[PATCH v3 2/3] KVM: s390: vsie: Do the CRYCB validation first

[Pierre Morel]

When entering the SIE the CRYCB validation better
be done independently of the instruction's
availability.

Signed-off-by: Pierre Morel <pmorel@xxxxxxxxxxxxx>
---
 arch/s390/kvm/vsie.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c
index 12b9707..38ea5da 100644
--- a/arch/s390/kvm/vsie.c
+++ b/arch/s390/kvm/vsie.c
@@ -161,17 +161,18 @@ static int shadow_crycb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
 	/* format-1 is supported with message-security-assist extension 3 */
 	if (!test_kvm_facility(vcpu->kvm, 76))
 		return 0;
-	/* we may only allow it if enabled for guest 2 */
-	ecb3_flags = scb_o->ecb3 & vcpu->arch.sie_block->ecb3 &
-		     (ECB3_AES | ECB3_DEA);
-	if (!ecb3_flags)
-		return 0;
 
 	if ((crycb_addr & PAGE_MASK) != ((crycb_addr + 128) & PAGE_MASK))
 		return set_validity_icpt(scb_s, 0x003CU);
 	else if (!crycb_addr)
 		return set_validity_icpt(scb_s, 0x0039U);
 
+	/* we may only allow it if enabled for guest 2 */
+	ecb3_flags = scb_o->ecb3 & vcpu->arch.sie_block->ecb3 &
+		     (ECB3_AES | ECB3_DEA);
+	if (!ecb3_flags)
+		return 0;
+
 	/* copy only the wrapping keys */
 	if (read_guest_real(vcpu, crycb_addr + 72,
 			    vsie_page->crycb.dea_wrapping_key_mask, 56))
-- 
2.7.4