[Qemu-devel] [PATCH 3/5] kvm: make hyperv hypercall and guest os id MSRs migratable.

[Paolo Bonzini <pbonzini@redhat.com>]

From: Vadim Rozenfeld <vrozenfe@redhat.com>

Signed-off-by: Vadim Rozenfeld <vrozenfe@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 target-i386/cpu.h     |  2 ++
 target-i386/kvm.c     | 18 +++++++++++++++---
 target-i386/machine.c | 23 +++++++++++++++++++++++
 3 files changed, 40 insertions(+), 3 deletions(-)

diff --git a/target-i386/cpu.h b/target-i386/cpu.h
index 1fcbc82..3dba5ef 100644
--- a/target-i386/cpu.h
+++ b/target-i386/cpu.h
@@ -862,6 +862,8 @@ typedef struct CPUX86State {
     uint64_t msr_fixed_counters[MAX_FIXED_COUNTERS];
     uint64_t msr_gp_counters[MAX_GP_COUNTERS];
     uint64_t msr_gp_evtsel[MAX_GP_COUNTERS];
+    uint64_t msr_hv_hypercall;
+    uint64_t msr_hv_guest_os_id;
 
     /* exception/interrupt handling */
     int error_code;
diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index 08c47bb..8f2854a 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -1227,9 +1227,11 @@ static int kvm_put_msrs(X86CPU *cpu, int level)
             kvm_msr_entry_set(&msrs[n++], MSR_CORE_PERF_GLOBAL_CTRL,
                               env->msr_global_ctrl);
         }
-        if (hyperv_hypercall_available(cpu)) {
-            kvm_msr_entry_set(&msrs[n++], HV_X64_MSR_GUEST_OS_ID, 0);
-            kvm_msr_entry_set(&msrs[n++], HV_X64_MSR_HYPERCALL, 0);
+        if (has_msr_hv_hypercall) {
+            kvm_msr_entry_set(&msrs[n++], HV_X64_MSR_GUEST_OS_ID,
+                              env->msr_hv_guest_os_id);
+            kvm_msr_entry_set(&msrs[n++], HV_X64_MSR_HYPERCALL,
+                              env->msr_hv_hypercall);
         }
         if (cpu->hyperv_vapic) {
             kvm_msr_entry_set(&msrs[n++], HV_X64_MSR_APIC_ASSIST_PAGE, 0);
@@ -1518,6 +1520,10 @@ static int kvm_get_msrs(X86CPU *cpu)
         }
     }
 
+    if (has_msr_hv_hypercall) {
+        msrs[n++].index = HV_X64_MSR_HYPERCALL;
+        msrs[n++].index = HV_X64_MSR_GUEST_OS_ID;
+    }
     msr_data.info.nmsrs = n;
     ret = kvm_vcpu_ioctl(CPU(cpu), KVM_GET_MSRS, &msr_data);
     if (ret < 0) {
@@ -1625,6 +1631,12 @@ static int kvm_get_msrs(X86CPU *cpu)
         case MSR_P6_EVNTSEL0 ... MSR_P6_EVNTSEL0 + MAX_GP_COUNTERS - 1:
             env->msr_gp_evtsel[index - MSR_P6_EVNTSEL0] = msrs[i].data;
             break;
+        case HV_X64_MSR_HYPERCALL:
+            env->msr_hv_hypercall = msrs[i].data;
+            break;
+        case HV_X64_MSR_GUEST_OS_ID:
+            env->msr_hv_guest_os_id = msrs[i].data;
+            break;
         }
     }
 
diff --git a/target-i386/machine.c b/target-i386/machine.c
index 2de1964..96fd045 100644
--- a/target-i386/machine.c
+++ b/target-i386/machine.c
@@ -554,6 +554,26 @@ static const VMStateDescription vmstate_mpx = {
     }
 };
 
+static bool hyperv_hypercall_enable_needed(void *opaque)
+{
+    X86CPU *cpu = opaque;
+    CPUX86State *env = &cpu->env;
+
+    return env->msr_hv_hypercall != 0 || env->msr_hv_guest_os_id != 0;
+}
+
+static const VMStateDescription vmstate_msr_hypercall_hypercall = {
+    .name = "cpu/msr_hyperv_hypercall",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .minimum_version_id_old = 1,
+    .fields      = (VMStateField []) {
+        VMSTATE_UINT64(env.msr_hv_hypercall, X86CPU),
+        VMSTATE_UINT64(env.msr_hv_guest_os_id, X86CPU),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
 const VMStateDescription vmstate_x86_cpu = {
     .name = "cpu",
     .version_id = 12,
@@ -688,6 +708,9 @@ const VMStateDescription vmstate_x86_cpu = {
         } , {
             .vmsd = &vmstate_mpx,
             .needed = mpx_needed,
+        }, {
+            .vmsd = &vmstate_msr_hypercall_hypercall,
+            .needed = hyperv_hypercall_enable_needed,
         } , {
             /* empty */
         }
-- 
1.8.3.1