[PATCH v3 2/5] KVM: arm64: nv: Inject SEA if kvm_translate_vncr() can't resolve PFN
From: Oliver Upton <oupton@kernel.org>
Date: 2026-06-18 23:42:12
Also in:
kvmarm
Subsystem:
arm64 port (aarch64 architecture), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Marc Zyngier, Oliver Upton, Linus Torvalds
kvm_handle_vncr_abort() assumes that s1_walk_result conveys an abort
when kvm_translate_vncr() returns -EFAULT. This is not always the case
as it's possible to encounter 'late' failures on the output of S1
translation, e.g. a GFN outside of the memslots.
Fix it by preparing an external abort before returning from
kvm_translate_vncr(). Get rid of the BUG_ON() in the fault injection
path while at it.
Cc: stable@vger.kernel.org
Fixes: 2a359e072596 ("KVM: arm64: nv: Handle mapping of VNCR_EL2 at EL2")
Signed-off-by: Oliver Upton <oupton@kernel.org>
---
arch/arm64/include/asm/kvm_nested.h | 8 ++++++++
arch/arm64/kvm/at.c | 8 --------
arch/arm64/kvm/nested.c | 10 ++++++----
3 files changed, 14 insertions(+), 12 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_nested.h b/arch/arm64/include/asm/kvm_nested.h
index dc2957662ff2..cbdaaa2a2903 100644
--- a/arch/arm64/include/asm/kvm_nested.h
+++ b/arch/arm64/include/asm/kvm_nested.h@@ -388,6 +388,14 @@ struct s1_walk_result { bool failed; }; +static inline void fail_s1_walk(struct s1_walk_result *wr, u8 fst, bool s1ptw) +{ + wr->fst = fst; + wr->ptw = s1ptw; + wr->s2 = s1ptw; + wr->failed = true; +} + int __kvm_translate_va(struct kvm_vcpu *vcpu, struct s1_walk_info *wi, struct s1_walk_result *wr, u64 va); int __kvm_find_s1_desc_level(struct kvm_vcpu *vcpu, u64 va, u64 ipa,
diff --git a/arch/arm64/kvm/at.c b/arch/arm64/kvm/at.c
index 30e6fa8ac07c..8263c648207b 100644
--- a/arch/arm64/kvm/at.c
+++ b/arch/arm64/kvm/at.c@@ -11,14 +11,6 @@ #include <asm/kvm_mmu.h> #include <asm/lsui.h> -static void fail_s1_walk(struct s1_walk_result *wr, u8 fst, bool s1ptw) -{ - wr->fst = fst; - wr->ptw = s1ptw; - wr->s2 = s1ptw; - wr->failed = true; -} - #define S1_MMU_DISABLED (-127) static int get_ia_size(struct s1_walk_info *wi)
diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c
index 903ccabca78c..53dea9c3f14f 100644
--- a/arch/arm64/kvm/nested.c
+++ b/arch/arm64/kvm/nested.c@@ -1395,15 +1395,19 @@ static int kvm_translate_vncr(struct kvm_vcpu *vcpu, bool *is_gmem) gfn = vt->wr.pa >> PAGE_SHIFT; memslot = gfn_to_memslot(vcpu->kvm, gfn); - if (!memslot) + if (!memslot) { + fail_s1_walk(&vt->wr, ESR_ELx_FSC_EXTABT, false); return -EFAULT; + } *is_gmem = kvm_slot_has_gmem(memslot); if (!*is_gmem) { pfn = __kvm_faultin_pfn(memslot, gfn, write_fault ? FOLL_WRITE : 0, &writable, &page); - if (is_error_noslot_pfn(pfn)) + if (is_error_noslot_pfn(pfn)) { + fail_s1_walk(&vt->wr, ESR_ELx_FSC_EXTABT, false); return -EFAULT; + } } else { ret = kvm_gmem_get_pfn(vcpu->kvm, memslot, gfn, &pfn, &page, NULL); if (ret) {
@@ -1530,8 +1534,6 @@ int kvm_handle_vncr_abort(struct kvm_vcpu *vcpu) * Translation failed, inject the corresponding * exception back to EL2. */ - BUG_ON(!vt->wr.failed); - esr &= ~ESR_ELx_FSC; esr |= FIELD_PREP(ESR_ELx_FSC, vt->wr.fst);
--
2.47.3