[PATCH 2/3] properly save kvm system time msr registers

[Glauber Costa <glommer@redhat.com>]

Currently, the msrs involved in setting up pvclock are not saved over
migration and/or save/restore. This patch puts their value in special
fields in our CPUState, and deal with them using vmstate.

kvm also has to account for it, by including them in the msr list
for the ioctls.

Signed-off-by: Glauber Costa <glommer@redhat.com>
---
 qemu-kvm-x86.c        |   15 +++++++++++++--
 target-i386/cpu.h     |    4 +++-
 target-i386/machine.c |    3 +++
 3 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/qemu-kvm-x86.c b/qemu-kvm-x86.c
index 475151d..693f5b2 100644
--- a/qemu-kvm-x86.c
+++ b/qemu-kvm-x86.c
@@ -834,6 +834,12 @@ static int get_msr_entry(struct kvm_msr_entry *entry, CPUState *env)
         case MSR_VM_HSAVE_PA:
             env->vm_hsave     = entry->data;
             break;
+        case MSR_KVM_SYSTEM_TIME:
+            env->system_time_msr = entry->data;
+            break;
+        case MSR_KVM_WALL_CLOCK:
+            env->wall_clock_msr = entry->data;
+            break;
         default:
             printf("Warning unknown msr index 0x%x\n", entry->index);
             return 1;
@@ -842,9 +848,9 @@ static int get_msr_entry(struct kvm_msr_entry *entry, CPUState *env)
 }
 
 #ifdef TARGET_X86_64
-#define MSR_COUNT 10
+#define MSR_COUNT 12
 #else
-#define MSR_COUNT 6
+#define MSR_COUNT 8
 #endif
 
 static void set_v8086_seg(struct kvm_segment *lhs, const SegmentCache *rhs)
@@ -1002,6 +1008,8 @@ void kvm_arch_load_regs(CPUState *env)
         set_msr_entry(&msrs[n++], MSR_LSTAR  ,           env->lstar);
     }
 #endif
+    set_msr_entry(&msrs[n++], MSR_KVM_SYSTEM_TIME,  env->system_time_msr);
+    set_msr_entry(&msrs[n++], MSR_KVM_WALL_CLOCK,  env->wall_clock_msr);
 
     rc = kvm_set_msrs(env->kvm_cpu_state.vcpu_ctx, msrs, n);
     if (rc == -1)
@@ -1181,6 +1189,9 @@ void kvm_arch_save_regs(CPUState *env)
         msrs[n++].index = MSR_LSTAR;
     }
 #endif
+    msrs[n++].index = MSR_KVM_SYSTEM_TIME;
+    msrs[n++].index = MSR_KVM_WALL_CLOCK;
+
     rc = kvm_get_msrs(env->kvm_cpu_state.vcpu_ctx, msrs, n);
     if (rc == -1) {
         perror("kvm_get_msrs FAILED");
diff --git a/target-i386/cpu.h b/target-i386/cpu.h
index 278d3e3..4605fd2 100644
--- a/target-i386/cpu.h
+++ b/target-i386/cpu.h
@@ -667,6 +667,8 @@ typedef struct CPUX86State {
     target_ulong fmask;
     target_ulong kernelgsbase;
 #endif
+    uint64_t system_time_msr;
+    uint64_t wall_clock_msr;
 
     uint64_t tsc;
 
@@ -886,7 +888,7 @@ uint64_t cpu_get_tsc(CPUX86State *env);
 #define cpu_signal_handler cpu_x86_signal_handler
 #define cpu_list x86_cpu_list
 
-#define CPU_SAVE_VERSION 11
+#define CPU_SAVE_VERSION 12
 
 /* MMU modes definitions */
 #define MMU_MODE0_SUFFIX _kernel
diff --git a/target-i386/machine.c b/target-i386/machine.c
index 16d9c57..b364936 100644
--- a/target-i386/machine.c
+++ b/target-i386/machine.c
@@ -479,6 +479,9 @@ const VMStateDescription vmstate_cpu = {
         VMSTATE_UINT64_ARRAY_V(mce_banks, CPUState, MCE_BANKS_DEF *4, 10),
         /* rdtscp */
         VMSTATE_UINT64_V(tsc_aux, CPUState, 11),
+        /* KVM pvclock msr */
+        VMSTATE_UINT64_V(system_time_msr, CPUState, 12),
+        VMSTATE_UINT64_V(wall_clock_msr, CPUState, 12),
         VMSTATE_END_OF_LIST()
     }
 };
-- 
1.6.2.2