kvm: get/set PV EOI MSR

Support get/set of new PV EOI MSR, for migration.
Add an optional section for MSR value - send it
out in case MSR was changed from the default value (0).
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

target-i386/cpu.h

@@ -699,6 +699,7 @@ typedef struct CPUX86State {
     uint64_t system_time_msr;
     uint64_t wall_clock_msr;
     uint64_t async_pf_en_msr;
+    uint64_t pv_eoi_en_msr;
 
     uint64_t tsc;
     uint64_t tsc_deadline;

target-i386/kvm.c

@@ -63,6 +63,7 @@ static bool has_msr_star;
 static bool has_msr_hsave_pa;
 static bool has_msr_tsc_deadline;
 static bool has_msr_async_pf_en;
+static bool has_msr_pv_eoi_en;
 static bool has_msr_misc_enable;
 static int lm_capable_kernel;
 
@@ -455,6 +456,8 @@ int kvm_arch_init_vcpu(CPUX86State *env)
 
     has_msr_async_pf_en = c->eax & (1 << KVM_FEATURE_ASYNC_PF);
 
+    has_msr_pv_eoi_en = c->eax & (1 << KVM_FEATURE_PV_EOI);
+
     cpu_x86_cpuid(env, 0, 0, &limit, &unused, &unused, &unused);
 
     for (i = 0; i <= limit; i++) {
@@ -1017,6 +1020,10 @@ static int kvm_put_msrs(CPUX86State *env, int level)
             kvm_msr_entry_set(&msrs[n++], MSR_KVM_ASYNC_PF_EN,
                               env->async_pf_en_msr);
         }
+        if (has_msr_pv_eoi_en) {
+            kvm_msr_entry_set(&msrs[n++], MSR_KVM_PV_EOI_EN,
+                              env->pv_eoi_en_msr);
+        }
         if (hyperv_hypercall_available()) {
             kvm_msr_entry_set(&msrs[n++], HV_X64_MSR_GUEST_OS_ID, 0);
             kvm_msr_entry_set(&msrs[n++], HV_X64_MSR_HYPERCALL, 0);
@@ -1259,6 +1266,9 @@ static int kvm_get_msrs(CPUX86State *env)
     if (has_msr_async_pf_en) {
         msrs[n++].index = MSR_KVM_ASYNC_PF_EN;
     }
+    if (has_msr_pv_eoi_en) {
+        msrs[n++].index = MSR_KVM_PV_EOI_EN;
+    }
 
     if (env->mcg_cap) {
         msrs[n++].index = MSR_MCG_STATUS;
@@ -1338,6 +1348,9 @@ static int kvm_get_msrs(CPUX86State *env)
         case MSR_KVM_ASYNC_PF_EN:
             env->async_pf_en_msr = msrs[i].data;
             break;
+        case MSR_KVM_PV_EOI_EN:
+            env->pv_eoi_en_msr = msrs[i].data;
+            break;
         }
     }
 

target-i386/machine.c

@@ -279,6 +279,13 @@ static bool async_pf_msr_needed(void *opaque)
     return cpu->async_pf_en_msr != 0;
 }
 
+static bool pv_eoi_msr_needed(void *opaque)
+{
+    CPUX86State *cpu = opaque;
+
+    return cpu->pv_eoi_en_msr != 0;
+}
+
 static const VMStateDescription vmstate_async_pf_msr = {
     .name = "cpu/async_pf_msr",
     .version_id = 1,
@@ -290,6 +297,17 @@ static const VMStateDescription vmstate_async_pf_msr = {
     }
 };
 
+static const VMStateDescription vmstate_pv_eoi_msr = {
+    .name = "cpu/async_pv_eoi_msr",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .minimum_version_id_old = 1,
+    .fields      = (VMStateField []) {
+        VMSTATE_UINT64(pv_eoi_en_msr, CPUX86State),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
 static bool fpop_ip_dp_needed(void *opaque)
 {
     CPUX86State *env = opaque;
@@ -453,6 +471,9 @@ static const VMStateDescription vmstate_cpu = {
         {
             .vmsd = &vmstate_async_pf_msr,
             .needed = async_pf_msr_needed,
+        } , {
+            .vmsd = &vmstate_pv_eoi_msr,
+            .needed = pv_eoi_msr_needed,
         } , {
             .vmsd = &vmstate_fpop_ip_dp,
             .needed = fpop_ip_dp_needed,