kernel/linux.git/arch/arm64/include/asm/kvm_pgtable.h, branch linux-7.1.y

KVM: arm64: Introduce hypercall to force reclaim of a protected page

2026-03-30T15:58:09+00:00

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 Tested-by: Mostafa Saleh Signed-off-by: Will Deacon Link: https://patch.msgid.link/20260330144841.26181-26-will@kernel.org Signed-off-by: Marc Zyngier

KVM: arm64: Introduce host_stage2_set_owner_metadata_locked()

2026-03-30T15:58:08+00:00

Rework host_stage2_set_owner_locked() to add a new helper function, host_stage2_set_owner_metadata_locked(), which will allow us to store additional metadata alongside a 3-bit owner ID for invalid host stage-2 entries. Tested-by: Fuad Tabba Tested-by: Mostafa Saleh Signed-off-by: Will Deacon Link: https://patch.msgid.link/20260330144841.26181-23-will@kernel.org Signed-off-by: Marc Zyngier

KVM: arm64: Generalise kvm_pgtable_stage2_set_owner()

2026-03-30T15:58:08+00:00

kvm_pgtable_stage2_set_owner() can be generalised into a way to store up to 59 bits in the page tables alongside a 4-bit 'type' identifier specific to the format of the 59-bit payload. Introduce kvm_pgtable_stage2_annotate() and move the existing invalid ptes (for locked ptes and donated pages) over to the new scheme. Tested-by: Fuad Tabba Tested-by: Mostafa Saleh Signed-off-by: Will Deacon Link: https://patch.msgid.link/20260330144841.26181-22-will@kernel.org Signed-off-by: Marc Zyngier

KVM: arm64: Introduce __pkvm_host_donate_guest()

2026-03-30T15:58:08+00:00

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 Tested-by: Mostafa Saleh Signed-off-by: Will Deacon Link: https://patch.msgid.link/20260330144841.26181-13-will@kernel.org Signed-off-by: Marc Zyngier

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