[PATCH v8 14/22] KVM: s390: interfaces to clear CRYCB masks

[Tony Krowiak <akrowiak@linux.vnet.ibm.com>]

From: Tony Krowiak <akrowiak@linux.ibm.com>

Introduces two new KVM interface to clear the APM, AQM and ADM masks in
the guest's CRYCB.  The VCPUs are taken out of SIE to ensure the VCPUs do
not get out of sync.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Acked-by: Halil Pasic <pasic@linux.ibm.com>
Tested-by: Michael Mueller <mimu@linux.ibm.com>
Tested-by: Farhan Ali <alifm@linux.ibm.com>
Tested-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
---
 arch/s390/include/asm/kvm_host.h |    3 +++
 arch/s390/kvm/kvm-s390.c         |   15 +++++++++++++++
 2 files changed, 18 insertions(+), 0 deletions(-)

diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index 0c13f61..d7e19e1 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -258,6 +258,7 @@ struct kvm_s390_sie_block {
 	__u64	tecmc;			/* 0x00e8 */
 	__u8	reservedf0[12];		/* 0x00f0 */
 #define CRYCB_FORMAT_MASK 0x00000003
+#define CRYCB_FORMAT0 0x00000000
 #define CRYCB_FORMAT1 0x00000001
 #define CRYCB_FORMAT2 0x00000003
 	__u32	crycbd;			/* 0x00fc */
@@ -862,6 +863,8 @@ 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 f96a443..0d03249 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -1919,6 +1919,21 @@ 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(kvm_arch_crypto_clear_masks);
+
 static u64 kvm_s390_get_initial_cpuid(void)
 {
 	struct cpuid cpuid;
-- 
1.7.1