From: Alexandru Elisei Date: Fri, 28 Nov 2025 10:09:46 +0000 (+0000) Subject: KVM: arm64: at: Update AF on software walk only if VM has FEAT_HAFDBS X-Git-Tag: v6.19-rc1~103^2~1^2^2 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d52aca1635654805a682afef176473793a63b588;p=thirdparty%2Fkernel%2Flinux.git KVM: arm64: at: Update AF on software walk only if VM has FEAT_HAFDBS A guest can write 1 to TCR_ELx.HA, making the KVM software walker update the access flag in a table descriptor even if FEAT_HAFDBS is not present. Avoid this by making wi->ha depend on FEAT_HAFDBS being enabled in the VM, similar to how the software walker treats FEAT_HPDS. This is not needed for VTCR_EL2.HA, since a guest will always write to the in-memory copy of the register, where the HA bit is masked (set to 0) by KVM if the VM doesn't have FEAT_HAFDBS. Fixes: c59ca4b5b0c3 ("KVM: arm64: Implement HW access flag management in stage-1 SW PTW") Signed-off-by: Alexandru Elisei Link: https://msgid.link/20251128100946.74210-5-alexandru.elisei@arm.com Signed-off-by: Oliver Upton --- diff --git a/arch/arm64/kvm/at.c b/arch/arm64/kvm/at.c index 6d41a95f6c60e..53bf70126f81d 100644 --- a/arch/arm64/kvm/at.c +++ b/arch/arm64/kvm/at.c @@ -346,7 +346,8 @@ static int setup_s1_walk(struct kvm_vcpu *vcpu, struct s1_walk_info *wi, wi->baddr &= GENMASK_ULL(wi->max_oa_bits - 1, x); - wi->ha = (wi->regime == TR_EL2 ? + wi->ha = kvm_has_feat(vcpu->kvm, ID_AA64MMFR1_EL1, HAFDBS, AF); + wi->ha &= (wi->regime == TR_EL2 ? FIELD_GET(TCR_EL2_HA, tcr) : FIELD_GET(TCR_HA, tcr));