1 files changed, 32 insertions, 7 deletions

diff --git a/arch/powerpc/kernel/kvm.c b/arch/powerpc/kernel/kvm.c
index c8bab24ff8a..10b681c092e 100644
--- a/arch/powerpc/kernel/kvm.c
+++ b/arch/powerpc/kernel/kvm.c
@@ -42,6 +42,7 @@
 #define KVM_INST_B_MAX          0x01ffffff
 
 #define KVM_MASK_RT             0x03e00000
+#define KVM_RT_30               0x03c00000
 #define KVM_MASK_RB             0x0000f800
 #define KVM_INST_MFMSR          0x7c0000a6
 #define KVM_INST_MFSPR_SPRG0    0x7c1042a6
@@ -82,6 +83,15 @@ static inline void kvm_patch_ins(u32 *inst, u32 new_inst)
         flush_icache_range((ulong)inst, (ulong)inst + 4);
 }
 
+static void kvm_patch_ins_ll(u32 *inst, long addr, u32 rt)
+{
+#ifdef CONFIG_64BIT
+        kvm_patch_ins(inst, KVM_INST_LD | rt | (addr & 0x0000fffc));
+#else
+        kvm_patch_ins(inst, KVM_INST_LWZ | rt | (addr & 0x0000fffc));
+#endif
+}
+
 static void kvm_patch_ins_ld(u32 *inst, long addr, u32 rt)
 {
 #ifdef CONFIG_64BIT
@@ -186,7 +196,6 @@ static void kvm_patch_ins_mtmsrd(u32 *inst, u32 rt)
 extern u32 kvm_emulate_mtmsr_branch_offs;
 extern u32 kvm_emulate_mtmsr_reg1_offs;
 extern u32 kvm_emulate_mtmsr_reg2_offs;
-extern u32 kvm_emulate_mtmsr_reg3_offs;
 extern u32 kvm_emulate_mtmsr_orig_ins_offs;
 extern u32 kvm_emulate_mtmsr_len;
 extern u32 kvm_emulate_mtmsr[];
@@ -216,9 +225,27 @@ static void kvm_patch_ins_mtmsr(u32 *inst, u32 rt)
         /* Modify the chunk to fit the invocation */
         memcpy(p, kvm_emulate_mtmsr, kvm_emulate_mtmsr_len * 4);
         p[kvm_emulate_mtmsr_branch_offs] |= distance_end & KVM_INST_B_MASK;
-        p[kvm_emulate_mtmsr_reg1_offs] |= rt;
-        p[kvm_emulate_mtmsr_reg2_offs] |= rt;
-        p[kvm_emulate_mtmsr_reg3_offs] |= rt;
+
+        /* Make clobbered registers work too */
+        switch (get_rt(rt)) {
+        case 30:
+                kvm_patch_ins_ll(&p[kvm_emulate_mtmsr_reg1_offs],
+                                 magic_var(scratch2), KVM_RT_30);
+                kvm_patch_ins_ll(&p[kvm_emulate_mtmsr_reg2_offs],
+                                 magic_var(scratch2), KVM_RT_30);
+                break;
+        case 31:
+                kvm_patch_ins_ll(&p[kvm_emulate_mtmsr_reg1_offs],
+                                 magic_var(scratch1), KVM_RT_30);
+                kvm_patch_ins_ll(&p[kvm_emulate_mtmsr_reg2_offs],
+                                 magic_var(scratch1), KVM_RT_30);
+                break;
+        default:
+                p[kvm_emulate_mtmsr_reg1_offs] |= rt;
+                p[kvm_emulate_mtmsr_reg2_offs] |= rt;
+                break;
+        }
+
         p[kvm_emulate_mtmsr_orig_ins_offs] = *inst;
         flush_icache_range((ulong)p, (ulong)p + kvm_emulate_mtmsr_len * 4);
 
@@ -402,9 +429,7 @@ static void kvm_check_ins(u32 *inst, u32 features)
                 break;
         case KVM_INST_MTMSR:
         case KVM_INST_MTMSRD_L0:
-                /* We use r30 and r31 during the hook */
-                if (get_rt(inst_rt) < 30)
-                        kvm_patch_ins_mtmsr(inst, inst_rt);
+                kvm_patch_ins_mtmsr(inst, inst_rt);
                 break;
         }