target-i386: kvm: Add basic Intel LMCE support

This patch adds the support to inject SRAR and SRAO as LMCE, i.e. they
are injected to only one VCPU rather than broadcast to all VCPUs. As KVM
reports LMCE support on Intel platforms, this features is only available
on Intel platforms.

LMCE is disabled by default and can be enabled/disabled by cpu option
'lmce=on/off'.

Signed-off-by: Ashok Raj <ashok.raj@intel.com>
[Haozhong: Enable LMCE only on Intel platforms
           Disable LMCE by default and add a cpu option 'lmce'
           Handle the error if LMCE is enabled w/o host support
           Remove MCG_LMCE_P from MCE_CAP_DEF
           Add migration support for LMCE
           Minor code style changes]
Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>

1 files changed, 33 insertions, 3 deletions

diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index 4193fe1746..93275231ec 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -106,6 +106,8 @@ static int has_xsave;
 static int has_xcrs;
 static int has_pit_state2;
 
+static bool has_msr_mcg_ext_ctl;
+
 static struct kvm_cpuid2 *cpuid_cache;
 
 int kvm_has_pit_state2(void)
@@ -382,10 +384,12 @@ static int kvm_get_mce_cap_supported(KVMState *s, uint64_t *mce_cap,
 
 static void kvm_mce_inject(X86CPU *cpu, hwaddr paddr, int code)
 {
+    CPUState *cs = CPU(cpu);
     CPUX86State *env = &cpu->env;
     uint64_t status = MCI_STATUS_VAL | MCI_STATUS_UC | MCI_STATUS_EN |
                       MCI_STATUS_MISCV | MCI_STATUS_ADDRV | MCI_STATUS_S;
     uint64_t mcg_status = MCG_STATUS_MCIP;
+    int flags = 0;
 
     if (code == BUS_MCEERR_AR) {
         status |= MCI_STATUS_AR | 0x134;
@@ -394,10 +398,19 @@ static void kvm_mce_inject(X86CPU *cpu, hwaddr paddr, int code)
         status |= 0xc0;
         mcg_status |= MCG_STATUS_RIPV;
     }
+
+    flags = cpu_x86_support_mca_broadcast(env) ? MCE_INJECT_BROADCAST : 0;
+    /* We need to read back the value of MSR_EXT_MCG_CTL that was set by the
+     * guest kernel back into env->mcg_ext_ctl.
+     */
+    cpu_synchronize_state(cs);
+    if (env->mcg_ext_ctl & MCG_EXT_CTL_LMCE_EN) {
+        mcg_status |= MCG_STATUS_LMCE;
+        flags = 0;
+    }
+
     cpu_x86_inject_mce(NULL, cpu, 9, status, mcg_status, paddr,
-                       (MCM_ADDR_PHYS << 6) | 0xc,
-                       cpu_x86_support_mca_broadcast(env) ?
-                       MCE_INJECT_BROADCAST : 0);
+                       (MCM_ADDR_PHYS << 6) | 0xc, flags);
 }
 
 static void hardware_memory_error(void)
@@ -883,6 +896,10 @@ int kvm_arch_init_vcpu(CPUState *cs)
 
         unsupported_caps = env->mcg_cap & ~(mcg_cap | MCG_CAP_BANKS_MASK);
         if (unsupported_caps) {
+            if (unsupported_caps & MCG_LMCE_P) {
+                error_report("kvm: LMCE not supported");
+                return -ENOTSUP;
+            }
             error_report("warning: Unsupported MCG_CAP bits: 0x%" PRIx64,
                          unsupported_caps);
         }
@@ -903,6 +920,10 @@ int kvm_arch_init_vcpu(CPUState *cs)
                                   !!(c->ecx & CPUID_EXT_SMX);
     }
 
+    if (env->mcg_cap & MCG_LMCE_P) {
+        has_msr_mcg_ext_ctl = has_msr_feature_control = true;
+    }
+
     c = cpuid_find_entry(&cpuid_data.cpuid, 0x80000007, 0);
     if (c && (c->edx & 1<<8) && invtsc_mig_blocker == NULL) {
         /* for migration */
@@ -1723,6 +1744,9 @@ static int kvm_put_msrs(X86CPU *cpu, int level)
 
         kvm_msr_entry_add(cpu, MSR_MCG_STATUS, env->mcg_status);
         kvm_msr_entry_add(cpu, MSR_MCG_CTL, env->mcg_ctl);
+        if (has_msr_mcg_ext_ctl) {
+            kvm_msr_entry_add(cpu, MSR_MCG_EXT_CTL, env->mcg_ext_ctl);
+        }
         for (i = 0; i < (env->mcg_cap & 0xff) * 4; i++) {
             kvm_msr_entry_add(cpu, MSR_MC0_CTL + i, env->mce_banks[i]);
         }
@@ -2026,6 +2050,9 @@ static int kvm_get_msrs(X86CPU *cpu)
     if (env->mcg_cap) {
         kvm_msr_entry_add(cpu, MSR_MCG_STATUS, 0);
         kvm_msr_entry_add(cpu, MSR_MCG_CTL, 0);
+        if (has_msr_mcg_ext_ctl) {
+            kvm_msr_entry_add(cpu, MSR_MCG_EXT_CTL, 0);
+        }
         for (i = 0; i < (env->mcg_cap & 0xff) * 4; i++) {
             kvm_msr_entry_add(cpu, MSR_MC0_CTL + i, 0);
         }
@@ -2154,6 +2181,9 @@ static int kvm_get_msrs(X86CPU *cpu)
         case MSR_MCG_CTL:
             env->mcg_ctl = msrs[i].data;
             break;
+        case MSR_MCG_EXT_CTL:
+            env->mcg_ext_ctl = msrs[i].data;
+            break;
         case MSR_IA32_MISC_ENABLE:
             env->msr_ia32_misc_enable = msrs[i].data;
             break;