[PATCH v11 10/26] KVM: s390: interfaces to clear CRYCB masks

[Tony Krowiak]

From: Tony Krowiak <akrowiak@xxxxxxxxxxxxx>

Introduces a new KVM function to clear the APCB0 and APCB1 in the guest's
CRYCB. This effectively clears all bits of the APM, AQM and ADM masks
configured for the guest. The VCPUs are taken out of SIE to ensure the
VCPUs do not get out of sync.

Signed-off-by: Tony Krowiak <akrowiak@xxxxxxxxxxxxx>
Acked-by: Halil Pasic <pasic@xxxxxxxxxxxxx>
Tested-by: Michael Mueller <mimu@xxxxxxxxxxxxx>
Tested-by: Farhan Ali <alifm@xxxxxxxxxxxxx>
Tested-by: Pierre Morel <pmorel@xxxxxxxxxxxxx>
---
 arch/s390/include/asm/kvm_host.h |  2 ++
 arch/s390/kvm/kvm-s390.c         | 15 +++++++++++++++
 2 files changed, 17 insertions(+)

diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index 79fa0a3a777f..0a78036a802b 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -859,6 +859,8 @@ void kvm_arch_async_page_not_present(struct kvm_vcpu *vcpu,
 void kvm_arch_async_page_present(struct kvm_vcpu *vcpu,
 				 struct kvm_async_pf *work);
 
+void kvm_arch_crypto_clear_masks(struct kvm *kvm);
+
 extern int sie64a(struct kvm_s390_sie_block *, u64 *);
 extern char sie_exit;
 
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index d62f6d840f8c..75aa5aa4a926 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -2033,6 +2033,21 @@ static void kvm_s390_set_crycb_format(struct kvm *kvm)
 		kvm->arch.crypto.crycbd |= CRYCB_FORMAT1;
 }
 
+void kvm_arch_crypto_clear_masks(struct kvm *kvm)
+{
+	mutex_lock(&kvm->lock);
+	kvm_s390_vcpu_block_all(kvm);
+
+	memset(&kvm->arch.crypto.crycb->apcb0, 0,
+	       sizeof(kvm->arch.crypto.crycb->apcb0));
+	memset(&kvm->arch.crypto.crycb->apcb1, 0,
+	       sizeof(kvm->arch.crypto.crycb->apcb1));
+
+	kvm_s390_vcpu_unblock_all(kvm);
+	mutex_unlock(&kvm->lock);
+}
+EXPORT_SYMBOL_GPL(kvm_arch_crypto_clear_masks);
+
 static u64 kvm_s390_get_initial_cpuid(void)
 {
 	struct cpuid cpuid;
-- 
2.19.0.221.g150f307