kernel/linux.git/arch/arm64/include/asm/kvm_pgtable.h, branch linux-7.0.y

Merge branch kvm-arm64/fwb-for-all into kvmarm-master/next

2026-02-05T09:16:42+00:00

* kvm-arm64/fwb-for-all: : . : Allow pKVM's host stage-2 mappings to use the Force Write Back version : of the memory attributes by using the "pass-through' encoding. : : This avoids having two separate encodings for S2 on a given platform. : . KVM: arm64: Simplify PAGE_S2_MEMATTR KVM: arm64: Kill KVM_PGTABLE_S2_NOFWB KVM: arm64: Switch pKVM host S2 over to KVM_PGTABLE_S2_AS_S1 KVM: arm64: Add KVM_PGTABLE_S2_AS_S1 flag arm64: Add MT_S2{,_FWB}_AS_S1 encodings Signed-off-by: Marc Zyngier

KVM: arm64: Kill KVM_PGTABLE_S2_NOFWB

2026-01-25T16:17:21+00:00

Nobody is using this flag anymore, so remove it. This allows some cleanup by removing stage2_has_fwb(), which is can be replaced by a direct check on the capability. Reviewed-by: Joey Gouly Reviewed-by: Fuad Tabba Tested-by: Fuad Tabba Link: https://patch.msgid.link/20260123191637.715429-5-maz@kernel.org Signed-off-by: Marc Zyngier

KVM: arm64: Add KVM_PGTABLE_S2_AS_S1 flag

2026-01-25T16:17:21+00:00

Plumb the MT_S2{,_FWB}_AS_S1 memory types into the KVM_S2_MEMATTR() macro with a new KVM_PGTABLE_S2_AS_S1 flag. Nobody selects it yet. Reviewed-by: Joey Gouly Reviewed-by: Fuad Tabba Tested-by: Fuad Tabba Link: https://patch.msgid.link/20260123191637.715429-3-maz@kernel.org Signed-off-by: Marc Zyngier

KVM: arm64: Honor UX/PX attributes for EL2 S1 mappings

2026-01-15T10:58:21+00:00

Now that we potentially have two bits to deal with when setting execution permissions, make sure we correctly handle them when both when building the page tables and when reading back from them. Reported-by: Alexandru Elisei Reviewed-by: Fuad Tabba Reviewed-by: Joey Gouly Tested-by: Fuad Tabba Link: https://patch.msgid.link/20251210173024.561160-7-maz@kernel.org Signed-off-by: Marc Zyngier

KVM: arm64: Invert KVM_PGTABLE_WALK_HANDLE_FAULT to fix pKVM walkers

2026-01-10T10:19:52+00:00

Commit ddcadb297ce5 ("KVM: arm64: Ignore EAGAIN for walks outside of a fault") introduced a new walker flag ('KVM_PGTABLE_WALK_HANDLE_FAULT') to KVM's page-table code. When set, the walk logic maintains its previous behaviour of terminating a walk as soon as the visitor callback returns an error. However, when the flag is clear, the walk will continue if the visitor returns -EAGAIN and the error is then suppressed and returned as zero to the caller. Clearing the flag is beneficial when write-protecting a range of IPAs with kvm_pgtable_stage2_wrprotect() but is not useful in any other cases, either because we are operating on a single page (e.g. kvm_pgtable_stage2_mkyoung() or kvm_phys_addr_ioremap()) or because the early termination is desirable (e.g. when mapping pages from a fault in user_mem_abort()). Subsequently, commit e912efed485a ("KVM: arm64: Introduce the EL1 pKVM MMU") hooked up pKVM's hypercall interface to the MMU code at EL1 but failed to propagate any of the walker flags. As a result, page-table walks at EL2 fail to set KVM_PGTABLE_WALK_HANDLE_FAULT even when the early termination semantics are desirable on the fault handling path. Rather than complicate the pKVM hypercall interface, invert the flag so that the whole thing can be simplified and only pass the new flag ('KVM_PGTABLE_WALK_IGNORE_EAGAIN') from the wrprotect code. Cc: Fuad Tabba Cc: Quentin Perret Cc: Marc Zyngier Cc: Oliver Upton Reviewed-by: Marc Zyngier Fixes: fce886a60207 ("KVM: arm64: Plumb the pKVM MMU in KVM") Signed-off-by: Will Deacon Reviewed-by: Quentin Perret Link: https://msgid.link/20260105154939.11041-2-will@kernel.org Signed-off-by: Oliver Upton

KVM: arm64: Fix EL2 S1 XN handling for hVHE setups

2026-01-08T20:50:48+00:00

The current XN implementation is tied to the EL2 translation regime, and fall flat on its face with the EL2&0 one that is used for hVHE, as the permission bit for privileged execution is a different one. Fixes: 6537565fd9b7f ("KVM: arm64: Adjust EL2 stage-1 leaf AP bits when ARM64_KVM_HVHE is set") Signed-off-by: Marc Zyngier Reviewed-by: Fuad Tabba Link: https://msgid.link/20251210173024.561160-2-maz@kernel.org Signed-off-by: Oliver Upton

Merge branch 'kvm-arm64/nv-xnx-haf' into kvmarm/next

2025-12-01T08:47:41+00:00

* kvm-arm64/nv-xnx-haf: (22 commits) : Support for FEAT_XNX and FEAT_HAF in nested : : Add support for a couple of MMU-related features that weren't : implemented by KVM's software page table walk: : : - FEAT_XNX: Allows the hypervisor to describe execute permissions : separately for EL0 and EL1 : : - FEAT_HAF: Hardware update of the Access Flag, which in the context of : nested means software walkers must also set the Access Flag. : : The series also adds some basic support for testing KVM's emulation of : the AT instruction, including the implementation detail that AT sets the : Access Flag in KVM. KVM: arm64: at: Update AF on software walk only if VM has FEAT_HAFDBS KVM: arm64: at: Use correct HA bit in TCR_EL2 when regime is EL2 KVM: arm64: Document KVM_PGTABLE_PROT_{UX,PX} KVM: arm64: Fix spelling mistake "Unexpeced" -> "Unexpected" KVM: arm64: Add break to default case in kvm_pgtable_stage2_pte_prot() KVM: arm64: Add endian casting to kvm_swap_s[12]_desc() KVM: arm64: Fix compilation when CONFIG_ARM64_USE_LSE_ATOMICS=n KVM: arm64: selftests: Add test for AT emulation KVM: arm64: nv: Expose hardware access flag management to NV guests KVM: arm64: nv: Implement HW access flag management in stage-2 SW PTW KVM: arm64: Implement HW access flag management in stage-1 SW PTW KVM: arm64: Propagate PTW errors up to AT emulation KVM: arm64: Add helper for swapping guest descriptor KVM: arm64: nv: Use pgtable definitions in stage-2 walk KVM: arm64: Handle endianness in read helper for emulated PTW KVM: arm64: nv: Stop passing vCPU through void ptr in S2 PTW KVM: arm64: Call helper for reading descriptors directly KVM: arm64: nv: Advertise support for FEAT_XNX KVM: arm64: Teach ptdump about FEAT_XNX permissions KVM: arm64: nv: Forward FEAT_XNX permissions to the shadow stage-2 ... Signed-off-by: Oliver Upton

KVM: arm64: Document KVM_PGTABLE_PROT_{UX,PX}

2025-12-01T08:44:03+00:00

Commit 2608563b466b ("KVM: arm64: Add support for FEAT_XNX stage-2 permissions") added the KVM_PGTABLE_PROX_{UX,PX} permissions to stage 2 and to EL2 translation regimes, but left them undocumented. Let's fix that. Signed-off-by: Alexandru Elisei Link: https://msgid.link/20251128100946.74210-2-alexandru.elisei@arm.com Signed-off-by: Oliver Upton

KVM: arm64: Add support for FEAT_XNX stage-2 permissions

2025-11-24T22:24:44+00:00

FEAT_XNX adds support for encoding separate execute permissions for EL0 and EL1 at stage-2. Add support for this to the page table library, hiding the unintuitive encoding scheme behind generic pX and uX permission flags. Reviewed-by: Marc Zyngier Tested-by: Marc Zyngier Link: https://msgid.link/20251124190158.177318-3-oupton@kernel.org Signed-off-by: Oliver Upton

KVM: arm64: Split kvm_pgtable_stage2_destroy()

2025-11-19T22:11:57+00:00

Split kvm_pgtable_stage2_destroy() into two: - kvm_pgtable_stage2_destroy_range(), that performs the page-table walk and free the entries over a range of addresses. - kvm_pgtable_stage2_destroy_pgd(), that frees the PGD. This refactoring enables subsequent patches to free large page-tables in chunks, calling cond_resched() between each chunk, to yield the CPU as necessary. Existing callers of kvm_pgtable_stage2_destroy(), that probably cannot take advantage of this (such as nVMHE), will continue to function as is. Signed-off-by: Raghavendra Rao Ananta Suggested-by: Oliver Upton Link: https://msgid.link/20251113052452.975081-3-rananta@google.com Signed-off-by: Oliver Upton