Commit bfb7a30b authored by Oliver Upton's avatar Oliver Upton
Browse files

KVM: arm64: Don't retire MMIO instruction w/ pending (emulated) SError 



KVM might have an emulated SError queued for the guest if userspace
returned an abort for MMIO. Better yet, it could actually be a
*synchronous* exception in disguise if SCTLR2_ELx.EASE is set.

Don't advance PC if KVM owes an emulated SError, just like the handling
of emulated SEA injection.

Reviewed-by: default avatarMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250708172532.1699409-24-oliver.upton@linux.dev


Signed-off-by: default avatarOliver Upton <oliver.upton@linux.dev>
parent a3c4a00d

arch/arm64/kvm/mmio.c

+4 −2
Original line number Diff line number Diff line
@@ -72,7 +72,7 @@ unsigned long kvm_mmio_read_buf(const void *buf, unsigned int len) 
	return data;

}



static bool kvm_pending_sync_exception(struct kvm_vcpu *vcpu)

static bool kvm_pending_external_abort(struct kvm_vcpu *vcpu)

{

	if (!vcpu_get_flag(vcpu, PENDING_EXCEPTION))

		return false;
@@ -90,6 +90,8 @@ static bool kvm_pending_sync_exception(struct kvm_vcpu *vcpu) 
		switch (vcpu_get_flag(vcpu, EXCEPT_MASK)) {

		case unpack_vcpu_flag(EXCEPT_AA64_EL1_SYNC):

		case unpack_vcpu_flag(EXCEPT_AA64_EL2_SYNC):

		case unpack_vcpu_flag(EXCEPT_AA64_EL1_SERR):

		case unpack_vcpu_flag(EXCEPT_AA64_EL2_SERR):

			return true;

		default:

			return false;
@@ -113,7 +115,7 @@ int kvm_handle_mmio_return(struct kvm_vcpu *vcpu) 
	 * Detect if the MMIO return was already handled or if userspace aborted

	 * the MMIO access.

	 */

	if (unlikely(!vcpu->mmio_needed || kvm_pending_sync_exception(vcpu)))

	if (unlikely(!vcpu->mmio_needed || kvm_pending_external_abort(vcpu)))

		return 1;



	vcpu->mmio_needed = 0;