i386: Add support for SPEC_CTRL MSR

Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Message-Id: <20180109154519.25634-3-ehabkost@redhat.com>
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>

target/i386/cpu.h

@@ -353,6 +353,7 @@ typedef enum X86Seg {
 #define MSR_IA32_APICBASE_BASE          (0xfffffU<<12)
 #define MSR_IA32_FEATURE_CONTROL        0x0000003a
 #define MSR_TSC_ADJUST                  0x0000003b
+#define MSR_IA32_SPEC_CTRL              0x48
 #define MSR_IA32_TSCDEADLINE            0x6e0
 
 #define FEATURE_CONTROL_LOCKED                    (1<<0)
@@ -1125,6 +1126,8 @@ typedef struct CPUX86State {
 
     uint32_t pkru;
 
+    uint64_t spec_ctrl;
+
     /* End of state preserved by INIT (dummy marker).  */
     struct {} end_init_save;
 

target/i386/kvm.c

@@ -91,6 +91,7 @@ static bool has_msr_hv_synic;
 static bool has_msr_hv_stimer;
 static bool has_msr_hv_frequencies;
 static bool has_msr_xss;
+static bool has_msr_spec_ctrl;
 
 static uint32_t has_architectural_pmu_version;
 static uint32_t num_architectural_pmu_gp_counters;
@@ -1153,6 +1154,9 @@ static int kvm_get_supported_msrs(KVMState *s)
                 case HV_X64_MSR_TSC_FREQUENCY:
                     has_msr_hv_frequencies = true;
                     break;
+                case MSR_IA32_SPEC_CTRL:
+                    has_msr_spec_ctrl = true;
+                    break;
                 }
             }
         }
@@ -1635,6 +1639,9 @@ static int kvm_put_msrs(X86CPU *cpu, int level)
     if (has_msr_xss) {
         kvm_msr_entry_add(cpu, MSR_IA32_XSS, env->xss);
     }
+    if (has_msr_spec_ctrl) {
+        kvm_msr_entry_add(cpu, MSR_IA32_SPEC_CTRL, env->spec_ctrl);
+    }
 #ifdef TARGET_X86_64
     if (lm_capable_kernel) {
         kvm_msr_entry_add(cpu, MSR_CSTAR, env->cstar);
@@ -1643,6 +1650,7 @@ static int kvm_put_msrs(X86CPU *cpu, int level)
         kvm_msr_entry_add(cpu, MSR_LSTAR, env->lstar);
     }
 #endif
+
     /*
      * The following MSRs have side effects on the guest or are too heavy
      * for normal writeback. Limit them to reset or full state updates.
@@ -1980,6 +1988,9 @@ static int kvm_get_msrs(X86CPU *cpu)
     if (has_msr_xss) {
         kvm_msr_entry_add(cpu, MSR_IA32_XSS, 0);
     }
+    if (has_msr_spec_ctrl) {
+        kvm_msr_entry_add(cpu, MSR_IA32_SPEC_CTRL, 0);
+    }
 
 
     if (!env->tsc_valid) {
@@ -2327,6 +2338,9 @@ static int kvm_get_msrs(X86CPU *cpu)
                 env->mtrr_var[MSR_MTRRphysIndex(index)].base = msrs[i].data;
             }
             break;
+        case MSR_IA32_SPEC_CTRL:
+            env->spec_ctrl = msrs[i].data;
+            break;
         }
     }
 

target/i386/machine.c

@@ -818,6 +818,25 @@ static const VMStateDescription vmstate_mcg_ext_ctl = {
     }
 };
 
+static bool spec_ctrl_needed(void *opaque)
+{
+    X86CPU *cpu = opaque;
+    CPUX86State *env = &cpu->env;
+
+    return env->spec_ctrl != 0;
+}
+
+static const VMStateDescription vmstate_spec_ctrl = {
+    .name = "cpu/spec_ctrl",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .needed = spec_ctrl_needed,
+    .fields = (VMStateField[]){
+        VMSTATE_UINT64(env.spec_ctrl, X86CPU),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
 VMStateDescription vmstate_x86_cpu = {
     .name = "cpu",
     .version_id = 12,
@@ -936,6 +955,7 @@ VMStateDescription vmstate_x86_cpu = {
 #ifdef TARGET_X86_64
         &vmstate_pkru,
 #endif
+        &vmstate_spec_ctrl,
         &vmstate_mcg_ext_ctl,
         NULL
     }