KVM: PPC: Book3S: Add GET/SET_ONE_REG interface for VRSAVE

The VRSAVE register value for a vcpu is accessible through the
GET/SET_SREGS interface for Book E processors, but not for Book 3S
processors.  In order to make this accessible for Book 3S processors,
this adds a new register identifier for GET/SET_ONE_REG, and adds
the code to implement it.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>

3 files changed, 13 insertions, 0 deletions

diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index e43c6f14c225..26fc37355dcb 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -1834,6 +1834,7 @@ registers, find a list below:
   PPC   | KVM_REG_PPC_TCSCR     | 64
   PPC   | KVM_REG_PPC_PID       | 64
   PPC   | KVM_REG_PPC_ACOP      | 64
+  PPC   | KVM_REG_PPC_VRSAVE    | 32
   PPC   | KVM_REG_PPC_TM_GPR0   | 64
           ...
   PPC   | KVM_REG_PPC_TM_GPR31  | 64
diff --git a/arch/powerpc/include/uapi/asm/kvm.h b/arch/powerpc/include/uapi/asm/kvm.h
index a8124fe93fb9..b98bf3f50527 100644
--- a/arch/powerpc/include/uapi/asm/kvm.h
+++ b/arch/powerpc/include/uapi/asm/kvm.h
@@ -532,6 +532,8 @@ struct kvm_get_htab_header {
 #define KVM_REG_PPC_PID         (KVM_REG_PPC | KVM_REG_SIZE_U64 | 0xb2)
 #define KVM_REG_PPC_ACOP        (KVM_REG_PPC | KVM_REG_SIZE_U64 | 0xb3)
 
+#define KVM_REG_PPC_VRSAVE      (KVM_REG_PPC | KVM_REG_SIZE_U32 | 0xb4)
+
 /* Transactional Memory checkpointed state:
  * This is all GPRs, all VSX regs and a subset of SPRs
  */
diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index 700df6f1d32c..f97369dc457c 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -528,6 +528,9 @@ int kvm_vcpu_ioctl_get_one_reg(struct kvm_vcpu *vcpu, struct kvm_one_reg *reg)
                         }
                         val = get_reg_val(reg->id, vcpu->arch.vscr.u[3]);
                         break;
+                case KVM_REG_PPC_VRSAVE:
+                        val = get_reg_val(reg->id, vcpu->arch.vrsave);
+                        break;
 #endif /* CONFIG_ALTIVEC */
                 case KVM_REG_PPC_DEBUG_INST: {
                         u32 opcode = INS_TW;
@@ -605,6 +608,13 @@ int kvm_vcpu_ioctl_set_one_reg(struct kvm_vcpu *vcpu, struct kvm_one_reg *reg)
                         }
                         vcpu->arch.vscr.u[3] = set_reg_val(reg->id, val);
                         break;
+                case KVM_REG_PPC_VRSAVE:
+                        if (!cpu_has_feature(CPU_FTR_ALTIVEC)) {
+                                r = -ENXIO;
+                                break;
+                        }
+                        vcpu->arch.vrsave = set_reg_val(reg->id, val);
+                        break;
 #endif /* CONFIG_ALTIVEC */
 #ifdef CONFIG_KVM_XICS
                 case KVM_REG_PPC_ICP_STATE: