From: Marc Zyngier Date: Sun, 17 Aug 2025 20:21:55 +0000 (+0100) Subject: KVM: arm64: Ignore HCR_EL2.FIEN set by L1 guest's EL2 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=9049fb1227a2d1ab8515788c8553232966380248;p=users%2Fjedix%2Flinux-maple.git KVM: arm64: Ignore HCR_EL2.FIEN set by L1 guest's EL2 An EL2 guest can set HCR_EL2.FIEN, which gives access to the RASv1p1 fault injection mechanism. This would allow an EL1 guest to inject error records into the system, which does sound like a terrible idea. Prevent this situation by added FIEN to the list of bits we silently exclude from being inserted into the host configuration. Signed-off-by: Marc Zyngier Reviewed-by: Joey Gouly Link: https://lore.kernel.org/r/20250817202158.395078-4-maz@kernel.org Signed-off-by: Oliver Upton --- diff --git a/arch/arm64/kvm/hyp/vhe/switch.c b/arch/arm64/kvm/hyp/vhe/switch.c index e482181c66322..0998ad4a25524 100644 --- a/arch/arm64/kvm/hyp/vhe/switch.c +++ b/arch/arm64/kvm/hyp/vhe/switch.c @@ -43,8 +43,11 @@ DEFINE_PER_CPU(unsigned long, kvm_hyp_vector); * * - API/APK: they are already accounted for by vcpu_load(), and can * only take effect across a load/put cycle (such as ERET) + * + * - FIEN: no way we let a guest have access to the RAS "Common Fault + * Injection" thing, whatever that does */ -#define NV_HCR_GUEST_EXCLUDE (HCR_TGE | HCR_API | HCR_APK) +#define NV_HCR_GUEST_EXCLUDE (HCR_TGE | HCR_API | HCR_APK | HCR_FIEN) static u64 __compute_hcr(struct kvm_vcpu *vcpu) {