KVM: s390: sync of fp registers via kvm_run
As we already store the floating point registers in the vector save area
in floating point register format when we don't have MACHINE_HAS_VX, we can
directly expose them to user space using a new sync flag.
The floating point registers will be valid when KVM_SYNC_FPRS is set. The
fpc will also be valid when KVM_SYNC_FPRS is set.
Either KVM_SYNC_FPRS or KVM_SYNC_VRS will be enabled, never both.
Let's also change two positions where we access vrs, making the code easier
to read and one comment superfluous.
Suggested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
diff --git a/arch/s390/include/uapi/asm/kvm.h b/arch/s390/include/uapi/asm/kvm.h
index fe84bd5..347fe5a 100644
--- a/arch/s390/include/uapi/asm/kvm.h
+++ b/arch/s390/include/uapi/asm/kvm.h
@@ -154,6 +154,7 @@
#define KVM_SYNC_PFAULT (1UL << 5)
#define KVM_SYNC_VRS (1UL << 6)
#define KVM_SYNC_RICCB (1UL << 7)
+#define KVM_SYNC_FPRS (1UL << 8)
/* definition of registers in kvm_run */
struct kvm_sync_regs {
__u64 prefix; /* prefix register */
@@ -168,9 +169,12 @@
__u64 pft; /* pfault token [PFAULT] */
__u64 pfs; /* pfault select [PFAULT] */
__u64 pfc; /* pfault compare [PFAULT] */
- __u64 vrs[32][2]; /* vector registers */
+ union {
+ __u64 vrs[32][2]; /* vector registers (KVM_SYNC_VRS) */
+ __u64 fprs[16]; /* fp registers (KVM_SYNC_FPRS) */
+ };
__u8 reserved[512]; /* for future vector expansion */
- __u32 fpc; /* only valid with vector registers */
+ __u32 fpc; /* valid on KVM_SYNC_VRS or KVM_SYNC_FPRS */
__u8 padding[52]; /* riccb needs to be 64byte aligned */
__u8 riccb[64]; /* runtime instrumentation controls block */
};