[PATCH v8 19/22] KVM: s390: Clear Crypto Control Block when using vSIE

[Tony Krowiak]

From: Pierre Morel <pmorel@xxxxxxxxxxxxx>

When we clear the Crypto Control Block (CRYCB) used by a guest
level 2, the vSIE shadow CRYCB for guest level 3 must be updated
before the guest uses it.

We achieve this by using the KVM_REQ_VSIE_RESTART synchronous
request for each vCPU belonging to the guest to force the reload
of the shadow CRYCB before rerunning the guest level 3.

Signed-off-by: Pierre Morel <pmorel@xxxxxxxxxxxxx>
---
 arch/s390/kvm/kvm-s390.c |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 0d03249..9203f0b 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -1921,6 +1921,9 @@ static void kvm_s390_set_crycb_format(struct kvm *kvm)
 
 void kvm_arch_crypto_clear_masks(struct kvm *kvm)
 {
+	int i;
+	struct kvm_vcpu *vcpu;
+
 	mutex_lock(&kvm->lock);
 	kvm_s390_vcpu_block_all(kvm);
 
@@ -1929,6 +1932,10 @@ void kvm_arch_crypto_clear_masks(struct kvm *kvm)
 	memset(&kvm->arch.crypto.crycb->apcb1, 0,
 	       sizeof(kvm->arch.crypto.crycb->apcb1));
 
+	/* recreate the shadow crycb for each vcpu */
+	kvm_for_each_vcpu(i, vcpu, kvm)
+		kvm_s390_sync_request(KVM_REQ_VSIE_RESTART, vcpu);
+
 	kvm_s390_vcpu_unblock_all(kvm);
 	mutex_unlock(&kvm->lock);
 }
-- 
1.7.1