- Move locking for kvm_io_bus_get_dev() into the caller, ensuring
race-free checks that the returned object is of the correct type
- Fix initialisation of the page-table walk level when relaxing
permissions
- Correctly update the XN attribute when relaxing permissions
- Fix the sign extension of loads from emulated MMIO regions
- Assorted collection of fixes for pKVM's FFA proxy, together with a
couple of FFA driver adjustments
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Merge tag 'kvmarm-fixes-7.2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm64 fixes for 7.2, take #2
- Move locking for kvm_io_bus_get_dev() into the caller, ensuring
race-free checks that the returned object is of the correct type
- Fix initialisation of the page-table walk level when relaxing
permissions
- Correctly update the XN attribute when relaxing permissions
- Fix the sign extension of loads from emulated MMIO regions
- Assorted collection of fixes for pKVM's FFA proxy, together with a
couple of FFA driver adjustments
- Fix an accounting buglet when reclaiming pages from a protected
guest
- Fix a bunch of architectural compliance issues when injecting a
synthesised exception, most of which were missing the PSTATE.IL bit
indicating a 32bit-wide instruction
- Another set of fixes addressing issues with translation of VNCR_EL2,
including corner cases where the guest point that register at a RO
page...
- Don't warn when trapping accesses to ZCR_EL2 from an L2 guest, as
that's not unexpected at all
- Address a bunch of races with LPI migration vs LPIs being disabled
- Fix a total howler of a bug combining FEAT_MOPS and NV, resulting in
exception returning in the wrong place...
- Coerce Fuad Tabba into a reviewer role, and may his Inbox catch
fire!
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Merge tag 'kvmarm-fixes-7.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm64 fixes for 7.2, take #1
- Fix an accounting buglet when reclaiming pages from a protected
guest
- Fix a bunch of architectural compliance issues when injecting a
synthesised exception, most of which were missing the PSTATE.IL bit
indicating a 32bit-wide instruction
- Another set of fixes addressing issues with translation of VNCR_EL2,
including corner cases where the guest point that register at a RO
page...
- Don't warn when trapping accesses to ZCR_EL2 from an L2 guest, as
that's not unexpected at all
- Address a bunch of races with LPI migration vs LPIs being disabled
- Fix a total howler of a bug combining FEAT_MOPS and NV, resulting in
exception returning in the wrong place...
- Coerce Fuad Tabba into a reviewer role, and may his Inbox catch
fire!
Assigning the invalidation level (an s8 value) with TLBI_TTL_UNKNOWN
(a 32bit signed value) is not ideal, to say the least. Instead of
this, only pass TLBI_TTL_UNKNOWN to __kvm_tlb_flush_vmid_ipa_nsh()
when we know for sure that we don't have a provided level.
Fixes: 100baf0184 ("KVM: arm64: Ensure level is always initialized when relaxing perms")
Reported-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Oliver Upton <oupton@kernel.org>
Link: https://lore.kernel.org/r/akztC7H2IsEKaq4i@sirena.org.uk
Link: https://patch.msgid.link/20260707162935.1900874-1-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
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>
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>
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>
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>
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>
__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>
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>
"This is a bit of an odd merge window on the KVM/arm64 front. There is
absolutely no new feature in the pull request. It is purely fixes,
because it is simply becoming too hard to review new stuff when so
many AI-fuelled fixes hit the list".
- Significant cleanup of the vgic-v5 PPI support which was merged in
7.1. This makes the code more maintainable, and squashes a couple
of bugs in the meantime.
- Set of fixes for the handling of the MMU in an NV context,
particularly VNCR-triggered faults. S1POE support is fixed
as well.
- Large set of pKVM fixes, mostly addressing recurring issues
around hypervisor tracking of donated pages in obscure cases
where the donation could fail and leave things in a bizarre
state.
- Fixes for the so-called "lazy vgic init", which resulted in
sleeping operations in non-preemptible sections. This turned
out to be far more invasive than initially expected...
- Reduce the overhead of L1/L2 context switch by not touching
the FP registers.
- Fix the way non-implemented page sizes are dealt with when
a guest insist on using them for S2 translation.
- The usual set of low-impact fixes and cleanups all over the map.
Loongarch:
- On a request for lazy FPU load, load all FPU state that the VM
supports instead of enabling only the part (FPU, LSX or LASX)
that caused the FPU load request.
- Some enhancements about interrupt injection.
- Some bug fixes and other small changes.
RISC-V:
- Batch G-stage TLB flushes for GPA range based page table updates
- Convert HGEI line management to fully per-HART
- Fix missing CSR dirty marking when FWFT state updated via ONE_REG
- Fix stale FWFT feature exposure to Guest/VM
- Speed up dirty logging write faults using MMU rwlock and atomic
PTE updates using cmpxchg() for permission-only changes
- Use flexible array for APLIC IRQ state
- Use kvm_slot_dirty_track_enabled() for logging enable check on
a memslot
- Avoid skipping valid pages in kvm_riscv_gstage_wp_range()
- Avoid skipping valid pages in kvm_riscv_gstage_unmap_range()
- Use endian-specific __lelong for NACL shared memory
S390:
- KVM_PRE_FAULT_MEMORY support
- Support for 2G hugepages
- Support for the ASTFLEIE 2 facility
- Support for fast inject using kvm_arch_set_irq_inatomic
- Fix potential leak of uninitialized bytes
- A few more misc gmap fixes.
x86:
- Generic support for the more granular permissions allowed by EPT,
namely "read" (which was previously usurping the U bit) and
separate execution bits for kernel and userspace.
- Do not assume that all page tables start with U=1/W=1/NX=0 at the
root, as AMD GMET needs to have U=0 at the root.
- Introduce common assembly macros for use within Intel and AMD
vendor-specific vmentry code. This touches the SPEC_CTRL handling,
which is now entirely done in assembly for Intel (by reusing the
AMD code that already existed), and register save/restore which
uses some macro magic to compute the offsets in the struct. Both
of these are preparatory changes for upcoming APX support.
- Clean up KVM's register tracking and storage, primarily to prepare for
APX support, which expands the maximum number of GPRs from 16 to 32.
- Keep a single copy of the PDPTRs rather than two, since architecturally
there is just one.
- Handle EXIT_FASTPATH_EXIT_USERSPACE in vendor code to ensure vendor code
gets a chance to handle things like reaping the PML buffer.
- Update KVM's view of PV async enabling if and only if the MSR write fully
succeeds.
- Fix a variety of issues where the emulator doesn't honor guest-debug state,
and clean up related code along the way.
- Synthesize EPT Violation and #NPF "error code" bits when injecting faults
into L1 that didn't originate in hardware (in which case the VMCS/VMCB
doesn't hold relevant information).
- Add support for virtualizing (well, emulating) AMD's flavor of CPL>0 CPUID
faulting.
- Clean up the GPR APIs so that KVM's use of "raw" is consistent, and fix a
variety of minor bugs along the way.
- Fix an OOB memory access due to not checking the VP ID when handling a
Hyper-V PV TLB flush for L2.
- Fix a bug in the mediated PMU's handling of fixed counters that allowed the
guest to bypass the PMU event filter.
- Allow userspace to return EAGAIN when handling SNP and TDX hypercalls, so
the KVM can forward a "retry" status code to the guest, and reserve all
unused error codes for future usage.
- Overhaul the TDP MMU => S-EPT code to move as much S-EPT specific logic as
possible into the TDX code, and to funnel (almost) all S-EPT updates into
a single chokepoint. The motivation is largely to prepare for upcoming
Dynamic PAMT support, but the cleanups are nice to have on their own.
- Plug a hole in shadow page table handling, where KVM fails to recursively
zap nested EPT/NPT shadow page tables when the nested hypervisor tears
down its own EPT/NPT page tables from the bottom up
x86 (Intel):
- Support for nested MBEC (Mode-Based Execute Control), see above in the
generic section; also run with MBEC enabled even for non-nested mode.
- Use the kernel's "enum pg_level" in the TDX APIs instead of the TDX-Module's
level definitions (which are 0-based).
- Rework the TDX memory APIs to not require/assume that guest memory is
backed by "struct page" (in prepartion for guest_memfd hugepage support).
- Fix a largely benign bug where KVM TDX would incorrectly state it could
emulate several x2APIC MSRs.
- Use the "safe" WRMSR API when proxying LBR MSR writes as the to-be-written
value is guest controlled and completely unvalidated.
x86 (AMD):
- Support for nested GMET (Guest Mode Execution Trap), see above in the
generic section; also run with GMET enabled even for non-nested mode.
- Fixes and minor cleanups to GHCB handling, on top of the earlier work
already merged into 7.1-rc.
- Ensure KVM's copy of CR0 and CR3 are up-to-date prior to invoking
fastpath handlers.
- Add support for virtualizing gPAT (KVM previously just used L1's PAT when
running L2).
- Fix goofs where KVM mishandles side effects (e.g. single-step and PMC
updates) when emulating VMRUN.
- Fix a variety of bugs in AVIC's handling of x2APIC MSR interception, most
notably where KVM didn't disable interception of IRR, ISR, and TMR regs.
- Add support for virtualizing Host-Only/Guest-Only bits in the mediated PMU.
- Don't advertise support for unusable VM types, and account for VM types
that are disabled by firmware, e.g. to mitigate security vulnerabilities.
- Rewrite the SEV {en,de}crypt debug ioctls as they were riddle with bugs and
unnecessarily complicated, and add comprehensive tests.
- Clean up and deduplicate the SEV page pinning code.
- Fix minor goofs related to writing back CPUID information after firmware
rejects a CPUID page for an SNP vCPU.
Generic:
- Rename invalidate_begin() to invalidate_start() throughout KVM to follow
the kernel's nomenclature, e.g. for mmu_notifiers.
- Use guard() to cleanup up various KVM+VFIO flows.
- Minor cleanups.
guest_memfd:
- Return -EEXIST instead of -EINVAL if userspace attempts to bind a gmem
range to multiple memslots, and fix the test that was supposed to ensure
KVM returns -EEXIST.
- Treat memslot binding offsets and sizes as unsigned values to fix a bug
where KVM interprets a large "offset + size" as a negative value and allows
a nonsensical offset.
- Use the inode number instead of the page offset for the NUMA interleaving
index to fix a bug where the effective index would jump by two for
consecutive pages (the caller also adds in the page offset).
Selftests:
- Randomize the dirty log test's delay when reaping the bitmap on the first
pass, as always waiting only 1ms hid a KVM RISC-V bug as the test reaped the
bitmap before KVM could build up enough state to hit the bug.
- A pile of one-off fixes and cleanups.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm updates from Paolo Bonzini:
"arm64:
This is a bit of an odd merge window on the KVM/arm64 front. There
is absolutely no new feature in the pull request. It is purely
fixes, because it is simply becoming too hard to review new stuff
when so many AI-fuelled fixes hit the list.
- Significant cleanup of the vgic-v5 PPI support which was merged in
7.1. This makes the code more maintainable, and squashes a couple
of bugs in the meantime
- Set of fixes for the handling of the MMU in an NV context,
particularly VNCR-triggered faults. S1POE support is fixed as well
- Large set of pKVM fixes, mostly addressing recurring issues around
hypervisor tracking of donated pages in obscure cases where the
donation could fail and leave things in a bizarre state
- Fixes for the so-called "lazy vgic init", which resulted in
sleeping operations in non-preemptible sections. This turned out to
be far more invasive than initially expected..
- Reduce the overhead of L1/L2 context switch by not touching the FP
registers
- Fix the way non-implemented page sizes are dealt with when a guest
insist on using them for S2 translation
- The usual set of low-impact fixes and cleanups all over the map
Loongarch:
- On a request for lazy FPU load, load all FPU state that the VM
supports instead of enabling only the part (FPU, LSX or LASX) that
caused the FPU load request
- Some enhancements about interrupt injection
- Some bug fixes and other small changes
RISC-V:
- Batch G-stage TLB flushes for GPA range based page table updates
- Convert HGEI line management to fully per-HART
- Fix missing CSR dirty marking when FWFT state updated via ONE_REG
- Fix stale FWFT feature exposure to Guest/VM
- Speed up dirty logging write faults using MMU rwlock and atomic PTE
updates using cmpxchg() for permission-only changes
- Use flexible array for APLIC IRQ state
- Use kvm_slot_dirty_track_enabled() for logging enable check on a
memslot
- Avoid skipping valid pages in kvm_riscv_gstage_wp_range()
- Avoid skipping valid pages in kvm_riscv_gstage_unmap_range()
- Use endian-specific __lelong for NACL shared memory
S390:
- KVM_PRE_FAULT_MEMORY support
- Support for 2G hugepages
- Support for the ASTFLEIE 2 facility
- Support for fast inject using kvm_arch_set_irq_inatomic
- Fix potential leak of uninitialized bytes
- A few more misc gmap fixes
x86:
- Generic support for the more granular permissions allowed by EPT,
namely "read" (which was previously usurping the U bit) and
separate execution bits for kernel and userspace
- Do not assume that all page tables start with U=1/W=1/NX=0 at the
root, as AMD GMET needs to have U=0 at the root
- Introduce common assembly macros for use within Intel and AMD
vendor-specific vmentry code. This touches the SPEC_CTRL handling,
which is now entirely done in assembly for Intel (by reusing the
AMD code that already existed), and register save/restore which
uses some macro magic to compute the offsets in the struct. Both of
these are preparatory changes for upcoming APX support
- Clean up KVM's register tracking and storage, primarily to prepare
for APX support, which expands the maximum number of GPRs from 16
to 32
- Keep a single copy of the PDPTRs rather than two, since
architecturally there is just one
- Handle EXIT_FASTPATH_EXIT_USERSPACE in vendor code to ensure vendor
code gets a chance to handle things like reaping the PML buffer
- Update KVM's view of PV async enabling if and only if the MSR write
fully succeeds
- Fix a variety of issues where the emulator doesn't honor
guest-debug state, and clean up related code along the way
- Synthesize EPT Violation and #NPF "error code" bits when injecting
faults into L1 that didn't originate in hardware (in which case the
VMCS/VMCB doesn't hold relevant information)
- Add support for virtualizing (well, emulating) AMD's flavor of
CPL>0 CPUID faulting
- Clean up the GPR APIs so that KVM's use of "raw" is consistent, and
fix a variety of minor bugs along the way
- Fix an OOB memory access due to not checking the VP ID when
handling a Hyper-V PV TLB flush for L2
- Fix a bug in the mediated PMU's handling of fixed counters that
allowed the guest to bypass the PMU event filter
- Allow userspace to return EAGAIN when handling SNP and TDX
hypercalls, so the KVM can forward a "retry" status code to the
guest, and reserve all unused error codes for future usage
- Overhaul the TDP MMU => S-EPT code to move as much S-EPT specific
logic as possible into the TDX code, and to funnel (almost) all
S-EPT updates into a single chokepoint. The motivation is largely
to prepare for upcoming Dynamic PAMT support, but the cleanups are
nice to have on their own
- Plug a hole in shadow page table handling, where KVM fails to
recursively zap nested EPT/NPT shadow page tables when the nested
hypervisor tears down its own EPT/NPT page tables from the bottom
up
x86 (Intel):
- Support for nested MBEC (Mode-Based Execute Control), see above in
the generic section; also run with MBEC enabled even for non-nested
mode
- Use the kernel's "enum pg_level" in the TDX APIs instead of the
TDX-Module's level definitions (which are 0-based)
- Rework the TDX memory APIs to not require/assume that guest memory
is backed by "struct page" (in prepartion for guest_memfd hugepage
support)
- Fix a largely benign bug where KVM TDX would incorrectly state it
could emulate several x2APIC MSRs
- Use the "safe" WRMSR API when proxying LBR MSR writes as the
to-be-written value is guest controlled and completely unvalidated
x86 (AMD):
- Support for nested GMET (Guest Mode Execution Trap), see above in
the generic section; also run with GMET enabled even for non-nested
mode
- Fixes and minor cleanups to GHCB handling, on top of the earlier
work already merged into 7.1-rc
- Ensure KVM's copy of CR0 and CR3 are up-to-date prior to invoking
fastpath handlers
- Add support for virtualizing gPAT (KVM previously just used L1's
PAT when running L2)
- Fix goofs where KVM mishandles side effects (e.g. single-step and
PMC updates) when emulating VMRUN
- Fix a variety of bugs in AVIC's handling of x2APIC MSR
interception, most notably where KVM didn't disable interception of
IRR, ISR, and TMR regs
- Add support for virtualizing Host-Only/Guest-Only bits in the
mediated PMU
- Don't advertise support for unusable VM types, and account for VM
types that are disabled by firmware, e.g. to mitigate security
vulnerabilities
- Rewrite the SEV {en,de}crypt debug ioctls as they were riddle with
bugs and unnecessarily complicated, and add comprehensive tests
- Clean up and deduplicate the SEV page pinning code
- Fix minor goofs related to writing back CPUID information after
firmware rejects a CPUID page for an SNP vCPU
Generic:
- Rename invalidate_begin() to invalidate_start() throughout KVM to
follow the kernel's nomenclature, e.g. for mmu_notifiers
- Use guard() to cleanup up various KVM+VFIO flows
- Minor cleanups
guest_memfd:
- Return -EEXIST instead of -EINVAL if userspace attempts to bind a
gmem range to multiple memslots, and fix the test that was supposed
to ensure KVM returns -EEXIST
- Treat memslot binding offsets and sizes as unsigned values to fix a
bug where KVM interprets a large "offset + size" as a negative
value and allows a nonsensical offset
- Use the inode number instead of the page offset for the NUMA
interleaving index to fix a bug where the effective index would
jump by two for consecutive pages (the caller also adds in the page
offset)
Selftests:
- Randomize the dirty log test's delay when reaping the bitmap on the
first pass, as always waiting only 1ms hid a KVM RISC-V bug as the
test reaped the bitmap before KVM could build up enough state to
hit the bug
- A pile of one-off fixes and cleanups"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (326 commits)
KVM: x86/mmu: Ensure hugepage is in by slot before checking max mapping level
KVM: x86: Fix shadow paging use-after-free due to unexpected role
KVM: s390: Introducing kvm_arch_set_irq_inatomic fast inject
KVM: s390: Enable adapter_indicators_set to use mapped pages
KVM: s390: Add map/unmap ioctl and clean mappings post-guest
riscv: kvm: Use endian-specific __lelong for NACL shared memory
KVM: selftests: access_tracking_perf_test: bump number of NUMA nodes to 32
KVM: s390: vsie: Implement ASTFLEIE facility 2
KVM: s390: vsie: Refactor handle_stfle
s390/sclp: Detect ASTFLEIE 2 facility
KVM: s390: Minor refactor of base/ext facility lists
KVM: x86/mmu: move pdptrs out of the MMU
KVM: x86: check that kvm_handle_invpcid is only invoked with shadow paging
KVM: nSVM: invalidate cached PDPTRs across nested NPT transitions
KVM: nVMX: remove unnecessary code in prepare_vmcs02_rare
KVM: x86: remove nested_mmu from mmu_is_nested()
KVM: arm64: vgic-its: Make ABI commit helpers return void
KVM: s390: Initialize KVM_S390_GET_CMMA_BITS memory
LoongArch: KVM: Add missing slots_lock for device register/unregister
LoongArch: KVM: Validate irqchip index in irqfd routing
...
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>
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>
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>
CPU errata handling:
- Extend CnP disabling workaround to HiSilicon HIP09 hardware.
- Work around eternally broken broadcast TLB invalidation on more CPUs.
- Documentation and code cleanups.
CPU features:
- Add new hwcaps for the 2025 dpISA extensions.
Floating point / SVE / SME:
- Significant cleanup to the low-level state management code in the core
architecture code and KVM.
- Use correct register widths during SVE/SME save/restore assembly.
- Expose SVE/SME save/restore memory accesses to sanitisers.
Memory management:
- Preparatory work for unmapping the kernel data and bss sections from
the linear map.
Miscellaneous:
- Inline DAIF manipulation helpers so they can be used safely from
non-instrumentable code.
- Fix handling of the 'nosmp' cmdline option to avoid marking secondary
cores as "possible".
MPAM:
- Add support for v0.1 of the MPAM architecture.
Perf:
- Update HiSilicon PMU MAINTAINERS entry.
- Fix event encodings for the DVM node in the CMN driver.
Selftests:
- Extend sigframe tests to cover POE context.
- Add coverage for the newly added 2025 dpISA hwcaps.
System registers:
- Add new registers and ESR encodings for the HDBSS feature.
Plus minor fixes and cleanups across the board.
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Merge tag 'arm64-upstream' of gitolite.kernel.org:pub/scm/linux/kernel/git/arm64/linux
Pull arm64 updates from Will Deacon:
"It feels like the new world of AI tooling has slowed us down a little
on the feature side when compared to the fixes side. The extra rounds
of Sashiko review have also pushed a few things out until next time.
Still, there's some good foundational stuff here for the fpsimd code
and hardening work towards removing the predictable linear alias of
the kernel image.
CPU errata handling:
- Extend CnP disabling workaround to HiSilicon HIP09 hardware.
- Work around eternally broken broadcast TLB invalidation on more
CPUs.
- Documentation and code cleanups.
CPU features:
- Add new hwcaps for the 2025 dpISA extensions.
Floating point / SVE / SME:
- Significant cleanup to the low-level state management code in the
core architecture code and KVM.
- Use correct register widths during SVE/SME save/restore assembly.
- Expose SVE/SME save/restore memory accesses to sanitisers.
Memory management:
- Preparatory work for unmapping the kernel data and bss sections
from the linear map.
Miscellaneous:
- Inline DAIF manipulation helpers so they can be used safely from
non-instrumentable code.
- Fix handling of the 'nosmp' cmdline option to avoid marking
secondary cores as "possible".
MPAM:
- Add support for v0.1 of the MPAM architecture.
Perf:
- Update HiSilicon PMU MAINTAINERS entry.
- Fix event encodings for the DVM node in the CMN driver.
Selftests:
- Extend sigframe tests to cover POE context.
- Add coverage for the newly added 2025 dpISA hwcaps.
System registers:
- Add new registers and ESR encodings for the HDBSS feature.
Plus minor fixes and cleanups across the board"
* tag 'arm64-upstream' of gitolite.kernel.org:pub/scm/linux/kernel/git/arm64/linux: (73 commits)
arm64: errata: Mitigate TLBI errata on Microsoft Azure Cobalt 100 CPU
arm64: errata: Mitigate TLBI errata on NVIDIA Olympus CPU
arm64: errata: Mitigate TLBI errata on various Arm CPUs
arm64: cputype: Add C1-Premium definitions
arm64: cputype: Add C1-Ultra definitions
Revert "arm64: mm: Unmap kernel data/bss entirely from the linear map"
Revert "arm64: mm: Defer remap of linear alias of data/bss"
arm64: arch_timer: reuse arch_timer_read_cnt{p,v}ct_el0() helpers
arm64/mm: Rename ptdesc_t
arm64: mm: Defer remap of linear alias of data/bss
KVM: arm64: Omit tag sync on stage-2 mappings of the zero page
arm64: Avoid double evaluation of __ptep_get()
kasan: Move generic KASAN page tables out of BSS too
arm64: Rename page table BSS section to .bss..pgtbl
arm64: patching: replace min_t with min in __text_poke
perf/arm-cmn: Fix DVM node events
arm64: fpsimd: Remove <asm/fpsimdmacros.h>
arm64: fpsimd: Move SME save/restore inline
arm64: fpsimd: Move sve_flush_live() inline
arm64: fpsimd: Move SVE save/restore inline
...
* New features:
- None. Zilch. Nada. Que dalle.
* Fixes and other improvements:
- Significant cleanup of the vgic-v5 PPI support which was merged in
7.1. This makes the code more maintainable, and squashes a couple
of bugs in the meantime.
- Set of fixes for the handling of the MMU in an NV context,
particularly VNCR-triggered faults. S1POE support is fixed
as well.
- Large set of pKVM fixes, mostly addressing recurring issues
around hypervisor tracking of donated pages in obscure cases
where the donation could fail and leave things in a bizarre
state.
- Fixes for the so-called "lazy vgic init", which resulted in
sleeping operations in non-preemptible sections. This turned
out to be far more invasive than initially expected...
- Reduce the overhead of L1/L2 context switch by not touching
the FP registers.
- Fix the way non-implemented page sizes are dealt with when
a guest insist on using them for S2 translation.
- The usual set of low-impact fixes and cleanups all over the map.
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Merge tag 'kvmarm-7.2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm64 updates for 7.2
* New features:
- None. Zilch. Nada. Que dalle.
* Fixes and other improvements:
- Significant cleanup of the vgic-v5 PPI support which was merged in
7.1. This makes the code more maintainable, and squashes a couple
of bugs in the meantime.
- Set of fixes for the handling of the MMU in an NV context,
particularly VNCR-triggered faults. S1POE support is fixed
as well.
- Large set of pKVM fixes, mostly addressing recurring issues
around hypervisor tracking of donated pages in obscure cases
where the donation could fail and leave things in a bizarre
state.
- Fixes for the so-called "lazy vgic init", which resulted in
sleeping operations in non-preemptible sections. This turned
out to be far more invasive than initially expected...
- Reduce the overhead of L1/L2 context switch by not touching
the FP registers.
- Fix the way non-implemented page sizes are dealt with when
a guest insist on using them for S2 translation.
- The usual set of low-impact fixes and cleanups all over the map.
* 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>
* 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>
* 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>
* 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>
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>
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>
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>
KVM invalidates the I-cache before installing an executable PTE on
implementations without DIC. Unfortunately, support for FEAT_XNX
broke this check as KVM_PTE_LEAF_ATTR_HI_S2_XN was expanded to a
bitfield.
Fix it by reusing kvm_pgtable_stage2_pte_prot() and testing the abstract
permission bits instead.
Fixes: 2608563b46 ("KVM: arm64: Add support for FEAT_XNX stage-2 permissions")
Reported-by: Sashiko (gemini/gemini-3.1-pro-preview)
Signed-off-by: Oliver Upton <oupton@kernel.org>
Reviewed-by: Wei-Lin Chang <weilin.chang@arm.com>
Link: https://patch.msgid.link/20260602165901.52800-3-oupton@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
We propagate CPTR_EL2.E0POE from a L1 into the L0 configuration, but
we key this on the L1 guest supporting FEAT_S2POE. This is obviously
wrong, as this bit is solely concerned with Stage-1 translation.
Fix this by making the update depend on FEAT_S1POE.
Fixes: cd931bd609 ("KVM: arm64: nv: Add additional trap setup for CPTR_EL2")
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Reviewed-by: Oliver Upton <oupton@kernel.org>
Link: https://patch.msgid.link/20260602155430.2088142-2-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
Currently the SVE register save/restore sequences are written in
out-of-line assembly routines. While this works, it's somewhat painful:
* As KVM needs to be able to use the sequences in hyp code, separate
assembly files are used for the regular kernel and KVM code. While the
common logic is shared in assembly macros, this still requires some
duplication, and has lead to some trivial divergence.
* As the SVE LDR/STR instrucitons have limited addressing modes, the
assembly macros use an awkward pattern requiring negative offsets.
This could be written more clearly with addresses being generated in C
code.
* As the FFR does not always exist in streaming mode, some awkward
conditional branching has been written in assembly which could be
clearer in C (and would permit the compiler to optimize out
unnecessary branches in some cases).
* For historical reasons, the assembly macros take some register
arguments as numerical indices (e.g. "sve_save 0, x1" uses x0 and x1),
which is simply confusing.
* For historical reasons, the SVE save/restore code and FPSIMD
save/restore code have a distinct sequences for FPSR and FPCR. Ideally
this logic would be shared.
* The assembly sequences can't be instrumented, and so it's harder than
necessary to catch memory safety issues.
To handle the above, move the SVE register save/restore sequences
to inline assembly.
Neither GCC nor LLVM instrument memory arguments to inline assembly, so
explicit instrumentation is added in the same manner as other assembly
routines. This instrumentation is implicitly disabled by Kbuild for nVHE
hyp code.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Fuad Tabba <tabba@google.com>
Cc: James Morse <james.morse@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Oliver Upton <oupton@kernel.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
As the SVE state size can vary at runtime, we don't have a concrete type
for the in-memory SVE state, and pass this around using a pointer to
void. The functions which save/restore the SVE state have a very unusual
calling convention, expecting a pointer to the FFR *in the middle of*
the in-memory SVE state, which is also passed as a pointer to void.
Passing a pointer to the FFR also requires that callers find the live VL
and perform some arithmetic, which callers implement differently.
Using pointer to void means that it's very easy to introduce errors that
cannot be caught by the compiler (e.g. as 'void **' can be assigned to
'void *'). In general this is unnecessarily confusing and fragile.
Improve this by adding an opaque 'struct arm64_sve_state', and
consistently passing a pointer to this, performing the necessary
offsetting *within* the save/restore functions.
For the moment, the offsetting is performed in a new '_sve_pffr'
assembly macro, using the ADDVL and ADDPL instructions. These add a
multiple of the live vector length and predicate length respectively.
The ADDVL immediate range cannot encode 32, so this is split into two
increments of 16.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Fuad Tabba <tabba@google.com>
Cc: James Morse <james.morse@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Oliver Upton <oupton@kernel.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
Currently the FPSIMD register save/restore sequences are written in
out-of-line assembly routines. While this works, it's somewhat painful:
* As KVM needs to be able to use the sequences in hyp code, separate
assembly files are used for the regular kernel and KVM code. While the
common logic is shared in assembly macros, this still requires some
duplication, and has lead to some trivial divergence.
* For historical reasons, the assembly macros take some register
arguments as numerical indices (e.g. "fpsimd_save x0, 8" uses x0 and
x8), which is simply confusing.
* For historical reasons, the SVE save/restore code and FPSIMD
save/restore code have distinct sequences for FPSR and FPCR. Ideally
this logic would be shared.
* The assembly sequences can't be instrumented, and so it's harder than
necessary to catch memory safety issues.
To handle the above, move the FPSIMD register save/restore sequences to
inline assembly, and share the FPSR+FPCR save/restore with SVE.
Neither GCC nor LLVM instrument memory arguments to inline assembly, so
explicit instrumentation is added in the same manner as other assembly
routines. This instrumentation is implicitly disabled by Kbuild for nVHE
hyp code.
I've used the SVE sequence for restoring FPCR, which uses an
unconditional write to FPCR, rather than the conditional write used by
the FPSIMD assembly sequence. I believe that in practice, this doesn't
matter to a real workload, and given it's possible for the mis-predicted
branch to cost more than the necessary micro-architectural
synchronization, I strongly suspect any performance impact is within the
noise.
Looking at the history, the FPSIMD assembly sequence was changed to use
a conditional write to FPCR since 2014 in commit:
5959e25729 ("arm64: fpsimd: avoid restoring fpcr if the contents haven't change")
... as described in the commit message, this was based on an expectation
of implementation style, and was not based on benchmarking.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Fuad Tabba <tabba@google.com>
Cc: James Morse <james.morse@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Oliver Upton <oupton@kernel.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
Regardless of whether the vector registers are saved in FPSIMD or SVE
format, we store FPSR and FPCR in user_fpsimd_state::{fpsr,fpcr}.
For historical reasons, the functions which save/restore SVE context
take a pointer to user_fpsimd_state::fpsr, and use this to access both
user_fpsimd_state::fpsr and user_fpsimd_state::fpcr. This is
unnecessarily fragile.
Move the save/restore of FPSR and FPCR into separate helper functions
which take a pointer to user_fpsimd_state. I've used read_sysreg_s() and
write_sysreg_s() as contemporary versions of LLVM will refuse to
directly assemble accesses to FPCR or FPSR unless the "fp" arch
extension is enabled.
For the moment, fpsimd_save_state() and fpsimd_load_state() are left
as-is with their own logic to save/restore FPSR and FPCR. This will be
unified in subsequent patches.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Fuad Tabba <tabba@google.com>
Cc: James Morse <james.morse@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Oliver Upton <oupton@kernel.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
There's no need for struct cpu_sve_state. Code would be simpler and more
robust without it, and removing it will simplify further cleanups (e.g.
adding an opaque type for the sve register state).
Protected KVM stores most of the host's system register state in
kvm_host_data::host_ctxt, which is an instance of struct
kvm_cpu_context. As kvm_cpu_context::sys_regs[] has a slot for ZCR_EL1,
we can store the host's ZCR_EL1 there.
While kvm_cpu_context::sys_regs doesn't have slots for FPSR and FPCR,
these are usually expected to be stored in struct user_fpsimd_state.
For historical reasons, __sve_save_state and __sve_restore_state()
expect a pointer to fpsr *within* struct user_fpsimd_state, assuming the
fpcr will immediately follow, as per the order within struct
user_fpsimd_state. We currently match this ordering in struct
cpu_sve_state, but it would be simpler and more robust to use struct
user_fpsimd_state directly.
After moving ZCR_EL1, FPSR, and FPCR out of struct cpu_sve_state, all
that's left is sve_regs, which can be represented as a pointer without
need for a container struct. This is kept as a pointer to u8 (matching
the array type), as this permits the compiler to catch unbalanced
referencing/dereferencing, which is not possible for pointers to void.
Apply the above changes, and remove cpu_sve_state.
I've dropped the comment regarding buffer alignment as AFAICT this was
never necessary. The LDR/STR (vector) instructions only require this
alignment when SCTLR_ELx.A==1, which is not the case for the kernel or
hyp code. Nothing else depends on the alignment.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Fuad Tabba <tabba@google.com>
Cc: James Morse <james.morse@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Oliver Upton <oupton@kernel.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
Protected KVM stores most of the host's system register state in
kvm_host_data::host_ctxt, which is an instance of struct
kvm_cpu_context. As kvm_cpu_context::sys_regs[] has a slot for FPMR, we
can store the host's FPMR there.
Do so, and remove kvm_host_data::fpmr.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Fuad Tabba <tabba@google.com>
Cc: James Morse <james.morse@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Oliver Upton <oupton@kernel.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
The __sve_save_state() and __sve_restore_state() functions take a
parameter describing whether to save/restore the FFR, but both functions
silently override this with '1'. This has always been benign (and
callers have all passed 'true' since the parameter was introduced), but
clearly this is not intentional.
Historically, the functions always saved/restored the FFR, and there was
no parameter to control this.
In v5.16, the sve_save and sve_load assembly macros used by
__sve_save_state() and __sve_restore_state() were changed to make
saving/restoring FFR optional. The implementations of __sve_save_state()
and __sve_restore_state() were changed to pass '1' to their respective
macros, and the prototypes of __sve_save_state() and
__sve_restore_state() were unchanged. See commit:
9f58486657 ("arm64/sve: Make access to FFR optional")
In v6.10, the prototypes of __sve_save_state() and __sve_restore_state()
were changed to add 'save_ffr' and 'restore_ffr' parameters
respectively, but the implementations were not changed to stop passing 1
to their respective macros. All callers were changed to pass 'true' to
__sve_save_state() and __sve_restore_state(). See commit:
45f4ea9bcf ("KVM: arm64: Fix prototype for __sve_save_state/__sve_restore_state")
This is all benign, but clearly unintentional, and it gets in the way of
cleaning up the FPSIMD/SVE/SME code. Remove the unnecessary overriding.
The 'save_ffr' and 'restore_ffr' parameters are 32-bit ints, and per the
AAPCS64 parameter passing rules, the upper 32 bits of the register
holding these arguments might contain arbitrary values. Thus it is
necessary to pass 'w2' rather than 'x2' to the sve_load and save_save
macros, such that the upper 32 bits are ignored when deciding whether to
save/restore the FFR.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Fuad Tabba <tabba@google.com>
Cc: James Morse <james.morse@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Oliver Upton <oupton@kernel.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
There's no need for hyp/entry.S to include <asm/fpsimdmacros.h>.
The fpsimd macros have never been used by code in hyp/entry.S, and were
instead used by code in hyp/fpsimd.S.
Remove the unnecessary include.
There should be no functional change as a result of this patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Fuad Tabba <tabba@google.com>
Cc: James Morse <james.morse@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Oliver Upton <oupton@kernel.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
ZCR_EL2 can be updated by a VHE guest hypervisor either using ZCR_EL2
(which traps) or ZCR_EL1 (which does not trap). KVM handles both in
different way:
- on ZCR_EL2 trap, ZCR_EL2.LEN is immediately capped at the VM's own
VL limit. This has the potential to break existing SW that relies
on the full LEN field to be stateful.
- on ZCR_EL1 access, we do absolutely nothing.
On restoring the SVE context for an L2 guest, we directly restore the
guest hypervisor's view of ZCR_EL2 into the physical ZCR_EL2. If the
guest's view of the register was updated using the ZCR_EL2 accessor,
the value has already been sanitised (with the caveat mentioned above).
But if the guest used ZCR_EL1, the raw value is written into the HW,
and the L2 guest can now access VLs that it shouldn't.
Fix all the above by moving the VL capping to the restore points,
ensuring that:
- the HW is always programmed with a capped value, irrespective of
the accessor being used,
- the ZCR_EL2.LEN field is always completely stateful, irrespective
of the accessor being used.
Additionally, move ZCR_EL2 to be a sanitised register, ensuring that
only the LEN field is actually stateful. This requires some creative
construction of the RES0 mask, as the sysreg generation script does
not yet generate RAZ/WI fields.
Fixes: b3d29a8230 ("KVM: arm64: nv: Handle ZCR_EL2 traps")
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260529-kvm-arm64-fix-zcr-len-nv-v2-1-86cad51992bd@kernel.org
[maz: rewrote commit message, tidy up access_zcr_el2()]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Since commit fe49fd940e ("KVM: arm64: Move VTCR_EL2 into struct s2_mmu"),
@arch is no longer required to obtain the per-kvm_s2_mmu vtcr and can be
removed from __load_stage2().
Signed-off-by: Zenghui Yu (Huawei) <zenghui.yu@linux.dev>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://patch.msgid.link/20260318144305.56831-1-zenghui.yu@linux.dev
Signed-off-by: Marc Zyngier <maz@kernel.org>
__pkvm_host_donate_guest() flips the host stage-2 PTE for the
donated page to a non-valid annotation via
host_stage2_set_owner_metadata_locked() and then calls
kvm_pgtable_stage2_map() to install the matching guest stage-2
mapping. The map's return value is wrapped in WARN_ON() and
otherwise discarded, asserting that the call cannot fail.
WARN_ON() at nVHE EL2 panics, so this assertion is only correct
if the call genuinely cannot fail. kvm_pgtable_stage2_map() can
fail with -ENOMEM even at PAGE_SIZE granularity: the donate path
verifies PKVM_NOPAGE for the guest IPA before the map, so the
walker must allocate fresh page-table pages from the vcpu
memcache, and the host controls the vcpu memcache via the topup
interface. An under-provisioned donation request would otherwise
turn a recoverable -ENOMEM into a fatal hyp panic.
Bound the worst-case walker allocation alongside the existing
__host_check_page_state_range() / __guest_check_page_state_range()
pre-checks, using the helper introduced for host->guest share. If
the vcpu memcache holds fewer pages than kvm_mmu_cache_min_pages(),
return -ENOMEM before any state mutation.
Fixes: 1e579adca1 ("KVM: arm64: Introduce __pkvm_host_donate_guest()")
Assisted-by: Gemini:gemini-3.1-pro review-prompts
Signed-off-by: Fuad Tabba <tabba@google.com>
Link: https://patch.msgid.link/20260501112149.2824881-7-tabba@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
__pkvm_host_share_guest() ends with kvm_pgtable_stage2_map() to
install the guest stage-2 mapping, after a forward pass that mutates
the host vmemmap (sets PKVM_PAGE_SHARED_OWNED and increments
host_share_guest_count) for every page in the range. The map's
return value is wrapped in WARN_ON() and otherwise discarded,
asserting that the call cannot fail.
WARN_ON() at nVHE EL2 panics, so this assertion is only correct if
the call genuinely cannot fail. kvm_pgtable_stage2_map() can fail
with -ENOMEM when the stage-2 walker exhausts the caller's
memcache, and the host controls the vcpu memcache via the topup
interface, so an under-provisioned share request would otherwise
turn a recoverable -ENOMEM into a fatal hyp panic.
Bound the worst-case walker allocation in the existing pre-check
pass so that kvm_pgtable_stage2_map() cannot fail at the call
site, using kvm_mmu_cache_min_pages() -- the same bound host EL1
uses for its own stage-2 maps. If the vcpu memcache holds fewer
pages, return -ENOMEM before any state mutation.
Fixes: d0bd3e6570 ("KVM: arm64: Introduce __pkvm_host_share_guest()")
Assisted-by: Gemini:gemini-3.1-pro review-prompts
Signed-off-by: Fuad Tabba <tabba@google.com>
Link: https://patch.msgid.link/20260501112149.2824881-6-tabba@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
The hypercall handlers call pkvm_refill_memcache() to top up the
hyp_vcpu memcache before invoking __pkvm_host_{share,donate}_guest().
pkvm_ownership_selftest invokes those functions directly with a
static selftest_vcpu that has an empty memcache.
Seed selftest_vcpu's memcache from the prepopulated selftest
pages, leaving the remainder for selftest_vm.pool. Required by
the memcache-sufficiency pre-check added in the following
patches.
Assisted-by: Gemini:gemini-3.1-pro review-prompts
Signed-off-by: Fuad Tabba <tabba@google.com>
Link: https://patch.msgid.link/20260501112149.2824881-5-tabba@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
__deactivate_fgt() declares its first parameter as "htcxt" but the body
references "hctxt". The parameter is unused; the macro silently captures
"hctxt" from the enclosing scope. Both existing callers
(__deactivate_traps_hfgxtr() and __deactivate_traps_ich_hfgxtr()) happen
to define a local "struct kvm_cpu_context *hctxt", so the macro works
by coincidence.
A future caller without an "hctxt" local in scope, or naming it
differently, would compile but bind to the wrong context. Align the
parameter name with the sibling __activate_fgt() macro.
The "vcpu" parameter remains unused in the body, kept for API symmetry
with __activate_fgt() (which uses it).
Fixes: f5a5a406b4 ("KVM: arm64: Propagate and handle Fine-Grained UNDEF bits")
Assisted-by: Gemini:gemini-3.1-pro review-prompts
Signed-off-by: Fuad Tabba <tabba@google.com>
Link: https://patch.msgid.link/20260501112149.2824881-4-tabba@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
On VHE, __hyp_call_panic() unconditionally calls __deactivate_traps(vcpu)
on the vcpu pointer read from host_ctxt->__hyp_running_vcpu. That pointer
is cleared after every guest exit (and is never set when no guest is
running), so an unexpected EL2 exception landing in _guest_exit_panic,
e.g. via the el2t*_invalid / el2h_irq_invalid vectors - reaches this
function with vcpu == NULL. __deactivate_traps() then dereferences vcpu
via ___deactivate_traps() -> vserror_state_is_nested() -> vcpu_has_nv()
-> vcpu->arch.features, faulting inside the panic handler and obscuring
the original failure.
The nVHE counterpart (hyp_panic() in arch/arm64/kvm/hyp/nvhe/switch.c)
already guards its vcpu-using cleanup with "if (vcpu)"; mirror that
here. sysreg_restore_host_state_vhe() does not depend on vcpu and
continues to run unconditionally, preserving panic forensics. The
trailing panic("...VCPU:%p", vcpu) prints "(null)" safely via printk's
%p handling.
Fixes: 6a0259ed29 ("KVM: arm64: Remove hyp_panic arguments")
Assisted-by: Gemini:gemini-3.1-pro review-prompts
Signed-off-by: Fuad Tabba <tabba@google.com>
Link: https://patch.msgid.link/20260501112149.2824881-3-tabba@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
A previous bug in __pkvm_init_vm error path showed that the hypervisor
could leak refcounted pages, (i.e. losing access to a page while its
refcount is still elevated). This poses a threat to the pKVM state
machine.
Address this by introducing a fail-safe in __pkvm_hyp_donate_host.
Transitions are not a hot path so added security is worth the extra
check.
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Link: https://patch.msgid.link/20260521143626.1005660-4-vdonnefort@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
In the unlikely case where insert_vm_table_entry fails, __pkvm_init_vm
release the memory donated by the host for the PGD, but as the stage-2
is still set-up the hypervisor keeps a refcount on those pages,
effectively leaking the references.
Fix the rollback with the newly added kvm_guest_destroy_stage2().
Fixes: 256b4668cd ("KVM: arm64: Introduce separate hypercalls for pKVM VM reservation and initialization")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Link: https://patch.msgid.link/20260521143626.1005660-3-vdonnefort@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
When a VM fails to initialise after its stage-2 hyp_pool has been
initialised, that stage-2 must be torn down entirely. This requires
resetting both the refcount and the order of its pages back to 0.
Currently, reclaim_pgtable_pages() implicitly resets the page order by
allocating the entire pool with order-0 granularity. However, in the VM
initialisation error path, the addresses of the donated memory (the PGD)
are already known, making it unnecessary to iterate over all pages in
the pool.
Since the vmemmap page order is a hyp_pool-specific field, leaving a
non-zero order on hyp_pool destruction is harmless until another pool
attempts to admit the page. Instead of resetting this field during
destruction, reset it during pool initialization in hyp_pool_init().
For 'external' pages, we can't trust the order either as they bypass
hyp_pool_init(). Since we never coalesce them, enforce order-0 to ensure
safe insertion into the pool.
This leaves no vmemmap order users outside of hyp_pool.
Fixes: 256b4668cd ("KVM: arm64: Introduce separate hypercalls for pKVM VM reservation and initialization")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Link: https://patch.msgid.link/20260521143626.1005660-2-vdonnefort@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
Although we have some code supporting 128 PPIs, the only supported
configuration is 64 PPIs. There is no way to test the 128 PPI code,
so it is bound to bitrot very quickly.
Given that KVM/arm64's goal has always been to stick to non-IMPDEF
behaviours, drop the 128 PPI support. Someone motivated enough and
with very strong arguments can always bring it back -- it's all in
the git history.
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Link: https://lore.kernel.org/r/20260520091949.542365-10-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
A typo in the config guard in __hyp_do_panic broke the stage-2 disabling
and made backtraces for pKVM quite unreliable.
Fix that typo.
Fixes: 9019e82c7e ("KVM: arm64: Add PKVM_DISABLE_STAGE2_ON_PANIC")
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Link: https://patch.msgid.link/20260520220830.273289-1-vdonnefort@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
pKVM must validate the host-provided tracing buffer descriptor.
However, if an error is found, the hypervisor would just return 0 to the
host. Fix the return value on validation failure.
While at it, rename the function to hyp_trace_desc_is_valid() and skip
validation for the nVHE mode as we trust host-provided data in that
case.
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Fixes: 680a04c333 ("KVM: arm64: Add tracing capability for the nVHE/pKVM hyp")
Link: https://lore.kernel.org/r/20260514162624.3477857-1-vdonnefort@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
__pkvm_host_donate_guest() flips the host stage-2 PTE for the
donated page to a non-valid annotation via
host_stage2_set_owner_metadata_locked() and then calls
kvm_pgtable_stage2_map() to install the matching guest stage-2
mapping. The map's return value is wrapped in WARN_ON() and
otherwise discarded, asserting that the call cannot fail.
WARN_ON() at nVHE EL2 panics, so this assertion is only correct
if the call genuinely cannot fail. kvm_pgtable_stage2_map() can
fail with -ENOMEM even at PAGE_SIZE granularity: the donate path
verifies PKVM_NOPAGE for the guest IPA before the map, so the
walker must allocate fresh page-table pages from the vcpu
memcache, and the host controls the vcpu memcache via the topup
interface. An under-provisioned donation request would otherwise
turn a recoverable -ENOMEM into a fatal hyp panic.
Bound the worst-case walker allocation alongside the existing
__host_check_page_state_range() / __guest_check_page_state_range()
pre-checks, using the helper introduced for host->guest share. If
the vcpu memcache holds fewer pages than kvm_mmu_cache_min_pages(),
return -ENOMEM before any state mutation.
Fixes: 1e579adca1 ("KVM: arm64: Introduce __pkvm_host_donate_guest()")
Assisted-by: Gemini:gemini-3.1-pro review-prompts
Signed-off-by: Fuad Tabba <tabba@google.com>
Link: https://patch.msgid.link/20260501112149.2824881-7-tabba@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
__pkvm_host_share_guest() ends with kvm_pgtable_stage2_map() to
install the guest stage-2 mapping, after a forward pass that mutates
the host vmemmap (sets PKVM_PAGE_SHARED_OWNED and increments
host_share_guest_count) for every page in the range. The map's
return value is wrapped in WARN_ON() and otherwise discarded,
asserting that the call cannot fail.
WARN_ON() at nVHE EL2 panics, so this assertion is only correct if
the call genuinely cannot fail. kvm_pgtable_stage2_map() can fail
with -ENOMEM when the stage-2 walker exhausts the caller's
memcache, and the host controls the vcpu memcache via the topup
interface, so an under-provisioned share request would otherwise
turn a recoverable -ENOMEM into a fatal hyp panic.
Bound the worst-case walker allocation in the existing pre-check
pass so that kvm_pgtable_stage2_map() cannot fail at the call
site, using kvm_mmu_cache_min_pages() -- the same bound host EL1
uses for its own stage-2 maps. If the vcpu memcache holds fewer
pages, return -ENOMEM before any state mutation.
Fixes: d0bd3e6570 ("KVM: arm64: Introduce __pkvm_host_share_guest()")
Assisted-by: Gemini:gemini-3.1-pro review-prompts
Signed-off-by: Fuad Tabba <tabba@google.com>
Link: https://patch.msgid.link/20260501112149.2824881-6-tabba@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
