KVM: PPC: PV instructions to loads and stores

Some instructions can simply be replaced by load and store instructions to
or from the magic page.

This patch replaces often called instructions that fall into the above category.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 109 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/kvm.c b/arch/powerpc/kernel/kvm.c
index e93366fbbd21..9ec572c4d2a5 100644
--- a/arch/powerpc/kernel/kvm.c
+++ b/arch/powerpc/kernel/kvm.c
@@ -33,7 +33,34 @@
 #define KVM_MAGIC_PAGE          (-4096L)
 #define magic_var(x) KVM_MAGIC_PAGE + offsetof(struct kvm_vcpu_arch_shared, x)
 
+#define KVM_INST_LWZ            0x80000000
+#define KVM_INST_STW            0x90000000
+#define KVM_INST_LD             0xe8000000
+#define KVM_INST_STD            0xf8000000
+#define KVM_INST_NOP            0x60000000
+#define KVM_INST_B              0x48000000
+#define KVM_INST_B_MASK         0x03ffffff
+#define KVM_INST_B_MAX          0x01ffffff
+
 #define KVM_MASK_RT             0x03e00000
+#define KVM_INST_MFMSR          0x7c0000a6
+#define KVM_INST_MFSPR_SPRG0    0x7c1042a6
+#define KVM_INST_MFSPR_SPRG1    0x7c1142a6
+#define KVM_INST_MFSPR_SPRG2    0x7c1242a6
+#define KVM_INST_MFSPR_SPRG3    0x7c1342a6
+#define KVM_INST_MFSPR_SRR0     0x7c1a02a6
+#define KVM_INST_MFSPR_SRR1     0x7c1b02a6
+#define KVM_INST_MFSPR_DAR      0x7c1302a6
+#define KVM_INST_MFSPR_DSISR    0x7c1202a6
+
+#define KVM_INST_MTSPR_SPRG0    0x7c1043a6
+#define KVM_INST_MTSPR_SPRG1    0x7c1143a6
+#define KVM_INST_MTSPR_SPRG2    0x7c1243a6
+#define KVM_INST_MTSPR_SPRG3    0x7c1343a6
+#define KVM_INST_MTSPR_SRR0     0x7c1a03a6
+#define KVM_INST_MTSPR_SRR1     0x7c1b03a6
+#define KVM_INST_MTSPR_DAR      0x7c1303a6
+#define KVM_INST_MTSPR_DSISR    0x7c1203a6
 
 static bool kvm_patching_worked = true;
 
@@ -43,6 +70,34 @@ static inline void kvm_patch_ins(u32 *inst, u32 new_inst)
         flush_icache_range((ulong)inst, (ulong)inst + 4);
 }
 
+static void kvm_patch_ins_ld(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 + 4) & 0x0000fffc));
+#endif
+}
+
+static void kvm_patch_ins_lwz(u32 *inst, long addr, u32 rt)
+{
+        kvm_patch_ins(inst, KVM_INST_LWZ | rt | (addr & 0x0000ffff));
+}
+
+static void kvm_patch_ins_std(u32 *inst, long addr, u32 rt)
+{
+#ifdef CONFIG_64BIT
+        kvm_patch_ins(inst, KVM_INST_STD | rt | (addr & 0x0000fffc));
+#else
+        kvm_patch_ins(inst, KVM_INST_STW | rt | ((addr + 4) & 0x0000fffc));
+#endif
+}
+
+static void kvm_patch_ins_stw(u32 *inst, long addr, u32 rt)
+{
+        kvm_patch_ins(inst, KVM_INST_STW | rt | (addr & 0x0000fffc));
+}
+
 static void kvm_map_magic_page(void *data)
 {
         kvm_hypercall2(KVM_HC_PPC_MAP_MAGIC_PAGE,
@@ -57,6 +112,60 @@ static void kvm_check_ins(u32 *inst)
         u32 inst_rt = _inst & KVM_MASK_RT;
 
         switch (inst_no_rt) {
+        /* Loads */
+        case KVM_INST_MFMSR:
+                kvm_patch_ins_ld(inst, magic_var(msr), inst_rt);
+                break;
+        case KVM_INST_MFSPR_SPRG0:
+                kvm_patch_ins_ld(inst, magic_var(sprg0), inst_rt);
+                break;
+        case KVM_INST_MFSPR_SPRG1:
+                kvm_patch_ins_ld(inst, magic_var(sprg1), inst_rt);
+                break;
+        case KVM_INST_MFSPR_SPRG2:
+                kvm_patch_ins_ld(inst, magic_var(sprg2), inst_rt);
+                break;
+        case KVM_INST_MFSPR_SPRG3:
+                kvm_patch_ins_ld(inst, magic_var(sprg3), inst_rt);
+                break;
+        case KVM_INST_MFSPR_SRR0:
+                kvm_patch_ins_ld(inst, magic_var(srr0), inst_rt);
+                break;
+        case KVM_INST_MFSPR_SRR1:
+                kvm_patch_ins_ld(inst, magic_var(srr1), inst_rt);
+                break;
+        case KVM_INST_MFSPR_DAR:
+                kvm_patch_ins_ld(inst, magic_var(dar), inst_rt);
+                break;
+        case KVM_INST_MFSPR_DSISR:
+                kvm_patch_ins_lwz(inst, magic_var(dsisr), inst_rt);
+                break;
+
+        /* Stores */
+        case KVM_INST_MTSPR_SPRG0:
+                kvm_patch_ins_std(inst, magic_var(sprg0), inst_rt);
+                break;
+        case KVM_INST_MTSPR_SPRG1:
+                kvm_patch_ins_std(inst, magic_var(sprg1), inst_rt);
+                break;
+        case KVM_INST_MTSPR_SPRG2:
+                kvm_patch_ins_std(inst, magic_var(sprg2), inst_rt);
+                break;
+        case KVM_INST_MTSPR_SPRG3:
+                kvm_patch_ins_std(inst, magic_var(sprg3), inst_rt);
+                break;
+        case KVM_INST_MTSPR_SRR0:
+                kvm_patch_ins_std(inst, magic_var(srr0), inst_rt);
+                break;
+        case KVM_INST_MTSPR_SRR1:
+                kvm_patch_ins_std(inst, magic_var(srr1), inst_rt);
+                break;
+        case KVM_INST_MTSPR_DAR:
+                kvm_patch_ins_std(inst, magic_var(dar), inst_rt);
+                break;
+        case KVM_INST_MTSPR_DSISR:
+                kvm_patch_ins_stw(inst, magic_var(dsisr), inst_rt);
+                break;
         }
 
         switch (_inst) {