[PATCH v3 3/3] KVM: VMX: enable guest access to LMCE related MSRs
From: Haozhong Zhang
Date: Wed Jun 22 2016 - 03:00:25 EST
From: Ashok Raj <ashok.raj@xxxxxxxxx>
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.raj@xxxxxxxxx>
[Haozhong: macro KVM_MCE_CAP_SUPPORTED => variable kvm_mce_cap_supported
Only enable LMCE on Intel platform
Check MSR_IA32_FEATURE_CONTROL when handling guest
access to MSR_IA32_MCG_EXT_CTL]
Signed-off-by: Haozhong Zhang <haozhong.zhang@xxxxxxxxx>
---
arch/x86/include/asm/kvm_host.h | 5 +++++
arch/x86/kvm/vmx.c | 29 +++++++++++++++++++++++++++++
arch/x86/kvm/x86.c | 15 +++++++++------
3 files changed, 43 insertions(+), 6 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 360c517..7a628fb 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 */
@@ -1008,6 +1009,8 @@ struct kvm_x86_ops {
int (*set_hv_timer)(struct kvm_vcpu *vcpu, u64 guest_deadline_tsc);
void (*cancel_hv_timer)(struct kvm_vcpu *vcpu);
+
+ void (*setup_mce)(struct kvm_vcpu *vcpu);
};
struct kvm_arch_async_pf {
@@ -1082,6 +1085,8 @@ extern u64 kvm_max_tsc_scaling_ratio;
/* 1ull << kvm_tsc_scaling_ratio_frac_bits */
extern u64 kvm_default_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 0a3ccb0..943609f 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2984,6 +2984,13 @@ 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 (!msr_info->host_initiated &&
+ !(to_vmx(vcpu)->msr_ia32_feature_control &
+ FEATURE_CONTROL_LMCE))
+ return 1;
+ msr_info->data = vcpu->arch.mcg_ext_ctl;
+ break;
case MSR_IA32_FEATURE_CONTROL:
msr_info->data = to_vmx(vcpu)->msr_ia32_feature_control;
break;
@@ -3075,6 +3082,14 @@ 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 ((!msr_info->host_initiated &&
+ !(to_vmx(vcpu)->msr_ia32_feature_control &
+ FEATURE_CONTROL_LMCE)) ||
+ (data & ~MCG_EXT_CTL_LMCE_EN))
+ return 1;
+ vcpu->arch.mcg_ext_ctl = data;
+ break;
case MSR_IA32_FEATURE_CONTROL:
if (!vmx_feature_control_msr_valid(vcpu, data) ||
(to_vmx(vcpu)->msr_ia32_feature_control &
@@ -6484,6 +6499,8 @@ 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:
@@ -11109,6 +11126,16 @@ out:
return ret;
}
+static void vmx_setup_mce(struct kvm_vcpu *vcpu)
+{
+ if (vcpu->arch.mcg_cap & MCG_LMCE_P)
+ to_vmx(vcpu)->msr_ia32_feature_control_valid_bits |=
+ FEATURE_CONTROL_LMCE;
+ else
+ to_vmx(vcpu)->msr_ia32_feature_control_valid_bits &=
+ ~FEATURE_CONTROL_LMCE;
+}
+
static struct kvm_x86_ops vmx_x86_ops = {
.cpu_has_kvm_support = cpu_has_kvm_support,
.disabled_by_bios = vmx_disabled_by_bios,
@@ -11238,6 +11265,8 @@ static struct kvm_x86_ops vmx_x86_ops = {
.set_hv_timer = vmx_set_hv_timer,
.cancel_hv_timer = vmx_cancel_hv_timer,
#endif
+
+ .setup_mce = vmx_setup_mce,
};
static int __init vmx_init(void)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 2992196..0a42fc7 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)
@@ -984,6 +985,7 @@ static u32 emulated_msrs[] = {
MSR_IA32_MISC_ENABLE,
MSR_IA32_MCG_STATUS,
MSR_IA32_MCG_CTL,
+ MSR_IA32_MCG_EXT_CTL,
MSR_IA32_SMBASE,
};
@@ -2685,11 +2687,9 @@ 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;
@@ -2872,7 +2872,7 @@ 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;
@@ -2882,6 +2882,9 @@ static int kvm_vcpu_ioctl_x86_setup_mce(struct kvm_vcpu *vcpu,
/* Init IA32_MCi_CTL to all 1s */
for (bank = 0; bank < bank_num; bank++)
vcpu->arch.mce_banks[bank*4] = ~(u64)0;
+
+ if (kvm_x86_ops->setup_mce)
+ kvm_x86_ops->setup_mce(vcpu);
out:
return r;
}
--
2.9.0