[Qemu-devel] Re: [PATCH 09/10] Add savevm/loadvm support for MCE

[Anthony Liguori]

On 10/20/2010 12:43 PM, Marcelo Tosatti wrote:
Port qemu-kvm's
commit 1bab5d11545d8de5facf46c28630085a2f9651ae
Author: Huang Ying<ying.hu...@intel.com>
Date:   Wed Mar 3 16:52:46 2010 +0800

     Add savevm/loadvm support for MCE

     MCE registers are saved/load into/from CPUState in
     kvm_arch_save/load_regs. To simulate the MCG_STATUS clearing upon
     reset, MSR_MCG_STATUS is set to 0 for KVM_PUT_RESET_STATE.

Signed-off-by: Marcelo Tosatti<mtosa...@redhat.com>
Signed-off-by: Avi Kivity<a...@redhat.com>
---
  target-i386/kvm.c |   39 ++++++++++++++++++++++++++++++++++++++-
  1 files changed, 38 insertions(+), 1 deletions(-)

diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index 8e26bc4..1701cb9 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -777,7 +777,7 @@ static int kvm_put_msrs(CPUState *env, int level)
          struct kvm_msr_entry entries[100];
      } msr_data;
      struct kvm_msr_entry *msrs = msr_data.entries;
-    int n = 0;
+    int i, n = 0;

      kvm_msr_entry_set(&msrs[n++], MSR_IA32_SYSENTER_CS, env->sysenter_cs);
      kvm_msr_entry_set(&msrs[n++], MSR_IA32_SYSENTER_ESP, env->sysenter_esp);
@@ -797,6 +797,18 @@ static int kvm_put_msrs(CPUState *env, int level)
                            env->system_time_msr);
          kvm_msr_entry_set(&msrs[n++], MSR_KVM_WALL_CLOCK, 
env->wall_clock_msr);
      }
+#ifdef KVM_CAP_MCE
+    if (env->mcg_cap) {
+        if (level == KVM_PUT_RESET_STATE)
+            kvm_msr_entry_set(&msrs[n++], MSR_MCG_STATUS, env->mcg_status);
+        else if (level == KVM_PUT_FULL_STATE) {
+            kvm_msr_entry_set(&msrs[n++], MSR_MCG_STATUS, env->mcg_status);
+            kvm_msr_entry_set(&msrs[n++], MSR_MCG_CTL, env->mcg_ctl);
+            for (i = 0; i<  (env->mcg_cap&  0xff) * 4; i++)
+                kvm_msr_entry_set(&msrs[n++], MSR_MC0_CTL + i, 
env->mce_banks[i]);
+        }
+    }
+#endif
   

What happens if we live migration from a kernel with KVM_CAP_MCE to a 
kernel without KVM_CAP_MCE.  Don't we need to bump a version somewhere?

      msr_data.info.nmsrs = n;

@@ -1004,6 +1016,15 @@ static int kvm_get_msrs(CPUState *env)
      msrs[n++].index = MSR_KVM_SYSTEM_TIME;
      msrs[n++].index = MSR_KVM_WALL_CLOCK;

+#ifdef KVM_CAP_MCE
+    if (env->mcg_cap) {
+        msrs[n++].index = MSR_MCG_STATUS;
+        msrs[n++].index = MSR_MCG_CTL;
+        for (i = 0; i<  (env->mcg_cap&  0xff) * 4; i++)
+            msrs[n++].index = MSR_MC0_CTL + i;
+    }
+#endif
+
   

This patch does not respect CODING_STYLE with respect to single line ifs 
at all.

Regards,

Anthony Liguori

      msr_data.info.nmsrs = n;
      ret = kvm_vcpu_ioctl(env, KVM_GET_MSRS,&msr_data);
      if (ret<  0)
@@ -1046,6 +1067,22 @@ static int kvm_get_msrs(CPUState *env)
          case MSR_KVM_WALL_CLOCK:
              env->wall_clock_msr = msrs[i].data;
              break;
+#ifdef KVM_CAP_MCE
+        case MSR_MCG_STATUS:
+            env->mcg_status = msrs[i].data;
+            break;
+        case MSR_MCG_CTL:
+            env->mcg_ctl = msrs[i].data;
+            break;
+#endif
+        default:
+#ifdef KVM_CAP_MCE
+            if (msrs[i].index>= MSR_MC0_CTL&&
+                msrs[i].index<  MSR_MC0_CTL + (env->mcg_cap&  0xff) * 4) {
+                env->mce_banks[msrs[i].index - MSR_MC0_CTL] = msrs[i].data;
+                break;
+            }
+#endif
          }
      }