On Intel platforms, this patch adds LMCE to KVM MCE supported
capabilities and handles guest access to LMCE related MSRs.
Signed-off-by: Ashok Raj <ashok....@intel.com>
Signed-off-by: Haozhong Zhang <haozhong.zh...@intel.com>
---
arch/x86/include/asm/kvm_host.h | 3 +++
arch/x86/kvm/vmx.c | 27 +++++++++++++++++++++++++--
arch/x86/kvm/x86.c | 12 ++++++------
3 files changed, 34 insertions(+), 8 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index e0fbe7e..89509f9d 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -598,6 +598,7 @@ struct kvm_vcpu_arch {
u64 mcg_cap;
u64 mcg_status;
u64 mcg_ctl;
+ u64 mcg_ext_ctl;
u64 *mce_banks;
/* Cache MMIO info */
@@ -1077,6 +1078,8 @@ extern u8 kvm_tsc_scaling_ratio_frac_bits;
/* maximum allowed value of TSC scaling ratio */
extern u64 kvm_max_tsc_scaling_ratio;
+extern u64 kvm_mce_cap_supported;
+
enum emulation_result {
EMULATE_DONE, /* no further processing */
EMULATE_USER_EXIT, /* kvm_run ready for userspace exit */
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index fb93010..42c3ee1 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2863,6 +2863,11 @@ static int vmx_get_vmx_msr(struct kvm_vcpu *vcpu, u32
msr_index, u64 *pdata)
return 0;
}
+static inline bool vmx_feature_control_msr_required(struct kvm_vcpu *vcpu)
+{
+ return nested_vmx_allowed(vcpu) || (vcpu->arch.mcg_cap & MCG_LMCE_P);
+}
+
/*
* Reads an msr value (of 'msr_index') into 'pdata'.
* Returns 0 on success, non-0 otherwise.
@@ -2904,8 +2909,15 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct
msr_data *msr_info)
return 1;
msr_info->data = vmcs_read64(GUEST_BNDCFGS);
break;
+ case MSR_IA32_MCG_EXT_CTL:
+ if (!(vcpu->arch.mcg_cap & MCG_LMCE_P) ||
+ !(to_vmx(vcpu)->nested.msr_ia32_feature_control &
+ FEATURE_CONTROL_LMCE))
+ return 1;
+ msr_info->data = vcpu->arch.mcg_ext_ctl;
+ break;
case MSR_IA32_FEATURE_CONTROL:
- if (!nested_vmx_allowed(vcpu))
+ if (!vmx_feature_control_msr_required(vcpu))
return 1;
msr_info->data = to_vmx(vcpu)->nested.msr_ia32_feature_control;
break;
@@ -2997,8 +3009,17 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct
msr_data *msr_info)
case MSR_IA32_TSC_ADJUST:
ret = kvm_set_msr_common(vcpu, msr_info);
break;
+ case MSR_IA32_MCG_EXT_CTL:
+ if (!(vcpu->arch.mcg_cap & MCG_LMCE_P) ||
+ !(to_vmx(vcpu)->nested.msr_ia32_feature_control &
+ FEATURE_CONTROL_LMCE))
+ return 1;
+ if (data && data != 0x1)
+ return -1;
+ vcpu->arch.mcg_ext_ctl = data;
+ break;
case MSR_IA32_FEATURE_CONTROL:
- if (!nested_vmx_allowed(vcpu) ||
+ if (!vmx_feature_control_msr_required(vcpu) ||
(to_vmx(vcpu)->nested.msr_ia32_feature_control &
FEATURE_CONTROL_LOCKED && !msr_info->host_initiated))
return 1;
@@ -6391,6 +6412,8 @@ static __init int hardware_setup(void)
kvm_set_posted_intr_wakeup_handler(wakeup_handler);
+ kvm_mce_cap_supported |= MCG_LMCE_P;
+
return alloc_kvm_area();
out8:
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 902d9da..0cc8f00 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -70,7 +70,8 @@
#define MAX_IO_MSRS 256
#define KVM_MAX_MCE_BANKS 32
-#define KVM_MCE_CAP_SUPPORTED (MCG_CTL_P | MCG_SER_P)
+u64 __read_mostly kvm_mce_cap_supported = MCG_CTL_P | MCG_SER_P;
+EXPORT_SYMBOL_GPL(kvm_mce_cap_supported);
#define emul_to_vcpu(ctxt) \
container_of(ctxt, struct kvm_vcpu, arch.emulate_ctxt)
@@ -982,6 +983,7 @@ static u32 emulated_msrs[] = {
MSR_IA32_MISC_ENABLE,
MSR_IA32_MCG_STATUS,
MSR_IA32_MCG_CTL,
+ MSR_IA32_MCG_EXT_CTL,
MSR_IA32_SMBASE,
};
@@ -2683,11 +2685,9 @@ long kvm_arch_dev_ioctl(struct file *filp,
break;
}
case KVM_X86_GET_MCE_CAP_SUPPORTED: {
- u64 mce_cap;
-
- mce_cap = KVM_MCE_CAP_SUPPORTED;
r = -EFAULT;
- if (copy_to_user(argp, &mce_cap, sizeof mce_cap))
+ if (copy_to_user(argp, &kvm_mce_cap_supported,
+ sizeof(kvm_mce_cap_supported)))
goto out;
r = 0;
break;
@@ -2865,7 +2865,7 @@ static int kvm_vcpu_ioctl_x86_setup_mce(struct kvm_vcpu
*vcpu,
r = -EINVAL;
if (!bank_num || bank_num >= KVM_MAX_MCE_BANKS)
goto out;
- if (mcg_cap & ~(KVM_MCE_CAP_SUPPORTED | 0xff | 0xff0000))
+ if (mcg_cap & ~(kvm_mce_cap_supported | 0xff | 0xff0000))
goto out;
r = 0;
vcpu->arch.mcg_cap = mcg_cap;
--
2.8.3
