Commit 9049fb12 authored by Marc Zyngier's avatar Marc Zyngier Committed by Oliver Upton
Browse files

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: default avatarMarc Zyngier <maz@kernel.org>
Reviewed-by: default avatarJoey Gouly <joey.gouly@arm.com>
Link: https://lore.kernel.org/r/20250817202158.395078-4-maz@kernel.org


Signed-off-by: default avatarOliver Upton <oliver.upton@linux.dev>
parent d7b3e23f

arch/arm64/kvm/hyp/vhe/switch.c

+4 −1
Original line number Diff line number Diff line
@@ -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)

{