848.1647249-6-sebastianene@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-07-07 11:25:50 +01:00
Sebastian Ene
a6b49d27c1 KVM: arm64: Validate the offset to the mem access descriptor
Prevent the pKVM hypervisor from making assumptions that the
endpoint memory access descriptor (EMAD) comes right after the
FF-A memory region header.
Prior to FF-A version 1.1 the header of the memory region
didn't contain an offset to the endpoint memory access descriptor.
The layout of a memory transaction looks like this from 1.1 onward:
Type | Field name | Offset
[ Header | ffa_mem_region  | 0
  EMAD 1 | ffa_mem_region_attributes) | ffa_mem_region.ep_mem_offset
]
Verify that the offset to the first endpoint memory access descriptor
is within the mailbox buffer bounds.

Also, fix one hardcoded sizeof(struct ffa_mem_region_attributes) that
should be replaced ffa_emad_size_get() for compatibility with FFA v1.0.

Fixes: 42fb33dde4 ("KVM: arm64: Use FF-A 1.1 with pKVM")
Signed-off-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Sebastian Ene <sebastianene@google.com>
Reviewed-by: Vincent Donnefort <vdonnefort@google.com>
Link: https://patch.msgid.link/20260702103848.1647249-5-sebastianene@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-07-07 11:25:50 +01:00
Mostafa Saleh
8c6db30d79 KVM: arm64: Fix bounds checking in do_ffa_mem_reclaim()
Sashiko (locally) reports out of bound write possiblity if SPMD
returns an invalid data.

While SPMD is considered trusted, pKVM does some basic checks,
for offset to be less than or equal len.

However, that is incorrect as even if the offset is smaller than
len pKVM can still access out of bound memory in the next
ffa_host_unshare_ranges().

Split this check into 2:
1- Check that the fixed portion of the descriptor fits.
2- After getting reg, check the variable array size addr_range_cnt
   fits.

Also, drop the WARN_ONs as that will panic the kernel and in the
next checks there are no WARNs, so that makes it consistent.

Fixes: 0a9f15fd56 ("KVM: arm64: pkvm: Add support for fragmented FF-A descriptors")
Signed-off-by: Mostafa Saleh <smostafa@google.com>
Reviewed-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Sebastian Ene <sebastianene@google.com>
Link: https://patch.msgid.link/20260702103848.1647249-4-sebastianene@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-07-07 11:25:50 +01:00
Fuad Tabba
65a38ddeae KVM: arm64: selftests: Add MMIO sign-extending load test
Add a test for sign-extending MMIO loads (LDRSB, LDRSH, LDRSW) into Xt
and Wt destinations, with and without the sign bit set. The host supplies
the MMIO data and checks the guest register holds the sign-extended value.

Repeat the loads big-endian on a mixed-endian implementation. Issue those
at EL0: SCTLR_EL1.EE would make an EL1 load big-endian but also walk the
little-endian page tables big-endian, whereas SCTLR_EL1.E0E selects only
EL0 data endianness and leaves the walk little-endian.

Signed-off-by: Fuad Tabba <fuad.tabba@linux.dev>
Link: https://patch.msgid.link/20260706115522.954913-3-fuad.tabba@linux.dev
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-07-06 17:18:34 +01:00
Fuad Tabba
85f56708a4 KVM: arm64: Fix sign-extension of MMIO loads
A sign-extending load (LDRSB, LDRSH, LDRSW) from MMIO returns a
zero-extended value to the guest. The architecture performs such a load
as a memory read of the access size, then a sign-extension to the
register width. For LDRSH (DDI 0487 M.b C6.2.225, with the Mem accessor
at J1.2.3.111):

    data = Mem{16}(address, accdesc);
    X{regsize}(t) = SignExtend{regsize}(data);

The byte order is handled inside the Mem accessor, keyed on the access
size; the register width is separate, applied afterwards by SignExtend().

kvm_handle_mmio_return() runs these in the wrong order: it sign-extends
the access-width data, then calls vcpu_data_host_to_guest(), which masks
the value back to the access width (the size-keyed byte-order step). The
mask drops the sign bits that sign-extension produced.

Reorder so vcpu_data_host_to_guest() runs first, with the sign-extension
to register width after it. trace_kvm_mmio() moves with it and now logs
the access-width data before sign-extension.

Fixes: b30070862e ("ARM64: KVM: MMIO support BE host running LE code")
Reviewed-by: Oliver Upton <oupton@kernel.org>
Signed-off-by: Fuad Tabba <fuad.tabba@linux.dev>
Link: https://patch.msgid.link/20260706115522.954913-2-fuad.tabba@linux.dev
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-07-06 17:18:34 +01:00
Oliver Upton
f35c08c092 KVM: arm64: Only update XN attr when requested during S2 relaxation
On systems without DIC, KVM lazily grants execute permission to stage-2
translations after taking an instruction abort due to a permission
fault, allowing it to defer I-cache invalidations to the point they're
absolutely required.

If a data abort happens later down the line to such a translation, KVM
will not request execute permissions as part of the S2 relaxation on the
assumption that kvm_pgtable_stage2_relax_perms() does exactly what the
name implies and adds the requested permissions to the pre-existing
ones.

Avoid taking unintended execute permission faults by only preparing the
XN attribute if KVM_PGTABLE_PROT_X is set.

Fixes: 2608563b46 ("KVM: arm64: Add support for FEAT_XNX stage-2 permissions")
Signed-off-by: Oliver Upton <oupton@kernel.org>
Reviewed-by: Wei-Lin Chang <weilin.chang@arm.com>
Link: https://patch.msgid.link/20260701231620.3300204-3-oupton@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-07-06 17:17:38 +01:00
Oliver Upton
100baf0184 KVM: arm64: Ensure level is always initialized when relaxing perms
stage2_update_leaf_attrs() returns early before writing to @level if the
table walker returned an error. At the same time,
kvm_pgtable_stage2_relax_perms() uses the level as a TLBI TTL hint when the
error was EAGAIN, indicating the vCPU raced with a table update and the TLB
entry it hit is now stale.

Fall back to an unknown TTL if none was provided by the walk.

Cc: stable@vger.kernel.org
Fixes: be097997a2 ("KVM: arm64: Always invalidate TLB for stage-2 permission faults")
Signed-off-by: Oliver Upton <oupton@kernel.org>
Reviewed-by: Wei-Lin Chang <weilin.chang@arm.com>
Link: https://patch.msgid.link/20260701231620.3300204-2-oupton@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-07-06 17:17:38 +01:00
Marc Zyngier
3a07249981 KVM: Move kvm_io_bus_get_dev() locking responsibilities to callers
kvm_io_bus_get_dev() returns a device that is only matched by the
address, and nothing else. This can cause a lifetime issue if
the matched device is not the expected type, as by the time
the caller can introspect the object, it might be gone (the srcu
lock having been dropped).

Given that there is only a single user of this helper, the simplest
option is to move the locking responsibility to the caller, which
can keep the srcu lock held for as long as it wants.

Note that this aligns with other kvm_io_bus*() helpers, which
already require the srcu lock to be held by the callers.

Reported-by: Will Deacon <will@kernel.org>
Fixes: 8a39d00670 ("KVM: kvm_io_bus: Add kvm_io_bus_get_dev() call")
Link: https://lore.kernel.org/all/20260626111344.802555-1-maz@kernel.org
Cc: stable@vger.kernel.org
Reviewed-by: Oliver Upton <oupton@kernel.org>
Link: https://patch.msgid.link/20260627105105.1005990-1-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-07-06 17:15:57 +01:00
Bradley Morgan
d098bb75d1 KVM: arm64: account pKVM reclaim against the VM mm
Protected guest faults charge long term pins to the VM's mm. Teardown
can run later from file release, where current->mm may be unrelated.

Drop the charge from kvm->mm instead.

Fixes: 4e6e03f9ea ("KVM: arm64: Hook up reclaim hypercall to pkvm_pgtable_stage2_destroy()")
Signed-off-by: Bradley Morgan <include@grrlz.net>
Reviewed-by: Fuad Tabba <fuad.tabba@linux.dev>
Tested-by: Fuad Tabba <fuad.tabba@linux.dev>
Link: https://patch.msgid.link/20260621213155.6019-1-include@grrlz.net
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
2026-06-22 10:48:08 +01:00
Fuad Tabba
cbe2278aa3 KVM: arm64: Set IL in fake ESR for pKVM memory sharing exit
__pkvm_memshare_page_req() constructs a fake DABT ESR_EL2 to exit to
the host without setting IL. The ESR has ISV=0, so IL must be 1 per the
architecture. The host does not read IL on this path, but the
constructed syndrome should still be architecturally valid.

Set ESR_ELx_IL.

Fixes: 03313efed5 ("KVM: arm64: Implement the MEM_SHARE hypercall for protected VMs")
Signed-off-by: Fuad Tabba <tabba@google.com>
Link: https://patch.msgid.link/20260618121643.4105064-8-tabba@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-06-22 10:44:09 +01:00
Fuad Tabba
a69412287a KVM: arm64: Set IL for nested SError injection
kvm_inject_nested_serror() constructs an SError syndrome without IL.
The architecture mandates IL=1 for SError unconditionally.

Fixes: 77ee70a073 ("KVM: arm64: nv: Honor SError exception routing / masking")
Signed-off-by: Fuad Tabba <tabba@google.com>
Link: https://patch.msgid.link/20260618121643.4105064-7-tabba@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-06-22 10:44:08 +01:00
Fuad Tabba
7514f1785d KVM: arm64: Set IL for emulated SError injection
kvm_inject_serror_esr() constructs an SError syndrome without IL. The
architecture mandates IL=1 for SError unconditionally.

Fixes: f6e2262dfa ("KVM: arm64: Populate ESR_ELx.EC for emulated SError injection")
Signed-off-by: Fuad Tabba <tabba@google.com>
Link: https://patch.msgid.link/20260618121643.4105064-6-tabba@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-06-22 10:44:08 +01:00
Fuad Tabba
a52d6d68ad KVM: arm64: Set IL for injected FPAC exceptions during ERET emulation
The FPAC syndrome constructed during nested ERET emulation does not set
IL. For FPAC (EC=0x1C), IL reflects the instruction length. ERET and
its authenticated variants are always A64 32-bit instructions, so IL
must be 1.

Fixes: 213b3d1ea1 ("KVM: arm64: nv: Handle ERETA[AB] instructions")
Suggested-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Fuad Tabba <tabba@google.com>
Link: https://patch.msgid.link/20260618121643.4105064-5-tabba@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-06-22 10:44:08 +01:00
Fuad Tabba
add40af98b KVM: arm64: Unconditionally set IL for injected abort exceptions
inject_abt64() derives IL from the triggering trap's instruction length
(kvm_vcpu_trap_il_is32bit()), but the IL of the injected abort is fixed
by its EC, not by the triggering instruction. The architecture mandates
IL=1 for Instruction Aborts unconditionally and for Data Aborts with
ISV=0, and this function never sets ISV (the FSC is always EXTABT or
SEA_TTW). For a 16-bit T32 trap (a 32-bit EL0 task under an AArch64 EL1
guest) the trap has IL=0, so the abort is injected with the wrong IL.

Set ESR_ELx_IL unconditionally.

Fixes: aa8eff9bfb ("arm64: KVM: fault injection into a guest")
Signed-off-by: Fuad Tabba <tabba@google.com>
Link: https://patch.msgid.link/20260618121643.4105064-4-tabba@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-06-22 10:44:08 +01:00
Fuad Tabba
1d695dc827 KVM: arm64: Unconditionally set IL for injected undefined exceptions
inject_undef64() derives IL from the triggering trap's instruction
length (kvm_vcpu_trap_il_is32bit()), but the IL of the injected
exception is fixed by its EC, not by the triggering instruction. The
architecture mandates IL=1 for EC=0 (Unknown) unconditionally, so the
conditional is wrong. The undef-injection paths are not reached from
16-bit instructions, so there is no functional change today, but the
logic should not rely on that.

Set ESR_ELx_IL unconditionally.

Fixes: aa8eff9bfb ("arm64: KVM: fault injection into a guest")
Signed-off-by: Fuad Tabba <tabba@google.com>
Link: https://patch.msgid.link/20260618121643.4105064-3-tabba@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-06-22 10:44:08 +01:00
Fuad Tabba
daa71eca24 KVM: arm64: Set ESR_ELx.IL for injected undefined exceptions at EL2
inject_undef64() constructs an ESR with EC=0 (Unknown) but does not set
IL. The architecture mandates IL=1 for EC=0 unconditionally (ARM DDI
0487, ESR_ELx.IL description), so the injected syndrome is one that
conforming hardware cannot produce.

Set ESR_ELx_IL in the constructed syndrome.

Fixes: e5d40a5a97 ("KVM: arm64: pkvm: Add a generic synchronous exception injection primitive")
Reported-by: sashiko <sashiko@sashiko.dev>
Signed-off-by: Fuad Tabba <tabba@google.com>
Link: https://patch.msgid.link/20260618121643.4105064-2-tabba@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-06-22 10:44:08 +01:00
Oliver Upton
265b58aba5 KVM: arm64: nv: Mark VM as bugged for unexpected VNCR abort
KVM is unlikely to resolve an unexpected VNCR abort, meaning that
returning to the guest will likely leave the vCPU stuck in an abort
loop. Bug the VM and exit to userspace instead.

Signed-off-by: Oliver Upton <oupton@kernel.org>
Link: https://patch.msgid.link/20260618234207.1063941-6-oupton@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-06-22 10:43:25 +01:00
Oliver Upton
4bd7dbe0b2 KVM: arm64: nv: Inject SEA if guest VNCR isn't normal memory
When constructing an L1 VNCR mapping, KVM unconditionally uses cacheable
memory attributes, even if the underlying PFN isn't memory. This gets
particularly hairy if the endpoint doesn't support cacheable memory
attributes, potentially throwing an SError on writeback...

While KVM does permit cacheable memory attributes on certain PFNMAP
VMAs, kvm_translate_vncr() isn't currently grabbing the VMA. So do the
simpler thing for now and just reject everything that isn't memory.

Cc: stable@vger.kernel.org
Fixes: 2a359e0725 ("KVM: arm64: nv: Handle mapping of VNCR_EL2 at EL2")
Signed-off-by: Oliver Upton <oupton@kernel.org>
Link: https://patch.msgid.link/20260618234207.1063941-5-oupton@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-06-22 10:43:25 +01:00
Oliver Upton
bb645aa0a4 KVM: arm64: nv: Re-translate VNCR before injecting abort
KVM faults in the VNCR page with FOLL_WRITE whenever the guest aborts
for a write, similar to how a regular stage-2 mapping is handled. It is
entirely possible that the guest reads from the VNCR before writing to
it, in which case the PFN could only be read-only.

Invalidate the VNCR TLB and re-fetch the translation upon taking a VNCR
abort, allowing the host mapping to be faulted in for write the second
time around. Interestingly enough, this also satisfies the ordering
requirements of FEAT_ETS2/3 between descriptor updates and MMU faults.

Cc: stable@vger.kernel.org
Fixes: 2a359e0725 ("KVM: arm64: nv: Handle mapping of VNCR_EL2 at EL2")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Signed-off-by: Oliver Upton <oupton@kernel.org>
Link: https://patch.msgid.link/20260618234207.1063941-4-oupton@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-06-22 10:43:25 +01:00
Oliver Upton
9f3e83345a KVM: arm64: nv: Inject SEA if kvm_translate_vncr() can't resolve PFN
kvm_handle_vncr_abort() assumes that s1_walk_result conveys an abort
when kvm_translate_vncr() returns -EFAULT. This is not always the case
as it's possible to encounter 'late' failures on the output of S1
translation, e.g. a GFN outside of the memslots.

Fix it by preparing an external abort before returning from
kvm_translate_vncr(). Get rid of the BUG_ON() in the fault injection
path while at it.

Cc: stable@vger.kernel.org
Fixes: 2a359e0725 ("KVM: arm64: nv: Handle mapping of VNCR_EL2 at EL2")
Signed-off-by: Oliver Upton <oupton@kernel.org>
Link: https://patch.msgid.link/20260618234207.1063941-3-oupton@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-06-22 10:43:25 +01:00
Oliver Upton
2684e02bac KVM: arm64: nv: Respect read-only PFN when mapping L1 VNCR
KVM currently maps the L1 VNCR into the host stage-1 by relying entirely
on the permissions of the guest stage-1. At the same time, it is
entirely possible that the backing PFN is read-only (e.g. RO memslot),
meaning that the L1 VNCR should use at most a read-only mapping.

Cache the writability of the PFN in the VNCR TLB and use it to constrain
the resulting fixmap permissions. Promote VNCR permission faults to an
SEA in the case where the guest attempts to write to a read-only
endpoint. Conveniently, this also plugs a page leak found by Sashiko [*]
resulting from the early return for a read-only PFN.

Cc: stable@vger.kernel.org
Fixes: 2a359e0725 ("KVM: arm64: nv: Handle mapping of VNCR_EL2 at EL2")
Link: https://lore.kernel.org/kvm/20260608082603.16AEC1F00893@smtp.kernel.org/
Signed-off-by: Oliver Upton <oupton@kernel.org>
Link: https://patch.msgid.link/20260618234207.1063941-2-oupton@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-06-22 10:43:25 +01:00
Fuad Tabba
fcda30b134 KVM: arm64: Add Fuad Tabba as a reviewer
I have been working on KVM/arm64 for a couple of years, mostly on
pKVM, and am currently upstreaming protected guest support, with more
to come later. I already review KVM/arm64 patches more broadly, and
am happy to continue doing so in an official capacity.

Add myself to the KVM/arm64 reviewer list.

Signed-off-by: Fuad Tabba <tabba@google.com>
Acked-by: Oliver Upton <oupton@kernel.org>
Link: https://patch.msgid.link/20260617131237.2842619-1-tabba@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-06-17 18:42:38 +01:00
Fuad Tabba
0e8e955b9b KVM: arm64: nv: Fix PSTATE construction on illegal exception return
kvm_check_illegal_exception_return() sourced the flags {N,Z,C,V} and
masks {D,A,I,F} of the resulting PSTATE from the current PSTATE, but
R_VWJHB takes them from the SPSR being returned to and leaves
PSTATE.{EL,SP,nRW} (and EXLOCK when FEAT_GCS) unchanged. PAN, ALLINT
and PM were not applied at all.

Build the PSTATE by taking those fields from the SPSR while preserving
EL, SP, nRW and EXLOCK from the current PSTATE, then set IL.

Fixes: 47f3a2fc76 ("KVM: arm64: nv: Support virtual EL2 exceptions")
Suggested-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/all/86wlvxs5r0.wl-maz@kernel.org/
Signed-off-by: Fuad Tabba <tabba@google.com>
Link: https://patch.msgid.link/20260617144907.2972095-1-tabba@google.com
[maz: tidied things a bit]
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-06-17 18:34:47 +01:00
Fuad Tabba
ec40342aac KVM: arm64: Sync SPSR_EL1 when injecting an exception into a pVM
When pKVM injects a synchronous exception into a protected guest, it
re-enters without restoring the guest's EL1 sysregs and writes the EL1
exception registers to hardware by hand: ESR_EL1 and ELR_EL1, but not
SPSR_EL1. enter_exception64() sets SPSR_EL1 (the interrupted PSTATE)
only in memory, so the guest's handler reads a stale SPSR_EL1 and
restores the wrong PSTATE on eret.

Write SPSR_EL1 alongside the other exception registers.

Fixes: 6c30bfb18d ("KVM: arm64: Add handlers for protected VM System Registers")
Reported-by: sashiko <sashiko@sashiko.dev>
Signed-off-by: Fuad Tabba <tabba@google.com>
Acked-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260612113414.1022901-1-tabba@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-06-17 13:40:18 +01:00
Fuad Tabba
e2cb1f4578 KVM: arm64: nv: Write ESR_EL2 for injected nested SError exceptions
kvm_inject_el2_exception() writes ESR_EL2 for synchronous exceptions
but not for SError. enter_exception64() does not write ESR_ELx for any
exception type, so the constructed syndrome is dropped. A guest L2
hypervisor taking a nested SError observes stale ESR_EL2.

This affects both kvm_inject_nested_serror() and the EASE path in
kvm_inject_nested_sea().

Write ESR_EL2 for except_type_serror, matching except_type_sync.

Fixes: 77ee70a073 ("KVM: arm64: nv: Honor SError exception routing / masking")
Reported-by: sashiko <sashiko@sashiko.dev>
Signed-off-by: Fuad Tabba <tabba@google.com>
Link: https://patch.msgid.link/20260615131116.390977-1-tabba@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
2026-06-17 12:58:40 +01:00
Oliver Upton
9f1667098c KVM: arm64: nv: Drop bogus WARN for write to ZCR_EL2
It is entirely possible for a guest to write to the ZCR_EL2 sysreg alias
while in a nested context, as it is expected if FEAT_NV2 is advertised
to the L1 hypervisor.

Get rid of the bogus WARN which, since the hyp vectors were installed at
this point, has the effect of a hyp_panic...

Cc: stable@vger.kernel.org
Fixes: 0cfc85b8f5 ("KVM: arm64: nv: Load guest FP state for ZCR_EL2 trap")
Signed-off-by: Oliver Upton <oupton@kernel.org>
Link: https://patch.msgid.link/20260615051324.830045-1-oupton@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-06-17 12:49:11 +01:00
Weiming Shi
ff1022c3de KVM: arm64: nv: Fix SPSR_EL2 restore in kvm_hyp_handle_mops()
kvm_hyp_handle_mops() resets the single-step state machine as part of
rewinding state for a MOPS exception by modifying vcpu_cpsr() and
writing the result directly into hardware.

In the case of nested virtualization, vcpu_cpsr() is a synthetic value
such that the rest of KVM can deal with vEL2 cleanly. That means the
value requires translation before being written into hardware, which is
unfortunately missing from the MOPS handler.

Fix it by directly modifying SPSR_EL2 and avoiding the synthetic state
altogether, which will be resynchronized on the next 'full' exit back
to KVM.

Fixes: 2de451a329 ("KVM: arm64: Add handler for MOPS exceptions")
Reported-by: Zhong Wang <wangzhong.c0ss4ck@bytedance.com>
Reported-by: Xuanqing Shi <shixuanqing.11@bytedance.com>
Link: https://lore.kernel.org/all/ajE4lHQevXNHpl1M@Air.local/
Cc: stable@vger.kernel.org
Signed-off-by: Weiming Shi <bestswngs@gmail.com>
Link: https://patch.msgid.link/20260617040820.2194831-2-bestswngs@gmail.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-06-17 12:49:11 +01:00
Hyunwoo Kim
0074b82cdf KVM: arm64: vgic: Check the interrupt is still ours before migrating it
vgic_prune_ap_list() drops both ap_list_lock and irq_lock while migrating
an interrupt to another vCPU. After reacquiring the locks it only checks
that the affinity is unchanged (target_vcpu == vgic_target_oracle(irq))
before moving the interrupt, which assumes that an interrupt whose affinity
is preserved is still queued on this vCPU's ap_list.

That assumption no longer holds if the interrupt is taken off the ap_list
while the locks are dropped. vgic_flush_pending_lpis() removes the
interrupt from the list and sets irq->vcpu to NULL, but leaves
enabled/pending/target_vcpu untouched. As the interrupt is still enabled
and pending, vgic_target_oracle() returns the same target_vcpu, so the
affinity check passes and list_del() is run a second time on an entry that
has already been removed.

Also check that the interrupt is still assigned to this vCPU
(irq->vcpu == vcpu) before moving it.

Fixes: 0919e84c0f ("KVM: arm/arm64: vgic-new: Add IRQ sync/flush framework")
Signed-off-by: Hyunwoo Kim <imv4bel@gmail.com>
Link: https://patch.msgid.link/aiHnI1mu6SGQrgnz@v4bel
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
2026-06-17 12:49:11 +01:00
Marc Zyngier
7258770e58 KVM: arm64: vgic: Handle race between interrupt affinity change and LPI disabling
Hyunwoo Kim reports some really bad races should the following
situation occur:

- LPI-I is pending in vcpu-B's AP list
- vcpu-A writes to vcpu-B's RD to disable its LPIs
- vcpu-C moves I from B to C

If the last two race nicely enough, vgic_prune_ap_list() can drop
the irq and AP list locks, reacquire them, and in the interval
the irq has been freed. UAF follows.

The fix is two-fold:

- Before dropping the irq and ap_list locks, take a reference on
  the irq

- Do not try to handle migration of the pending bit: there is no
  expectation that this state is retained, as per the architecture

With that, we're sure that the interrupt is still around, and we
safely remove it from the AP list as it has no target at this
stage (unless another interrupt fires, but that's another story).

Reported-by: Hyunwoo Kim <imv4bel@gmail.com>
Tested-by: Hyunwoo Kim <imv4bel@gmail.com>
Link: https://lore.kernel.org/r/ailsCnyoS82r_QRz@v4bel
Link: https://patch.msgid.link/20260615181625.3029352-1-maz@kernel.org
Fixes: 5dd4b924e3 ("KVM: arm/arm64: vgic: Add refcounting for IRQs")
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
2026-06-17 12:49:07 +01:00
Marc Zyngier
1ee27dacbe Merge branch kvm-arm64/nv-mmu-7.2 into kvmarm-master/next
* kvm-arm64/nv-mmu-7.2:
  : .
  : Assorted collection of fixes for NV MMU bugs
  :
  : - Correctly plug AT S1E1A handling in the emulation backend
  :
  : - Make CPTR_EL2.E0POE depend on FEAT_S1POE
  :
  : - Drop the reference on the page if the VNCR translation
  :   races with an MMU notifier
  :
  : - Correctly synthesise an SEA if a page table walk fails due
  :   to a guest error
  :
  : - Fully invalidate the VNCR TLB and fixmap when translating
  :   for a new VNCR
  :
  : - Restart S1 walk when the S2 walk fails due to a race condition
  :
  : - Correctly return -EAGAIN when a S1 walk fails
  :
  : - Fix block mapping validity check in stage-1 walker for 64kB pages
  :
  : - Fix potential NULL dereference when performing an EL2 TLBI targeting
  :   the VNCR page
  :
  : - Hold kvm->mmu_lock while initialising the vncr_tlb pointer
  : .
  KVM: arm64: nv: Hold kvm->mmu_lock while initialising vcpu->arch.vncr_tlb
  KVM: arm64: nv: Avoid dereferencing NULL VNCR pseudo-TLB
  KVM: arm64: Fix block mapping validity check in stage-1 walker
  KVM: arm64: nv: Restart stage-1 walk if stage-2 desc update fails
  KVM: arm64: Restart instruction upon race in __kvm_at_s12()
  KVM: arm64: nv: Inject SEA TTW when desc update can't write to GPA
  KVM: arm64: nv: Fully update VNCR fixmap state in kvm_translate_vncr()
  KVM: arm64: Don't leak PFN when kvm_translate_vncr() races MMU notifier
  arm64: cpufeature: Expose ID_AA64ISAR2_EL1.ATS1A to KVM
  KVM: arm64: Wire AT S1E1A in the system instruction handling table
  KVM: arm64: Key CPTR_EL2.E0POE propagation on FEAT_S1POE

Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-06-12 09:29:34 +01:00
Marc Zyngier
bd2ed0733b Merge branch kvm-arm64/misc-7.2 into kvmarm-master/next
* kvm-arm64/misc-7.2:
  : .
  : - Check for a valid vcpu pointer upon deactivating traps when handling
  :   a HYP panic in VHE mode
  :
  : - Make the __deactivate_fgt() macro use its arguments instead of the
  :   surrounding context
  :
  : - Don't bother with initialising TPIDR_EL2 in the hyp stubs, as this
  :   is already taken care of in more obvious places
  :
  : - Drop the unused kvm_arch pointer passed to __load_stage2()
  :
  : - Return -EOPNOTSUPP when a hypercall fails for some reason, instead of
  :   returning whatever was in the result structure
  :
  : - Make the ITS ABI selection helpers return void, which avoids wondering
  :   about the nature of the return code (always 0)
  : .
  KVM: arm64: vgic-its: Make ABI commit helpers return void
  KVM: arm64: Set a Linux errno on SMCCC error in kvm_call_hyp_nvhe()
  KVM: arm64: Remove @arch from __load_stage2()
  KVM: arm64: Don't populate TPIDR_EL2 in finalise_el2()
  KVM: arm64: Fix __deactivate_fgt macro parameter typo
  KVM: arm64: Guard against NULL vcpu on VHE hyp panic path

Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-06-12 09:29:31 +01:00
Marc Zyngier
8411f1534a Merge branch kvm-arm64/vgic-v5-PPI-fixes into kvmarm-master/next
* kvm-arm64/vgic-v5-PPI-fixes:
  : .
  : Substantial cleanup of the vgic-v5 PPI support. From the original
  : cover letter:
  :
  : "With the GICv5 PPi support merged in, it has become obvious that a few
  :  things could be improved, both from the correctness and maintainability
  :  angles."
  : .
  KVM: arm64: Fix arch timer interrupts for GICv3-on-GICv5 guests
  irqchip/gic-v5: Immediately exec priority drop following activate
  Documentation: KVM: Clarify that PMU_V3_IRQ IntID requirements for GICv5
  Documentation: KVM: Fix typos in VGICv5 documentation
  KVM: arm64: selftests: Improve error handling for GICv5 PPI selftest
  KVM: arm64: selftests: Cleanup unused vars in GICv5 PPI selftest
  KVM: arm64: selftests: Add missing GIC CDEN to no-vgic-v5 selftest
  KVM: arm64: vgic-v5: Atomically assign bits to PPI DVI bitmap
  KVM: arm64: vgic-v5: Add missing trap handing for NV triage
  KVM: arm64: vgic-v5: Limit support to 64 PPIs
  KVM: arm64: vgic: Rationalise per-CPU irq accessor
  KVM: arm64: vgic-v5: Drop defensive checks from vgic_v5_ppi_queue_irq_unlock()
  KVM: arm64: vgic: Consolidate vgic_allocate_private_irqs_locked()
  KVM: arm64: vgic: Constify struct irq_ops usage
  KVM: arm64: vgic-v5: Drop pointless ARM64_HAS_GICV5_CPUIF check
  KVM: arm64: vgic-v5: Remove use of __assign_bit() with a constant
  KVM: arm64: vgic-v5: Move PPI caps into kvm_vgic_global_state
  KVM: arm64: vgic-v5: Add for_each_visible_v5_ppi() iterator

Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-06-12 09:08:31 +01:00
Marc Zyngier
35c060e8d6 Merge branch kvm-arm64/pkvm-fixes-7.2 into kvmarm-master/next
* kvm-arm64/pkvm-fixes-7.2:
  : .
  : Assorted pKVM fixes for 7.2:
  :
  : - Ensure that the vcpu memcache is filled in a number of cases (donate,
  :   share, selftest)
  :
  : - Fix vmemmap page order handling by resetting it when initialising the
  :   memory pool
  :
  : - Don't leak page references on failed memory donation
  :
  : - Add sanity-check for refcounted pages when donating/sharing pages
  :
  : - Clear __hyp_running_vcpu on state flush
  :
  : - Check LR upper bound against a trusted value
  :
  : - Assorted fixes for the host-side tracking of the pages shared with
  :   EL2 as a result of some Sashiko testing from Fuad
  :
  : - Correctly forward HCR_EL2.VSE from host to guest, so that protected
  :   guests can see SErrors
  : .
  KVM: arm64: Roll back partial shares on kvm_share_hyp() failure
  KVM: arm64: Avoid host/hyp share desync on unshare hypercall failure
  KVM: arm64: Free hyp-share tracking node when share hypercall fails
  KVM: arm64: Flush HCR_EL2.VSE to deliver SErrors to pKVM guests
  KVM: arm64: Bound used_lrs when flushing the pKVM hyp vCPU
  KVM: arm64: Clear __hyp_running_vcpu when flushing the pKVM hyp vCPU
  KVM: arm64: Pre-check vcpu memcache for host->guest donate
  KVM: arm64: Pre-check vcpu memcache for host->guest share
  KVM: arm64: Seed pkvm_ownership_selftest vcpu memcache
  KVM: arm64: Add fail-safe for refcounted pages in __pkvm_hyp_donate_host
  KVM: arm64: Fix __pkvm_init_vm error path
  KVM: arm64: Reset page order in pKVM hyp_pool

Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-06-12 09:08:25 +01:00
Marc Zyngier
27086d066d Merge branch kvm-arm64/nv-granule-sizes into kvmarm-master/next
* kvm-arm64/nv-granule-sizes:
  : .
  : Tidying up of the behaviour when the selected page size in not
  : implemented, courtesy of Wei-Lin Chang. From the initial cover
  : letter:
  :
  : "This small series fixes the granule size selection for software stage-1
  :  and stage-2 walks. Previously we treat the guest's TCR/VTCR.TGx as-is
  :  and use the encoded granule size for the walks. However this is
  :  incorrect if the granule sizes are not advertised in the guest's
  :  ID_AA64MMFR0_EL1.TGRAN*. The architecture specifies that when an
  :  unsupported size is programed in TGx, it must be treated as an
  :  implemented size. Fix this by choosing an available one while
  :  prioritizing PAGE_SIZE."
  : .
  KVM: arm64: Fallback to a supported value for unsupported guest TGx
  KVM: arm64: nv: Use literal granule size in TLBI range calculation
  KVM: arm64: Factor out TG0/1 decoding of VTCR and TCR
  KVM: arm64: nv: Rename vtcr_to_walk_info() to setup_s2_walk()

Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-06-12 09:04:24 +01:00
Marc Zyngier
d1f0ed520b Merge branch kvm-arm64/nv-fp-elision into kvmarm-master/next
* kvm-arm64/nv-fp-elision:
  : .
  : Significantly reduce the overhead of the context switch between L1 and
  : L2 guests by eliding the save/restore of the FP/SIMD/SVE registers, as
  : this state is shared between the two guests, and therefore can be left
  : live.
  : .
  KVM: arm64: nv: Don't save/restore FP register during a nested ERET or exception
  KVM: arm64: nv: Track L2 to L1 exception emulation

Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-06-12 09:03:57 +01:00
Marc Zyngier
a1b504eda4 Merge branch kvm-arm64/no-lazy-vgic-init into kvmarm-master/next
* kvm-arm64/no-lazy-vgic-init:
  : .
  : Fix an ugly situation where the vgic lazy init could happen in
  : non-preemtible contexts such as vcpu reset, resulting in lockdep
  : splats.
  :
  : This requires revamping the way in-kernel emulation of devices
  : (timers, PMU) are presenting their interrupt to the vgic, and
  : make sure there is no need to init the vgic on the back of that.
  : .
  KVM: arm64: vgic-v2: Don't init the vgic on in-kernel interrupt injection
  KVM: arm64: vgic-v2: Force vgic init on injection outside the run loop
  KVM: arm64: pmu: Kill the PMU interrupt level cache
  KVM: arm64: timer: Kill the per-timer irq level cache
  KVM: arm64: Simplify userspace notification of interrupt state
  KVM: arm64: timer: Repaint kvm_timer_{should,irq_can}_fire() to kvm_timer_{pending,enabled}()

Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-06-12 09:03:24 +01:00
Jackie Liu
650c4704b9 KVM: arm64: vgic-its: Make ABI commit helpers return void
The return values of vgic_its_set_abi() and vgic_its_commit_v0() are always
0 and do not carry useful error information. Simplify by changing them to
void.

Suggested-by: Oliver Upton <oupton@kernel.org>
Signed-off-by: Jackie Liu <liuyun01@kylinos.cn>
Reviewed-by: Oliver Upton <oupton@kernel.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Link: https://patch.msgid.link/20260604075147.53299-1-liu.yun@linux.dev
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-06-12 09:01:21 +01:00
Marc Zyngier
4b54e2374d KVM: arm64: nv: Hold kvm->mmu_lock while initialising vcpu->arch.vncr_tlb
Sashiko reports that there is a race between initialising vncr_tlb
and making use of it, as we don't hold the mmu_lock at this point.

Additionally, it identifies a memory leak, should userspace repeatedly
invokes the KVM_RUN ioctl after a failure of kvm_arch_vcpu_run_pid_change(),
as we assign vncr_tlb blindly on first run, irrespective of prior
allocations.

Slap the two bugs in one go by taking the kvm->mmu_lock on assigning
vncr_tlb, preventing the race for good, and by checking that vncr_tlb
is indeed NULL prior to allocation.

Reported-by: Sashiko <sashiko-bot@kernel.org>
Link: https://lore.kernel.org/r/20260607180815.85FBC1F00893@smtp.kernel.org
Reviewed-by: Oliver Upton <oupton@kernel.org>
Link: https://patch.msgid.link/20260608081108.2244133-1-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-06-10 13:01:12 +01:00
Marc Zyngier
4be6cbeb93 KVM: arm64: nv: Avoid dereferencing NULL VNCR pseudo-TLB
VNCR TLB invalidation occurs from MMU notifiers or TLBI instructions,
and either can race against a vcpu not being onlined yet (no pseudo-TLB
allocated). Similarly, the TLB might be invalid, and the invalidation
should be skipped in this case.

Both kvm_invalidate_vncr_ipa() and kvm_invalidate_vncr_va() are
expected to perform the same checks, except that the latter doesn't
check for the allocation and blindly dereferences the pointer.

Solve this by introducing a new iterator built on top of the usual
kvm_for_each_vcpu() that checks for both of the above conditions,
and convert the two users to it.

Reported-by: Hyunwoo Kim <imv4bel@gmail.com>
Link: https://lore.kernel.org/r/aiUvSbrWndQeUPc8@v4bel
Fixes: 4ffa72ad8f ("KVM: arm64: nv: Add S1 TLB invalidation primitive for VNCR_EL2")
Cc: stable@vger.kernel.org
Reviewed-by: Oliver Upton <oupton@kernel.org>
Link: https://patch.msgid.link/20260607175745.297793-1-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-06-10 11:51:03 +01:00
Wei-Lin Chang
6bef47288c KVM: arm64: Fix block mapping validity check in stage-1 walker
For the 64K granule size, FEAT_LPA determines whether a level 1 mapping
is allowed. Using the result of has_52bit_pa() is too restrictive, as it
also checks the selected output addressi size in TCR.(I)PS. Fix it by
only checking FEAT_LPA.

Fixes: 5da3a3b27a ("KVM: arm64: Expand valid block mappings to FEAT_LPA/LPA2 support")
Signed-off-by: Wei-Lin Chang <weilin.chang@arm.com>
Link: https://patch.msgid.link/20260605185255.2431996-1-weilin.chang@arm.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-06-07 15:10:59 +01:00
Vincent Donnefort
3190bd7d36 KVM: arm64: Set a Linux errno on SMCCC error in kvm_call_hyp_nvhe()
If kvm_call_hyp_nvhe() fails with an SMCCC error code, we WARN().
However, the returned value isn't initialized and the caller might get
garbage or 0 which is likely to be interpreted as success.

Set a default -EOPNOTSUPP error value, ensuring all callers get the
message when hypercalls fail.

Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Acked-by: Will Deacon <will@kernel.org>
Reviewed-by: Fuad Tabba <tabba@google.com>
Link: https://patch.msgid.link/20260603110312.2909844-1-vdonnefort@google.com
[maz: changed error value to -EOPNOTSUPP as suggested by Will,
 tidied up change log]
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-06-07 14:58:00 +01:00
tabba@google.com
f4411f9308 KVM: arm64: Roll back partial shares on kvm_share_hyp() failure
kvm_share_hyp() shares a range one page at a time. If share_pfn_hyp()
fails partway through, the pages already shared by this call are left
shared, while the caller treats the whole range as failed and never
unshares them.

Unshare those pages before returning the error. If an unshare itself
fails the page is leaked: it stays shared with the hypervisor and is
no longer reusable for pKVM, but no isolation guarantee is broken, so
WARN and continue. Not expected in practice.

Fixes: a83e2191b7 ("KVM: arm64: pkvm: Refcount the pages shared with EL2")
Suggested-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Vincent Donnefort <vdonnefort@google.com>
Link: https://patch.msgid.link/20260529121755.2923500-4-tabba@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-06-07 14:38:56 +01:00
tabba@google.com
bd2618780a KVM: arm64: Avoid host/hyp share desync on unshare hypercall failure
unshare_pfn_hyp() erases the tracking node from hyp_shared_pfns
and frees it before invoking __pkvm_host_unshare_hyp. If the
hypercall fails (e.g. EL2 refcount still held, or page-state
mismatch), the host loses its record while EL2 still holds the
share, breaking later share/unshare attempts on the same pfn.

Invoke the hypercall first; erase and free only on success.

Document at the kvm_unshare_hyp() call site that the WARN_ON() is
left non-fatal: a failed unshare leaks the page (it stays shared
with the hypervisor) but breaks no isolation guarantee.

Fixes: 52b28657eb ("KVM: arm64: pkvm: Unshare guest structs during teardown")
Reported-by: Sashiko (local):gemini-3.1-pro
Suggested-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Vincent Donnefort <vdonnefort@google.com>
Link: https://patch.msgid.link/20260529121755.2923500-3-tabba@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-06-07 14:38:56 +01:00
tabba@google.com
63336d57a2 KVM: arm64: Free hyp-share tracking node when share hypercall fails
share_pfn_hyp() inserts a tracking node into hyp_shared_pfns and
then invokes __pkvm_host_share_hyp. If the hypercall rejects the
share (page-state mismatch at EL2), the node stays in the tree
with refcount 1: a phantom share that leaks the allocation and
that a later unshare will trust.

Erase the node and free it on hypercall failure.

Fixes: a83e2191b7 ("KVM: arm64: pkvm: Refcount the pages shared with EL2")
Reported-by: Sashiko (local):gemini-3.1-pro
Suggested-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Vincent Donnefort <vdonnefort@google.com>
Link: https://patch.msgid.link/20260529121755.2923500-2-tabba@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-06-07 14:38:56 +01:00
tabba@google.com
832dfa237f KVM: arm64: Flush HCR_EL2.VSE to deliver SErrors to pKVM guests
With pKVM enabled, the host injects a virtual SError by setting
HCR_EL2.VSE on its vCPU copy, but flush_hyp_vcpu() only flows TWI/TWE
into the hyp vCPU that runs, so VSE never reaches it and a deferred
(masked) SError is never delivered. VSE is a host-owned injection
control, not a trap-configuration bit, so restricting the host's
trap-register values should not have dropped it.

Flow it on entry; sync_hyp_vcpu() already copies hcr_el2 back, so
delivery is reflected to the host. THis makes it consistent with
the existing forwarding of VSESR_EL2, which qualifies the Serror.

Fixes: b56680de9c ("KVM: arm64: Initialize trap register values in hyp in pKVM")
Reported-by: Sashiko (local):gemini-3.1-pro
Signed-off-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Oliver Upton <oupton@kernel.org>
Link: https://patch.msgid.link/20260531154548.1505799-1-tabba@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-06-07 14:34:53 +01:00
Hyunwoo Kim
8cc8bbbfab KVM: arm64: Bound used_lrs when flushing the pKVM hyp vCPU
flush_hyp_vcpu() copies the host vGIC state into the hyp's private vCPU
on every run. The vGIC list register save and restore use used_lrs as
their loop bound and expect it to stay within the number of implemented
list registers. While this is generally the case, flush_hyp_vcpu()
copies vgic_v3 verbatim and does not enforce this, so a value provided
by the host is used at EL2 to index vgic_lr[] and access ICH_LR<n>_EL2
(host -> EL2).

Fix by clamping used_lrs to the number of implemented list registers
after the copy, as the trusted path already does in
vgic_flush_lr_state(). The number of implemented list registers is
constant after init, so it is replicated once from
kvm_vgic_global_state.nr_lr into hyp_gicv3_nr_lr rather than read on
every entry.

Cc: stable@vger.kernel.org
Fixes: be66e67f17 ("KVM: arm64: Use the pKVM hyp vCPU structure in handle___kvm_vcpu_run()")
Signed-off-by: Hyunwoo Kim <imv4bel@gmail.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Link: https://patch.msgid.link/20260606175614.83273-3-imv4bel@gmail.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-06-07 14:07:06 +01:00
Hyunwoo Kim
e8042f6e1d KVM: arm64: Clear __hyp_running_vcpu when flushing the pKVM hyp vCPU
flush_hyp_vcpu() copies the host vCPU context into the hyp's private
vCPU on every run. ctxt_to_vcpu() expects a guest context to have a
NULL __hyp_running_vcpu, which is only ever set on the host context, so
that it resolves the vCPU via container_of(). While this is generally
the case, flush_hyp_vcpu() copies the context verbatim and does not
enforce this, so a value provided by the host is dereferenced at EL2
(host -> EL2).

Fix by clearing __hyp_running_vcpu after the copy.

Cc: stable@vger.kernel.org
Fixes: be66e67f17 ("KVM: arm64: Use the pKVM hyp vCPU structure in handle___kvm_vcpu_run()")
Signed-off-by: Hyunwoo Kim <imv4bel@gmail.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Link: https://patch.msgid.link/20260606175614.83273-2-imv4bel@gmail.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-06-07 14:07:06 +01:00