linux-kernel - [PATCH v2 2/5] KVM: s390: vsie: Only accept FORMAT1 CRYCB for guest2

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Date:   Wed, 22 Aug 2018 18:51:54 +0200
From:   Pierre Morel <pmorel@...ux.ibm.com>
To:     david@...hat.com
Cc:     linux-kernel@...r.kernel.org, cohuck@...hat.com,
        linux-s390@...r.kernel.org, kvm@...r.kernel.org,
        frankja@...ux.ibm.com, akrowiak@...ux.ibm.com,
        borntraeger@...ibm.com, schwidefsky@...ibm.com,
        heiko.carstens@...ibm.com
Subject: [PATCH v2 2/5] KVM: s390: vsie: Only accept FORMAT1 CRYCB for guest2

As the comment above the function suggested the shadowing
of the guest2 CRYCB can only accept a format 1 since
AP instructions are not supported in the guest.

Let's modify the check which allowed to accept a format 2 too.

Signed-off-by: Pierre Morel <pmorel@...ux.ibm.com>
---
 arch/s390/kvm/vsie.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c
index 12b9707..56a9d47 100644
--- a/arch/s390/kvm/vsie.c
+++ b/arch/s390/kvm/vsie.c
@@ -156,7 +156,9 @@ static int shadow_crycb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
 	u8 ecb3_flags;
 
 	scb_s->crycbd = 0;
-	if (!(crycbd_o & vcpu->arch.sie_block->crycbd & CRYCB_FORMAT1))
+	if (!(crycbd_o == CRYCB_FORMAT1))
+		return 0;
+	if (!(vcpu->arch.sie_block->crycbd & CRYCB_FORMAT1))
 		return 0;
 	/* format-1 is supported with message-security-assist extension 3 */
 	if (!test_kvm_facility(vcpu->kvm, 76))
-- 
2.7.4