From: Pierre Morel <pmorel@linux.ibm.com>
Date: Fri, 26 Apr 2019 10:56:50 +0200
Subject: KVM: s390: vsie: Do not shadow CRYCB when no AP and no keys
Git-commit: bcccb8f6a91b50fde008354fa8273dd14829dce2
Patch-mainline: v5.2-rc1
References: git-fixes

When the guest do not have AP instructions nor Key management
we should return without shadowing the CRYCB.

We did not check correctly in the past.

Fixes: b10bd9a256ae ("s390: vsie: Use effective CRYCBD.31 to check CRYCBD validity")
Fixes: 6ee74098201b ("KVM: s390: vsie: allow CRYCB FORMAT-0")

Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
Message-Id: <1556269010-22258-1-git-send-email-pmorel@linux.ibm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 arch/s390/kvm/vsie.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/arch/s390/kvm/vsie.c
+++ b/arch/s390/kvm/vsie.c
@@ -284,6 +284,7 @@ static int shadow_crycb(struct kvm_vcpu
 	u8 ecb3_flags;
 	u32 ecd_flags;
 	int apie_h;
+	int apie_s;
 	int key_msk = test_kvm_facility(vcpu->kvm, 76);
 	int fmt_o = crycbd_o & CRYCB_FORMAT_MASK;
 	int fmt_h = vcpu->arch.sie_block->crycbd & CRYCB_FORMAT_MASK;
@@ -292,7 +293,8 @@ static int shadow_crycb(struct kvm_vcpu
 	scb_s->crycbd = 0;
 
 	apie_h = vcpu->arch.sie_block->eca & ECA_APIE;
-	if (!apie_h && (!key_msk || fmt_o == CRYCB_FORMAT0))
+	apie_s = apie_h & scb_o->eca;
+	if (!apie_s && (!key_msk || (fmt_o == CRYCB_FORMAT0)))
 		return 0;
 
 	if (!crycb_addr)
@@ -303,7 +305,7 @@ static int shadow_crycb(struct kvm_vcpu
 		    ((crycb_addr + 128) & PAGE_MASK))
 			return set_validity_icpt(scb_s, 0x003CU);
 
-	if (apie_h && (scb_o->eca & ECA_APIE)) {
+	if (apie_s) {
 		ret = setup_apcb(vcpu, &vsie_page->crycb, crycb_addr,
 				 vcpu->kvm->arch.crypto.crycb,
 				 fmt_o, fmt_h);