From: Oliver Upton Date: Thu, 18 Jun 2026 23:42:05 +0000 (-0700) Subject: KVM: arm64: nv: Inject SEA if guest VNCR isn't normal memory X-Git-Tag: v7.2-rc4~28^2~5^2~9 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4bd7dbe0b2243e6aa735cae4d5e1ff988b30b2a6;p=thirdparty%2Fkernel%2Flinux.git KVM: arm64: nv: Inject SEA if guest VNCR isn't normal memory When constructing an L1 VNCR mapping, KVM unconditionally uses cacheable memory attributes, even if the underlying PFN isn't memory. This gets particularly hairy if the endpoint doesn't support cacheable memory attributes, potentially throwing an SError on writeback... While KVM does permit cacheable memory attributes on certain PFNMAP VMAs, kvm_translate_vncr() isn't currently grabbing the VMA. So do the simpler thing for now and just reject everything that isn't memory. Cc: stable@vger.kernel.org Fixes: 2a359e072596 ("KVM: arm64: nv: Handle mapping of VNCR_EL2 at EL2") Signed-off-by: Oliver Upton Link: https://patch.msgid.link/20260618234207.1063941-5-oupton@kernel.org Signed-off-by: Marc Zyngier --- diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c index 7fffd86eee94..d4c9a9b05e3f 100644 --- a/arch/arm64/kvm/nested.c +++ b/arch/arm64/kvm/nested.c @@ -1419,6 +1419,17 @@ static int kvm_translate_vncr(struct kvm_vcpu *vcpu, bool *is_gmem) writable = !(memslot->flags & KVM_MEM_READONLY); } + /* + * FIXME: This check is too restrictive as KVM allows cacheable memory + * attributes for PFNMAP VMAs that have cacheable attributes in host + * stage-1. + */ + if (!pfn_is_map_memory(pfn)) { + kvm_release_faultin_page(vcpu->kvm, page, true, false); + fail_s1_walk(&vt->wr, ESR_ELx_FSC_EXTABT, false); + return -EINVAL; + } + scoped_guard(write_lock, &vcpu->kvm->mmu_lock) { if (mmu_invalidate_retry(vcpu->kvm, mmu_seq)) { kvm_release_faultin_page(vcpu->kvm, page, true, false);