KVM: s390: gs support for kvm guests

This patch adds guarded storage support for KVM guest. We need to
setup the necessary control blocks, the kvm_run structure for the
new registers, the necessary wrappers for VSIE, as well as the
machine check save areas.
GS is enabled lazily and the register saving and reloading is done in
KVM code.  As this feature adds new content for migration, we provide
a new capability for enablement (KVM_CAP_S390_GS).

Signed-off-by: Fan Zhang <zhangfan@linux.vnet.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

1 files changed, 13 insertions, 1 deletions

diff --git a/arch/s390/include/uapi/asm/kvm.h b/arch/s390/include/uapi/asm/kvm.h
index a2ffec4139ad..5bd23cfd9ae5 100644
--- a/arch/s390/include/uapi/asm/kvm.h
+++ b/arch/s390/include/uapi/asm/kvm.h
@@ -197,6 +197,10 @@ struct kvm_guest_debug_arch {
 #define KVM_SYNC_VRS    (1UL << 6)
 #define KVM_SYNC_RICCB  (1UL << 7)
 #define KVM_SYNC_FPRS   (1UL << 8)
+#define KVM_SYNC_GSCB   (1UL << 9)
+/* length and alignment of the sdnx as a power of two */
+#define SDNXC 8
+#define SDNXL (1UL << SDNXC)
 /* definition of registers in kvm_run */
 struct kvm_sync_regs {
 	__u64 prefix;	/* prefix register */
@@ -217,8 +221,16 @@ struct kvm_sync_regs {
 	};
 	__u8  reserved[512];	/* for future vector expansion */
 	__u32 fpc;		/* valid on KVM_SYNC_VRS or KVM_SYNC_FPRS */
-	__u8 padding[52];	/* riccb needs to be 64byte aligned */
+	__u8 padding1[52];	/* riccb needs to be 64byte aligned */
 	__u8 riccb[64];		/* runtime instrumentation controls block */
+	__u8 padding2[192];	/* sdnx needs to be 256byte aligned */
+	union {
+		__u8 sdnx[SDNXL];  /* state description annex */
+		struct {
+			__u64 reserved1[2];
+			__u64 gscb[4];
+		};
+	};
 };
 
 #define KVM_REG_S390_TODPR	(KVM_REG_S390 | KVM_REG_SIZE_U32 | 0x1)