Commit Graph

405 Commits

Author SHA1 Message Date
Fuad Tabba
04447b95c6 KVM: arm64: Use the host's HCR_EL2 for non-protected VMs in pKVM
For each vCPU, pKVM's EL2 builds its own HCR_EL2 and takes only TWI, TWE
and VSE from the host's value on each entry. For a non-protected VM it
has fallen behind the host's: on a CPU with MTE the guest can read
GMID_EL1, on one with FEAT_EVT2 but no FGT it can execute a TLBI OS its
ID registers hide, an interrupt injected without a vGIC (VI, VF) never
arrives, and set/way emulation loses the TVM trap it relies on.

For a non-protected VM, also take the bits the host varies with the VM's
configuration or at runtime: VI, VF, TVM, TID2, TID4, TID5 and TTLBOS.
They only pend interrupts for, or add traps to, a VM the host controls.
The traps exit to the host, which handles them as it does without pKVM.
The bits that change what EL2 does on entry and exit (E2H, RW, API/APK)
or depend only on the CPU (TEA, TERR, FWB) stay EL2's. A protected VM
still takes only TWI, TWE and VSE.

EL2 now sets TID2 or TID4 only for a protected VM, and never sets ATA,
as the host rejects KVM_CAP_ARM_MTE in pKVM.

Fixes: b56680de9c ("KVM: arm64: Initialize trap register values in hyp in pKVM")
Signed-off-by: Fuad Tabba <fuad.tabba@linux.dev>
Link: https://patch.msgid.link/20260929090031.3829185-4-fuad.tabba@linux.dev
Signed-off-by: Oliver Upton <oupton@kernel.org>
2026-09-29 09:08:56 -07:00
Fuad Tabba
cfe80c3837 KVM: arm64: Check every private mapping is hyp-owned at pKVM init
fix_host_ownership() transfers only what it walks, so a hyp mapping
outside the linear map is not manipulated by the walk.

Walk the quarter of the VA space holding the private range and the
vmemmap once the transfer is done, and fail init unless every valid
leaf is hyp-owned: in the vmemmap when the page is memory, and in the
host stage-2, where hyp text may instead be mapped without write
access. A leaf that is not memory has no vmemmap entry and is checked
against the host stage-2 alone. Hyp text is matched by physical
address, since the only executable mapping in the range is the
Spectre-v3a vectors, whose VA is a private allocation, and an
executable mapping of anything else must not be host-readable. The
vmemmap can be block-mapped, so the walker checks each page of a leaf.

Suggested-by: Will Deacon <will@kernel.org>
Signed-off-by: Fuad Tabba <fuad.tabba@linux.dev>
Reviewed-by: Vincent Donnefort <vdonnefort@google.com>
Tested-by: Vincent Donnefort <vdonnefort@google.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://patch.msgid.link/20260908110713.1540304-5-fuad.tabba@linux.dev
Signed-off-by: Oliver Upton <oupton@kernel.org>
2026-09-15 15:09:57 -07:00
Fuad Tabba
5a8b505ede KVM: arm64: Match hyp text by physical address in fix_host_ownership()
On a non-hVHE host, fix_host_ownership_walker()'s test for PAGE_HYP_EXEC
never matches: KVM_PGTABLE_PROT_UX is cleared at map time and only PX is
reported on read-back. Hyp text is therefore donated rather than left
read-only in the host stage-2, and the instruction dump in
nvhe_hyp_panic_handler() reads a page the host has no access to.

Match the text by physical address instead, in a helper a later patch
reuses. A test on the permissions would leave any other executable
mapping host-readable too.

Fixes: 80cbfd7174 ("KVM: arm64: Honor UX/PX attributes for EL2 S1 mappings")
Signed-off-by: Fuad Tabba <fuad.tabba@linux.dev>
Reviewed-by: Vincent Donnefort <vdonnefort@google.com>
Tested-by: Vincent Donnefort <vdonnefort@google.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://patch.msgid.link/20260908110713.1540304-3-fuad.tabba@linux.dev
Signed-off-by: Oliver Upton <oupton@kernel.org>
2026-09-15 15:09:57 -07:00
Oliver Upton
5f44f603b0 Merge branch 'kvm-arm64/feat-nv3' into next
* kvm-arm64/feat-nv3: (29 commits)
  : Support for FEAT_NV2p1 and FEAT_NV3, courtesy of Marc Zyngier
  :
  : Couple of accelerations for nested virtualization:
  :
  :  - Elide traps for EL1 alias registers when hardware guarantees that
  :    EL2-only bits are stateful (NV2p1)
  :
  :  - Use TGE-aware hardware to avoid unnecesary ERET/TLBI traps that
  :    remain 'in-context' (i.e. L1 kernel/userspace)
  arm64: Add override for ID_AA64MMFR4_EL1.NV_frac
  KVM: arm64: selftest: Add NVHCR_EL2 to get-reg-list
  KVM: arm64: Expose FEAT_NV3 to guests
  KVM: arm64: Add FEAT_NV3 detection
  KVM: arm64: Engage NV3 TLBI trap elision
  KVM: arm64: Engage NV3 ERET trap elision
  KVM: arm64: Add NVHCR_EL2 context switching
  KVM: arm64: Add routing for NVHCR_EL2 trap
  KVM: arm64: Add NVHCR_EL2 handling to the sysreg array
  KVM: arm64: Add sanitisation for NVHCR_EL2
  KVM: arm64: Make HCR_EL2 a non-VNCR register
  KVM: arm64: Add kvm_has_nv{2,3}() predicates
  KVM: arm64: Add NV3 control bits to HCRX_EL2 sanitisation
  KVM: arm64: Split NV-specific exit fixups from the non-NV handling
  arm64: Add ARM64_HAS_NV3 capability
  arm64: sysreg: Add HCRX_EL2 bits related to FEAT_NV3
  arm64: sysreg: Add NVHCR_EL2 description as a mirror of HCR_EL2
  arm64: Add FEAT_NV2p1 detection
  KVM: arm64: Expose FEAT_NV2p1 to NV guests
  KVM: arm64: Relax CNTHCTL_EL2 handling when FEAT_NV2p1 is present
  ...

Signed-off-by: Oliver Upton <oupton@kernel.org>
2026-08-19 12:27:53 -07:00
Oliver Upton
5279b2f422 Merge branch 'kvm-arm64/pkvm-7.3' into next
* kvm-arm64/pkvm-7.3: (26 commits)
  : pKVM updates for 7.3
  :
  :  - Avoid name collision on trace_clock() when CONFIG_NVHE_EL2_TRACING is
  :    disabled (Mostafa Saleh)
  :
  :  - Clean up state tracking for whether the EL2 shadow VM has been
  :    created (Fuad Tabba)
  :
  :  - Synchronize SCTLR_EL1 when injecting an exception to use current
  :    PAN/SSBS state (Fuad Tabba)
  :
  :  - Avoid unnecessary cache maintenance when I/D-cache are known to be
  :    coherent in pKVM (Mostafa Saleh)
  :
  :  - Lazy vCPU context save/restore for pKVM (Fuad Tabba)
  :
  :  - Various fixes to the stage-2 MMU for pKVM (Fuad Tabba)
  :
  :  - Allow counter offsetting of non-protected guests in protected mode
  :    (Mostafa Saleh)
  :
  :  - Condition the 'broken CNTVOFF' mitigation on a VM actually having a
  :    nonzero offset, fixing boot failures of pVMs on affected hardware
  :    (Mostafa Saleh)
  KVM: arm64: Fix hvhe and broken CNTVOFF_EL2
  KVM: arm64: Fix timer offsets for non-protected VMs
  KVM: arm64: Make timer_get_offset() work in all contexts
  KVM: arm64: selftests: Add stage-2 block transition test
  KVM: arm64: Don't advertise eager page splitting under pKVM
  KVM: arm64: Don't WARN on pKVM stage-2 map failures
  KVM: arm64: Skip pKVM stage-2 flush when FWB is enabled
  KVM: arm64: Top up stage-2 memcache for dirty logging faults
  KVM: arm64: Top up the memcache for pKVM permission faults
  KVM: arm64: Skip cache maintenance for non-cacheable pKVM mappings
  KVM: arm64: Implement lazy vCPU state sync for non-protected guests
  KVM: arm64: Add primitives to flush/sync the VGIC state at EL2
  KVM: arm64: Minimise EL2's exposure of host VGIC state during world switch
  KVM: arm64: Add host and hypervisor vCPU lookup primitives
  KVM: arm64: Move PSCI helper functions to a shared header
  KVM: arm64: Factor out reusable vCPU reset helpers
  KVM: arm64: Make vcpu_{read,write}_sys_reg available to HYP code
  KVM: arm64: Extract MPIDR computation into a shared header
  KVM: arm64: selftests: Add a userspace watchpoint test
  KVM: arm64: Flush external_mdscr_el1 to the pKVM hyp vCPU
  ...

Signed-off-by: Oliver Upton <oupton@kernel.org>
2026-08-19 12:27:35 -07:00
Marc Zyngier
2858600ecd KVM: arm64: Make timer_get_offset() work in all contexts
We currently have two implementations of get_timer offset(), one
in arm_arch_timer.h, and another one in switch.h.

These two only differ by a pair of kern_hyp_va(), which seems a
pretty weak reason to open-code it.

Turn this function into a macro to avoid the include dependency hell
on kern_hyp_va(), and make it work correctly in all contexts.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Mostafa Saleh <smostafa@google.com>
Link: https://patch.msgid.link/20260808085824.732659-2-smostafa@google.com
Signed-off-by: Oliver Upton <oupton@kernel.org>
2026-08-08 11:38:49 -07:00
Marc Zyngier
62ed180231 KVM: arm64: Add NVHCR_EL2 context switching
Since NVHCR_EL2 represents the HCR_EL2 state of the EL1 guest, it
must be dealt with in some particular way:

- for a guest in hyp context (an L1 by definition), NVHCR_EL2 directly
  reflects HCR_EL2 as read and written by the guest itself. It must
  therefore be eagerly synced back with the emulation code which only
  knows about HCR_EL2. This is unconditional if NV3 is available on
  the host.

- For an L2 guest, NVHCR_EL2 is controlled by the L1 guest, and we
  just context switch it like any other EL1 register. Yes, EL1, as
  that's where this thing runs from the PoV of L1. This is conditioned
  on the guest using NV3.

Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Reviewed-by: Yuan Yao <yaoyuan@linux.alibaba.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://patch.msgid.link/20260730071022.296811-24-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2026-07-31 00:17:04 -07:00
Marc Zyngier
649ba04326 KVM: arm64: Relax CPTR_EL2 handling when FEAT_NV2p1 is present
With FEAT_NV2P1, it is no longer necessary to trap CPTR_EL2 accesses
via CPACR_EL1, as CPACR_EL1.TCPAC is guaranteed to be stateful.

Prevent such trapping and context switch CPACTR_EL1 in NV contexts
when NV2P1 is present.

Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Reviewed-by: Yuan Yao <yaoyuan@linux.alibaba.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://patch.msgid.link/20260730071022.296811-10-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2026-07-31 00:17:03 -07:00
Marc Zyngier
4422d8b750 KVM: arm64: Merge guest's HCRX_EL2 using NV_HCRX_GUEST_EXCLUDE
The way we merge the guest-provided HCRX_EL2 value with the host's
is bonkers. We try to make it look like the FGT registers by using
positive and negative polarities for traps, but most of these bits
are not strictly about trapping, as they actively change the way
some architectural state is managed.

It would be far better to deal with these bits like we do for
HCR_EL2, by enumerating the list of bits we don't allow the guest
to override. This is simplified by the fact that HCRX_EL2 only
affects EL1, and not EL2.

Re-jig the HCRX_EL2 handling with a macro that list the bits excluded
from the merge (TMEA, PTTWI, EnIDCP128).

Reviewed-by: Yuan Yao <yaoyuan@linux.alibaba.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Link: https://patch.msgid.link/20260730071022.296811-4-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2026-07-31 00:17:02 -07:00
Paolo Bonzini
5b0d0464f6 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!
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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!
2026-07-15 12:12:37 +02:00
Mostafa Saleh
007e0f0fd9 KVM: arm64: Avoid naming collision in tracing
When the hypervisor tracing (CONFIG_NVHE_EL2_TRACING) is disabled, it
defines a static inline stub for trace_clock().

However, trace_clock() is already declared as an extern function in
linux/trace_clock.h which is pulled in EL2 compilation.

If the file <nvhe/clock.h> is included when CONFIG_NVHE_EL2_TRACING
is disabled (by including it manually in setup.c) it will cause:
In file included from arch/arm64/kvm/hyp/nvhe/setup.c:22:

./arch/arm64/kvm/hyp/include/nvhe/clock.h:14:19: error: static declaration of ‘trace_clock’ follows non-static declaration

   14 | static inline u64 trace_clock(void) { return 0; }

      |                   ^~~~~~~~~~~

on GCC and a linker error on LLVM (it seems to change the linkage to
global)

Although that is not a problem at the moment, as no other files
include <nvhe/clock.h>. That does not seem to be the intent of
this code and that will cause issues with more users as the SMMUv3
driver.

Signed-off-by: Mostafa Saleh <smostafa@google.com>
Reviewed-by: Fuad Tabba <fuad.tabba@linux.dev>
Tested-by: Fuad Tabba <fuad.tabba@linux.dev>
Reviewed-by: Vincent Donnefort <vdonnefort@google.com>
Link: https://patch.msgid.link/20260713141320.4065600-1-smostafa@google.com
Signed-off-by: Oliver Upton <oupton@kernel.org>
2026-07-13 15:30:19 -07:00
Linus Torvalds
c98d767b34 Arm:
"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
  ...
2026-06-19 08:56:49 -07:00
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
Linus Torvalds
80476f22b8 arm64 updates for 7.2
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
  ...
2026-06-16 05:18:04 +05:30
Paolo Bonzini
751d041a13 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.
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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.
2026-06-12 10:51:42 +02:00
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
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
Joey Gouly
cbaffe843a KVM: arm64: Restore POR_EL0 access to host EL0
CPTR_EL2.E0POE was being cleared in __deactivate_cptr_traps_vhe(), which meant
that any accesses to POR_EL0 from host EL0 would trap and be reported to
userspace as an Illegal instruction. This would happen after running any VM,
regardless if it used POE or not.

Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Link: https://sashiko.dev/#/patchset/20260602155430.2088142-1-maz@kernel.org?part=1
Link: https://patch.msgid.link/20260604105434.2297268-1-joey.gouly@arm.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger,kernel.org
2026-06-05 11:48:24 +01:00
Marc Zyngier
978cd6b2ad KVM: arm64: Key CPTR_EL2.E0POE propagation on FEAT_S1POE
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>
2026-06-03 21:01:48 +01:00
Mark Rutland
2768101b39 arm64: fpsimd: Move SVE save/restore inline
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>
2026-06-03 16:50:49 +01:00
Mark Rutland
e1b163e405 arm64: fpsimd: Use opaque type for SVE state
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>
2026-06-03 16:50:49 +01:00
Mark Rutland
890712d450 arm64: fpsimd: Move fpsimd save/restore inline
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>
2026-06-03 16:50:49 +01:00
Mark Rutland
1277531fca arm64: fpsimd: Split FPSR/FPCR from SVE save/restore
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>
2026-06-03 16:50:48 +01:00
Mark Rutland
afd7af2b56 KVM: arm64: pkvm: Remove struct cpu_sve_state
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>
2026-06-03 16:50:48 +01:00
Mark Rutland
da20bb4bc5 KVM: arm64: pkvm: Save host FPMR in host cpu context
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>
2026-06-03 16:50:47 +01:00
Mark Brown
8372633074 KVM: arm64: Correctly cap ZCR_EL2 provided by a guest hypervisor
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>
2026-05-29 10:04:00 +01:00
Zenghui Yu (Huawei)
e72b425f61 KVM: arm64: Remove @arch from __load_stage2()
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>
2026-05-28 18:52:55 +01:00
Fuad Tabba
1bdcdc84f9 KVM: arm64: Fix __deactivate_fgt macro parameter typo
__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>
2026-05-27 14:20:56 +01:00
Vincent Donnefort
20d2753295 KVM: arm64: Fix __pkvm_init_vm error path
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>
2026-05-26 16:12:29 +01:00
Fuad Tabba
d4d215e5b8 KVM: arm64: Fix __deactivate_fgt macro parameter typo
__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>
2026-05-07 14:12:41 +01:00
Linus Torvalds
01f492e181 Arm:
- Add support for tracing in the standalone EL2 hypervisor code, which
   should help both debugging and performance analysis.  This uses the
   new infrastructure for 'remote' trace buffers that can be exposed
   by non-kernel entities such as firmware, and which came through the
   tracing tree.
 
 - Add support for GICv5 Per Processor Interrupts (PPIs), as the starting
   point for supporting the new GIC architecture in KVM.
 
 - Finally add support for pKVM protected guests, where pages are unmapped
   from the host as they are faulted into the guest and can be shared back
   from the guest using pKVM hypercalls.  Protected guests are created
   using a new machine type identifier.  As the elusive guestmem has not
   yet delivered on its promises, anonymous memory is also supported.
 
   This is only a first step towards full isolation from the host; for
   example, the CPU register state and DMA accesses are not yet isolated.
   Because this does not really yet bring fully what it promises, it is
   hidden behind CONFIG_ARM_PKVM_GUEST + 'kvm-arm.mode=protected', and
   also triggers TAINT_USER when a VM is created.  Caveat emptor.
 
 - Rework the dreaded user_mem_abort() function to make it more
   maintainable, reducing the amount of state being exposed to the
   various helpers and rendering a substantial amount of state immutable.
 
 - Expand the Stage-2 page table dumper to support NV shadow page tables
   on a per-VM basis.
 
 - Tidy up the pKVM PSCI proxy code to be slightly less hard to follow.
 
 - Fix both SPE and TRBE in non-VHE configurations so that they do not
   generate spurious, out of context table walks that ultimately lead
   to very bad HW lockups.
 
 - A small set of patches fixing the Stage-2 MMU freeing in error cases.
 
 - Tighten-up accepted SMC immediate value to be only #0 for host
   SMCCC calls.
 
 - The usual cleanups and other selftest churn.
 
 LoongArch:
 
 - Use CSR_CRMD_PLV for kvm_arch_vcpu_in_kernel().
 
 - Add DMSINTC irqchip in kernel support.
 
 RISC-V:
 
 - Fix steal time shared memory alignment checks
 
 - Fix vector context allocation leak
 
 - Fix array out-of-bounds in pmu_ctr_read() and pmu_fw_ctr_read_hi()
 
 - Fix double-free of sdata in kvm_pmu_clear_snapshot_area()
 
 - Fix integer overflow in kvm_pmu_validate_counter_mask()
 
 - Fix shift-out-of-bounds in make_xfence_request()
 
 - Fix lost write protection on huge pages during dirty logging
 
 - Split huge pages during fault handling for dirty logging
 
 - Skip CSR restore if VCPU is reloaded on the same core
 
 - Implement kvm_arch_has_default_irqchip() for KVM selftests
 
 - Factored-out ISA checks into separate sources
 
 - Added hideleg to struct kvm_vcpu_config
 
 - Factored-out VCPU config into separate sources
 
 - Support configuration of per-VM HGATP mode from KVM user space
 
 s390:
 
 - Support for ESA (31-bit) guests inside nested hypervisors.
 
 - Remove restriction on memslot alignment, which is not needed anymore with
   the new gmap code.
 
 - Fix LPSW/E to update the bear (which of course is the breaking event
   address register).
 
 x86:
 
 - Shut up various UBSAN warnings on reading module parameter before they
   were initialized.
 
 - Don't zero-allocate page tables that are used for splitting hugepages in
   the TDP MMU, as KVM is guaranteed to set all SPTEs in the page table and
   thus write all bytes.
 
 - As an optimization, bail early when trying to unsync 4KiB mappings if the
   target gfn can just be mapped with a 2MiB hugepage.
 
 x86 generic:
 
 - Copy single-chunk MMIO write values into struct kvm_vcpu (more precisely
   struct kvm_mmio_fragment) to fix use-after-free stack bugs where KVM
   would dereference stack pointer after an exit to userspace.
 
 - Clean up and comment the emulated MMIO code to try to make it easier to
   maintain (not necessarily "easy", but "easier").
 
 - Move VMXON+VMXOFF and EFER.SVME toggling out of KVM (not *all* of VMX
   and SVM enabling) as it is needed for trusted I/O.
 
 - Advertise support for AVX512 Bit Matrix Multiply (BMM) instructions
 
 - Immediately fail the build if a required #define is missing in one of
   KVM's headers that is included multiple times.
 
 - Reject SET_GUEST_DEBUG with -EBUSY if there's an already injected
   exception, mostly to prevent syzkaller from abusing the uAPI to
   trigger WARNs, but also because it can help prevent userspace from
   unintentionally crashing the VM.
 
 - Exempt SMM from CPUID faulting on Intel, as per the spec.
 
 - Misc hardening and cleanup changes.
 
 x86 (AMD):
 
 - Fix and optimize IRQ window inhibit handling for AVIC; make it per-vCPU
   so that KVM doesn't prematurely re-enable AVIC if multiple
   vCPUs have to-be-injected IRQs.
 
 - Clean up and optimize the OSVW handling, avoiding a bug in which KVM would
   overwrite state when enabling virtualization on multiple CPUs in parallel.
   This should not be a problem because OSVW should usually be the same for
   all CPUs.
 
 - Drop a WARN in KVM_MEMORY_ENCRYPT_REG_REGION where KVM complains about a
   "too large" size based purely on user input.
 
 - Clean up and harden the pinning code for KVM_MEMORY_ENCRYPT_REG_REGION.
 
 - Disallow synchronizing a VMSA of an already-launched/encrypted vCPU, as
   doing so for an SNP guest will crash the host due to an RMP violation
   page fault.
 
 - Overhaul KVM's APIs for detecting SEV+ guests so that VM-scoped queries
   are required to hold kvm->lock, and enforce it by lockdep.  Fix various
   bugs where sev_guest() was not ensured to be stable for the whole
   duration of a function or ioctl.
 
 - Convert a pile of kvm->lock SEV code to guard().
 
 - Play nicer with userspace that does not enable KVM_CAP_EXCEPTION_PAYLOAD,
   for which KVM needs to set CR2 and DR6 as a response to ioctls such as
   KVM_GET_VCPU_EVENTS (even if the payload would end up in EXITINFO2
   rather than CR2, for example).  Only set CR2 and DR6 when consumption of
   the payload is imminent, but on the other hand force delivery of the
   payload in all paths where userspace retrieves CR2 or DR6.
 
 - Use vcpu->arch.cr2 when updating vmcb12's CR2 on nested #VMEXIT instead
   of vmcb02->save.cr2.  The value is out of sync after a save/restore
   or after a #PF is injected into L2.
 
 - Fix a class of nSVM bugs where some fields written by the CPU are not
   synchronized from vmcb02 to cached vmcb12 after VMRUN, and so are not
   up-to-date when saved by KVM_GET_NESTED_STATE.
 
 - Fix a class of bugs where the ordering between KVM_SET_NESTED_STATE and
   KVM_SET_{S}REGS could cause vmcb02 to be incorrectly initialized after
   save+restore.
 
 - Add a variety of missing nSVM consistency checks.
 
 - Fix several bugs where KVM failed to correctly update VMCB fields on
   nested #VMEXIT.
 
 - Fix several bugs where KVM failed to correctly synthesize #UD or #GP for
   SVM-related instructions.
 
 - Add support for save+restore of virtualized LBRs (on SVM).
 
 - Refactor various helpers and macros to improve clarity and (hopefully)
   make the code easier to maintain.
 
 - Aggressively sanitize fields when copying from vmcb12, to guard against
   unintentionally allowing L1 to utilize yet-to-be-defined features.
 
 - Fix several bugs where KVM botched rAX legality checks when emulating SVM
   instructions.  There are remaining issues in that KVM doesn't handle size
   prefix overrides for 64-bit guests.
 
 - Fail emulation of VMRUN/VMLOAD/VMSAVE if mapping vmcb12 fails instead of
   somewhat arbitrarily synthesizing #GP (i.e. don't double down on AMD's
   architectural but sketchy behavior of generating #GP for "unsupported"
   addresses).
 
 - Cache all used vmcb12 fields to further harden against TOCTOU bugs.
 
 x86 (Intel):
 
 - Drop obsolete branch hint prefixes from the VMX instruction macros.
 
 - Use ASM_INPUT_RM() in __vmcs_writel() to coerce clang into using a
   register input when appropriate.
 
 - Code cleanups.
 
 guest_memfd:
 
 - Don't mark guest_memfd folios as accessed, as guest_memfd doesn't support
   reclaim, the memory is unevictable, and there is no storage to write
   back to.
 
 LoongArch selftests:
 
 - Add KVM PMU test cases
 
 s390 selftests:
 
 - Enable more memory selftests.
 
 x86 selftests:
 
 - Add support for Hygon CPUs in KVM selftests.
 
 - Fix a bug in the MSR test where it would get false failures on AMD/Hygon
   CPUs with exactly one of RDPID or RDTSCP.
 
 - Add an MADV_COLLAPSE testcase for guest_memfd as a regression test for a
   bug where the kernel would attempt to collapse guest_memfd folios against
   KVM's will.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm updates from Paolo Bonzini:
 "Arm:

   - Add support for tracing in the standalone EL2 hypervisor code,
     which should help both debugging and performance analysis. This
     uses the new infrastructure for 'remote' trace buffers that can be
     exposed by non-kernel entities such as firmware, and which came
     through the tracing tree

   - Add support for GICv5 Per Processor Interrupts (PPIs), as the
     starting point for supporting the new GIC architecture in KVM

   - Finally add support for pKVM protected guests, where pages are
     unmapped from the host as they are faulted into the guest and can
     be shared back from the guest using pKVM hypercalls. Protected
     guests are created using a new machine type identifier. As the
     elusive guestmem has not yet delivered on its promises, anonymous
     memory is also supported

     This is only a first step towards full isolation from the host; for
     example, the CPU register state and DMA accesses are not yet
     isolated. Because this does not really yet bring fully what it
     promises, it is hidden behind CONFIG_ARM_PKVM_GUEST +
     'kvm-arm.mode=protected', and also triggers TAINT_USER when a VM is
     created. Caveat emptor

   - Rework the dreaded user_mem_abort() function to make it more
     maintainable, reducing the amount of state being exposed to the
     various helpers and rendering a substantial amount of state
     immutable

   - Expand the Stage-2 page table dumper to support NV shadow page
     tables on a per-VM basis

   - Tidy up the pKVM PSCI proxy code to be slightly less hard to
     follow

   - Fix both SPE and TRBE in non-VHE configurations so that they do not
     generate spurious, out of context table walks that ultimately lead
     to very bad HW lockups

   - A small set of patches fixing the Stage-2 MMU freeing in error
     cases

   - Tighten-up accepted SMC immediate value to be only #0 for host
     SMCCC calls

   - The usual cleanups and other selftest churn

  LoongArch:

   - Use CSR_CRMD_PLV for kvm_arch_vcpu_in_kernel()

   - Add DMSINTC irqchip in kernel support

  RISC-V:

   - Fix steal time shared memory alignment checks

   - Fix vector context allocation leak

   - Fix array out-of-bounds in pmu_ctr_read() and pmu_fw_ctr_read_hi()

   - Fix double-free of sdata in kvm_pmu_clear_snapshot_area()

   - Fix integer overflow in kvm_pmu_validate_counter_mask()

   - Fix shift-out-of-bounds in make_xfence_request()

   - Fix lost write protection on huge pages during dirty logging

   - Split huge pages during fault handling for dirty logging

   - Skip CSR restore if VCPU is reloaded on the same core

   - Implement kvm_arch_has_default_irqchip() for KVM selftests

   - Factored-out ISA checks into separate sources

   - Added hideleg to struct kvm_vcpu_config

   - Factored-out VCPU config into separate sources

   - Support configuration of per-VM HGATP mode from KVM user space

  s390:

   - Support for ESA (31-bit) guests inside nested hypervisors

   - Remove restriction on memslot alignment, which is not needed
     anymore with the new gmap code

   - Fix LPSW/E to update the bear (which of course is the breaking
     event address register)

  x86:

   - Shut up various UBSAN warnings on reading module parameter before
     they were initialized

   - Don't zero-allocate page tables that are used for splitting
     hugepages in the TDP MMU, as KVM is guaranteed to set all SPTEs in
     the page table and thus write all bytes

   - As an optimization, bail early when trying to unsync 4KiB mappings
     if the target gfn can just be mapped with a 2MiB hugepage

  x86 generic:

   - Copy single-chunk MMIO write values into struct kvm_vcpu (more
     precisely struct kvm_mmio_fragment) to fix use-after-free stack
     bugs where KVM would dereference stack pointer after an exit to
     userspace

   - Clean up and comment the emulated MMIO code to try to make it
     easier to maintain (not necessarily "easy", but "easier")

   - Move VMXON+VMXOFF and EFER.SVME toggling out of KVM (not *all* of
     VMX and SVM enabling) as it is needed for trusted I/O

   - Advertise support for AVX512 Bit Matrix Multiply (BMM) instructions

   - Immediately fail the build if a required #define is missing in one
     of KVM's headers that is included multiple times

   - Reject SET_GUEST_DEBUG with -EBUSY if there's an already injected
     exception, mostly to prevent syzkaller from abusing the uAPI to
     trigger WARNs, but also because it can help prevent userspace from
     unintentionally crashing the VM

   - Exempt SMM from CPUID faulting on Intel, as per the spec

   - Misc hardening and cleanup changes

  x86 (AMD):

   - Fix and optimize IRQ window inhibit handling for AVIC; make it
     per-vCPU so that KVM doesn't prematurely re-enable AVIC if multiple
     vCPUs have to-be-injected IRQs

   - Clean up and optimize the OSVW handling, avoiding a bug in which
     KVM would overwrite state when enabling virtualization on multiple
     CPUs in parallel. This should not be a problem because OSVW should
     usually be the same for all CPUs

   - Drop a WARN in KVM_MEMORY_ENCRYPT_REG_REGION where KVM complains
     about a "too large" size based purely on user input

   - Clean up and harden the pinning code for KVM_MEMORY_ENCRYPT_REG_REGION

   - Disallow synchronizing a VMSA of an already-launched/encrypted
     vCPU, as doing so for an SNP guest will crash the host due to an
     RMP violation page fault

   - Overhaul KVM's APIs for detecting SEV+ guests so that VM-scoped
     queries are required to hold kvm->lock, and enforce it by lockdep.
     Fix various bugs where sev_guest() was not ensured to be stable for
     the whole duration of a function or ioctl

   - Convert a pile of kvm->lock SEV code to guard()

   - Play nicer with userspace that does not enable
     KVM_CAP_EXCEPTION_PAYLOAD, for which KVM needs to set CR2 and DR6
     as a response to ioctls such as KVM_GET_VCPU_EVENTS (even if the
     payload would end up in EXITINFO2 rather than CR2, for example).
     Only set CR2 and DR6 when consumption of the payload is imminent,
     but on the other hand force delivery of the payload in all paths
     where userspace retrieves CR2 or DR6

   - Use vcpu->arch.cr2 when updating vmcb12's CR2 on nested #VMEXIT
     instead of vmcb02->save.cr2. The value is out of sync after a
     save/restore or after a #PF is injected into L2

   - Fix a class of nSVM bugs where some fields written by the CPU are
     not synchronized from vmcb02 to cached vmcb12 after VMRUN, and so
     are not up-to-date when saved by KVM_GET_NESTED_STATE

   - Fix a class of bugs where the ordering between KVM_SET_NESTED_STATE
     and KVM_SET_{S}REGS could cause vmcb02 to be incorrectly
     initialized after save+restore

   - Add a variety of missing nSVM consistency checks

   - Fix several bugs where KVM failed to correctly update VMCB fields
     on nested #VMEXIT

   - Fix several bugs where KVM failed to correctly synthesize #UD or
     #GP for SVM-related instructions

   - Add support for save+restore of virtualized LBRs (on SVM)

   - Refactor various helpers and macros to improve clarity and
     (hopefully) make the code easier to maintain

   - Aggressively sanitize fields when copying from vmcb12, to guard
     against unintentionally allowing L1 to utilize yet-to-be-defined
     features

   - Fix several bugs where KVM botched rAX legality checks when
     emulating SVM instructions. There are remaining issues in that KVM
     doesn't handle size prefix overrides for 64-bit guests

   - Fail emulation of VMRUN/VMLOAD/VMSAVE if mapping vmcb12 fails
     instead of somewhat arbitrarily synthesizing #GP (i.e. don't double
     down on AMD's architectural but sketchy behavior of generating #GP
     for "unsupported" addresses)

   - Cache all used vmcb12 fields to further harden against TOCTOU bugs

  x86 (Intel):

   - Drop obsolete branch hint prefixes from the VMX instruction macros

   - Use ASM_INPUT_RM() in __vmcs_writel() to coerce clang into using a
     register input when appropriate

   - Code cleanups

  guest_memfd:

   - Don't mark guest_memfd folios as accessed, as guest_memfd doesn't
     support reclaim, the memory is unevictable, and there is no storage
     to write back to

  LoongArch selftests:

   - Add KVM PMU test cases

  s390 selftests:

   - Enable more memory selftests

  x86 selftests:

   - Add support for Hygon CPUs in KVM selftests

   - Fix a bug in the MSR test where it would get false failures on
     AMD/Hygon CPUs with exactly one of RDPID or RDTSCP

   - Add an MADV_COLLAPSE testcase for guest_memfd as a regression test
     for a bug where the kernel would attempt to collapse guest_memfd
     folios against KVM's will"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (373 commits)
  KVM: x86: use inlines instead of macros for is_sev_*guest
  x86/virt: Treat SVM as unsupported when running as an SEV+ guest
  KVM: SEV: Goto an existing error label if charging misc_cg for an ASID fails
  KVM: SVM: Move lock-protected allocation of SEV ASID into a separate helper
  KVM: SEV: use mutex guard in snp_handle_guest_req()
  KVM: SEV: use mutex guard in sev_mem_enc_unregister_region()
  KVM: SEV: use mutex guard in sev_mem_enc_ioctl()
  KVM: SEV: use mutex guard in snp_launch_update()
  KVM: SEV: Assert that kvm->lock is held when querying SEV+ support
  KVM: SEV: Document that checking for SEV+ guests when reclaiming memory is "safe"
  KVM: SEV: Hide "struct kvm_sev_info" behind CONFIG_KVM_AMD_SEV=y
  KVM: SEV: WARN on unhandled VM type when initializing VM
  KVM: LoongArch: selftests: Add PMU overflow interrupt test
  KVM: LoongArch: selftests: Add basic PMU event counting test
  KVM: LoongArch: selftests: Add cpucfg read/write helpers
  LoongArch: KVM: Add DMSINTC inject msi to vCPU
  LoongArch: KVM: Add DMSINTC device support
  LoongArch: KVM: Make vcpu_is_preempted() as a macro rather than function
  LoongArch: KVM: Move host CSR_GSTAT save and restore in context switch
  LoongArch: KVM: Move host CSR_EENTRY save and restore in context switch
  ...
2026-04-17 07:18:03 -07:00
Marc Zyngier
83a3980750 Merge branch kvm-arm64/pkvm-protected-guest into kvmarm-master/next
* kvm-arm64/pkvm-protected-guest: (41 commits)
  : .
  : pKVM support for protected guests, implementing the very long
  : awaited support for anonymous memory, as the elusive guestmem
  : has failed to deliver on its promises despite a multi-year
  : effort. Patches courtesy of Will Deacon. From the initial cover
  : letter:
  :
  : "[...] this patch series implements support for protected guest
  : memory with pKVM, where pages are unmapped from the host as they are
  : faulted into the guest and can be shared back from the guest using pKVM
  : hypercalls. Protected guests are created using a new machine type
  : identifier and can be booted to a shell using the kvmtool patches
  : available at [2], which finally means that we are able to test the pVM
  : logic in pKVM. Since this is an incremental step towards full isolation
  : from the host (for example, the CPU register state and DMA accesses are
  : not yet isolated), creating a pVM requires a developer Kconfig option to
  : be enabled in addition to booting with 'kvm-arm.mode=protected' and
  : results in a kernel taint."
  : .
  KVM: arm64: Don't hold 'vm_table_lock' across guest page reclaim
  KVM: arm64: Allow get_pkvm_hyp_vm() to take a reference to a dying VM
  KVM: arm64: Prevent teardown finalisation of referenced 'hyp_vm'
  drivers/virt: pkvm: Add Kconfig dependency on DMA_RESTRICTED_POOL
  KVM: arm64: Rename PKVM_PAGE_STATE_MASK
  KVM: arm64: Extend pKVM page ownership selftests to cover guest hvcs
  KVM: arm64: Extend pKVM page ownership selftests to cover forced reclaim
  KVM: arm64: Register 'selftest_vm' in the VM table
  KVM: arm64: Extend pKVM page ownership selftests to cover guest donation
  KVM: arm64: Add some initial documentation for pKVM
  KVM: arm64: Allow userspace to create protected VMs when pKVM is enabled
  KVM: arm64: Implement the MEM_UNSHARE hypercall for protected VMs
  KVM: arm64: Implement the MEM_SHARE hypercall for protected VMs
  KVM: arm64: Add hvc handler at EL2 for hypercalls from protected VMs
  KVM: arm64: Return -EFAULT from VCPU_RUN on access to a poisoned pte
  KVM: arm64: Reclaim faulting page from pKVM in spurious fault handler
  KVM: arm64: Introduce hypercall to force reclaim of a protected page
  KVM: arm64: Annotate guest donations with handle and gfn in host stage-2
  KVM: arm64: Change 'pkvm_handle_t' to u16
  KVM: arm64: Introduce host_stage2_set_owner_metadata_locked()
  ...

Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-04-08 12:25:39 +01:00
Marc Zyngier
f8078d51ee Merge branch kvm-arm64/vgic-v5-ppi into kvmarm-master/next
* kvm-arm64/vgic-v5-ppi: (40 commits)
  : .
  : Add initial GICv5 support for KVM guests, only adding PPI support
  : for the time being. Patches courtesy of Sascha Bischoff.
  :
  : From the cover letter:
  :
  : "This is v7 of the patch series to add the virtual GICv5 [1] device
  : (vgic_v5). Only PPIs are supported by this initial series, and the
  : vgic_v5 implementation is restricted to the CPU interface,
  : only. Further patch series are to follow in due course, and will add
  : support for SPIs, LPIs, the GICv5 IRS, and the GICv5 ITS."
  : .
  KVM: arm64: selftests: Add no-vgic-v5 selftest
  KVM: arm64: selftests: Introduce a minimal GICv5 PPI selftest
  KVM: arm64: gic-v5: Communicate userspace-driveable PPIs via a UAPI
  Documentation: KVM: Introduce documentation for VGICv5
  KVM: arm64: gic-v5: Probe for GICv5 device
  KVM: arm64: gic-v5: Set ICH_VCTLR_EL2.En on boot
  KVM: arm64: gic-v5: Introduce kvm_arm_vgic_v5_ops and register them
  KVM: arm64: gic-v5: Hide FEAT_GCIE from NV GICv5 guests
  KVM: arm64: gic: Hide GICv5 for protected guests
  KVM: arm64: gic-v5: Mandate architected PPI for PMU emulation on GICv5
  KVM: arm64: gic-v5: Enlighten arch timer for GICv5
  irqchip/gic-v5: Introduce minimal irq_set_type() for PPIs
  KVM: arm64: gic-v5: Initialise ID and priority bits when resetting vcpu
  KVM: arm64: gic-v5: Create and initialise vgic_v5
  KVM: arm64: gic-v5: Support GICv5 interrupts with KVM_IRQ_LINE
  KVM: arm64: gic-v5: Implement direct injection of PPIs
  KVM: arm64: Introduce set_direct_injection irq_op
  KVM: arm64: gic-v5: Trap and mask guest ICC_PPI_ENABLERx_EL1 writes
  KVM: arm64: gic-v5: Check for pending PPIs
  KVM: arm64: gic-v5: Clear TWI if single task running
  ...

Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-04-08 12:22:35 +01:00
Will Deacon
5bae7bc636 KVM: arm64: Rename PKVM_PAGE_STATE_MASK
Rename PKVM_PAGE_STATE_MASK to PKVM_PAGE_STATE_VMEMMAP_MASK to make it
clear that the mask applies to the page state recorded in the entries
of the 'hyp_vmemmap', rather than page states stored elsewhere (e.g. in
the ptes).

Suggested-by: Alexandru Elisei <alexandru.elisei@arm.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-38-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-03-30 16:58:09 +01:00
Will Deacon
8972a99160 KVM: arm64: Register 'selftest_vm' in the VM table
In preparation for extending the pKVM page ownership selftests to cover
forceful reclaim of donated pages, rework the creation of the
'selftest_vm' so that it is registered in the VM table while the tests
are running.

Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-35-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-03-30 16:58:09 +01:00
Will Deacon
246c976c37 KVM: arm64: Implement the MEM_UNSHARE hypercall for protected VMs
Implement the ARM_SMCCC_KVM_FUNC_MEM_UNSHARE hypercall to allow
protected VMs to unshare memory that was previously shared with the host
using the ARM_SMCCC_KVM_FUNC_MEM_SHARE hypercall.

Reviewed-by: Vincent Donnefort <vdonnefort@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-31-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-03-30 16:58:09 +01:00
Will Deacon
03313efed5 KVM: arm64: Implement the MEM_SHARE hypercall for protected VMs
Implement the ARM_SMCCC_KVM_FUNC_MEM_SHARE hypercall to allow protected
VMs to share memory (e.g. the swiotlb bounce buffers) back to the host.

Reviewed-by: Vincent Donnefort <vdonnefort@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-30-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-03-30 16:58:09 +01:00
Will Deacon
94c5250515 KVM: arm64: Add hvc handler at EL2 for hypercalls from protected VMs
Add a hypercall handler at EL2 for hypercalls originating from protected
VMs. For now, this implements only the FEATURES and MEMINFO calls, but
subsequent patches will implement the SHARE and UNSHARE functions
necessary for virtio.

Unhandled hypercalls (including PSCI) are passed back to the host.

Reviewed-by: Vincent Donnefort <vdonnefort@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-29-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-03-30 16:58:09 +01:00
Will Deacon
5991916392 KVM: arm64: Return -EFAULT from VCPU_RUN on access to a poisoned pte
If a protected vCPU faults on an IPA which appears to be mapped, query
the hypervisor to determine whether or not the faulting pte has been
poisoned by a forceful reclaim. If the pte has been poisoned, return
-EFAULT back to userspace rather than retrying the instruction forever.

Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-28-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-03-30 16:58:09 +01:00
Will Deacon
56080f53a6 KVM: arm64: Introduce hypercall to force reclaim of a protected page
Introduce a new hypercall, __pkvm_force_reclaim_guest_page(), to allow
the host to forcefully reclaim a physical page that was previous donated
to a protected guest. This results in the page being zeroed and the
previous guest mapping being poisoned so that new pages cannot be
subsequently donated at the same IPA.

Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-26-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-03-30 16:58:09 +01:00
Will Deacon
be9ed3529e KVM: arm64: Support translation faults in inject_host_exception()
Extend inject_host_exception() to support the injection of translation
faults on both the data and instruction side to 32-bit and 64-bit EL0
as well as 64-bit EL1. This will be used in a subsequent patch when
resolving an unhandled host stage-2 abort.

Cc: Fuad Tabba <tabba@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-19-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-03-30 16:58:08 +01:00
Will Deacon
0bf5f4d400 KVM: arm64: Introduce __pkvm_reclaim_dying_guest_page()
To enable reclaim of pages from a protected VM during teardown,
introduce a new hypercall to reclaim a single page from a protected
guest that is in the dying state.

Since the EL2 code is non-preemptible, the new hypercall deliberately
acts on a single page at a time so as to allow EL1 to reschedule
frequently during the teardown operation.

Reviewed-by: Vincent Donnefort <vdonnefort@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Co-developed-by: Quentin Perret <qperret@google.com>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-16-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-03-30 16:58:08 +01:00
Will Deacon
1e579adca1 KVM: arm64: Introduce __pkvm_host_donate_guest()
In preparation for supporting protected VMs, whose memory pages are
isolated from the host, introduce a new pKVM hypercall to allow the
donation of pages to a guest.

Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-13-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-03-30 16:58:08 +01:00
Will Deacon
6c58f914eb KVM: arm64: Split teardown hypercall into two phases
In preparation for reclaiming protected guest VM pages from the host
during teardown, split the current 'pkvm_teardown_vm' hypercall into
separate 'start' and 'finalise' calls.

The 'pkvm_start_teardown_vm' hypercall puts the VM into a new 'is_dying'
state, which is a point of no return past which no vCPU of the pVM is
allowed to run any more.  Once in this new state,
'pkvm_finalize_teardown_vm' can be used to reclaim meta-data and
page-table pages from the VM. A subsequent patch will add support for
reclaiming the individual guest memory pages.

Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Co-developed-by: Quentin Perret <qperret@google.com>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-12-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-03-30 16:58:07 +01:00
Will Deacon
660b208e8b KVM: arm64: Remove unused PKVM_ID_FFA definition
Commit 7cbf7c3771 ("KVM: arm64: Drop pkvm_mem_transition for host/hyp
sharing") removed the last users of PKVM_ID_FFA, so drop the definition
altogether.

Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-2-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-03-30 16:58:07 +01:00
Ben Horgan
eda1cd1f9d KVM: arm64: Preserve host MPAM configuration when changing traps
When KVM enables or disables MPAM traps to EL2 it clears all other bits in
MPAM2_EL2.  Notably, it clears the partition ids (PARTIDs) and performance
monitoring groups (PMGs). Avoid changing these bits in anticipation of
adding support for MPAM in the kernel. Otherwise, on a VHE system with the
host running at EL2 where MPAM2_EL2 and MPAM1_EL1 access the same register,
any attempt to use MPAM to monitor or partition resources for kernel space
would be foiled by running a KVM guest. Additionally, MPAM2_EL2.EnMPAMSM is
always set to 0 which causes MPAMSM_EL1 to always trap. Keep EnMPAMSM set
to 1 when not in a guest so that the kernel can use MPAMSM_EL1.

Tested-by: Gavin Shan <gshan@redhat.com>
Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Tested-by: Peter Newman <peternewman@google.com>
Tested-by: Zeng Heng <zengheng4@huawei.com>
Tested-by: Punit Agrawal <punit.agrawal@oss.qualcomm.com>
Tested-by: Jesse Chick <jessechick@os.amperecomputing.com>
Reviewed-by: Zeng Heng <zengheng4@huawei.com>
Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Ben Horgan <ben.horgan@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
2026-03-27 15:27:32 +00:00
Sascha Bischoff
9d6d9514c0 KVM: arm64: gic-v5: Support GICv5 FGTs & FGUs
Extend the existing FGT/FGU infrastructure to include the GICv5 trap
registers (ICH_HFGRTR_EL2, ICH_HFGWTR_EL2, ICH_HFGITR_EL2). This
involves mapping the trap registers and their bits to the
corresponding feature that introduces them (FEAT_GCIE for all, in this
case), and mapping each trap bit to the system register/instruction
controlled by it.

As of this change, none of the GICv5 instructions or register accesses
are being trapped.

Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Link: https://patch.msgid.link/20260319154937.3619520-14-sascha.bischoff@arm.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-03-19 18:21:27 +00:00
Vincent Donnefort
696dfec22b KVM: arm64: Add hyp_enter/hyp_exit events to nVHE/pKVM hyp
The hyp_enter and hyp_exit events are logged by the hypervisor any time
it is entered and exited.

Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Link: https://patch.msgid.link/20260309162516.2623589-29-vdonnefort@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-03-11 08:51:17 +00:00