From: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
This simplifies the code and also stops issuing warning about writing to
unhandled MSRs when VMX is disabled or the Feature Control MSR is
locked - we do handle them all according to the spec.
Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
---
arch/x86/include/uapi/asm/msr-index.h | 1 +
arch/x86/kvm/vmx.c | 79 ++++++++++-------------------------
2 files changed, 24 insertions(+), 56 deletions(-)
diff --git a/arch/x86/include/uapi/asm/msr-index.h b/arch/x86/include/uapi/asm/msr-index.h
index 37813b5..2e4a42d 100644
--- a/arch/x86/include/uapi/asm/msr-index.h
+++ b/arch/x86/include/uapi/asm/msr-index.h
@@ -527,6 +527,7 @@
#define MSR_IA32_VMX_TRUE_PROCBASED_CTLS 0x0000048e
#define MSR_IA32_VMX_TRUE_EXIT_CTLS 0x0000048f
#define MSR_IA32_VMX_TRUE_ENTRY_CTLS 0x00000490
+#define MSR_IA32_VMX_VMFUNC 0x00000491
/* VMX_BASIC bits and bitmasks */
#define VMX_BASIC_VMCS_SIZE_SHIFT 32
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 9cd6eb7..36efd47 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2361,32 +2361,10 @@ static inline u64 vmx_control_msr(u32 low, u32 high)
return low | ((u64)high << 32);
}
-/*
- * If we allow our guest to use VMX instructions (i.e., nested VMX), we should
- * also let it use VMX-specific MSRs.
- * vmx_get_vmx_msr() and vmx_set_vmx_msr() return 1 when we handled a
- * VMX-specific MSR, or 0 when we haven't (and the caller should handle it
- * like all other MSRs).
- */
+/* Returns 0 on success, non-0 otherwise. */
static int vmx_get_vmx_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata)
{
- if (!nested_vmx_allowed(vcpu) && msr_index >= MSR_IA32_VMX_BASIC &&
- msr_index <= MSR_IA32_VMX_TRUE_ENTRY_CTLS) {
- /*
- * According to the spec, processors which do not support VMX
- * should throw a #GP(0) when VMX capability MSRs are read.
- */
- kvm_queue_exception_e(vcpu, GP_VECTOR, 0);
- return 1;
- }
-
switch (msr_index) {
- case MSR_IA32_FEATURE_CONTROL:
- if (nested_vmx_allowed(vcpu)) {
- *pdata = to_vmx(vcpu)->nested.msr_ia32_feature_control;
- break;
- }
- return 0;
case MSR_IA32_VMX_BASIC:
/*
* This MSR reports some information about VMX support. We
@@ -2453,38 +2431,9 @@ static int vmx_get_vmx_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata)
*pdata = nested_vmx_ept_caps;
break;
default:
- return 0;
- }
-
- return 1;
-}
-
-static void vmx_leave_nested(struct kvm_vcpu *vcpu);
-
-static int vmx_set_vmx_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
-{
- u32 msr_index = msr_info->index;
- u64 data = msr_info->data;
- bool host_initialized = msr_info->host_initiated;
-
- if (!nested_vmx_allowed(vcpu))
- return 0;
-
- if (msr_index == MSR_IA32_FEATURE_CONTROL) {
- if (!host_initialized &&
- to_vmx(vcpu)->nested.msr_ia32_feature_control
- & FEATURE_CONTROL_LOCKED)
- return 0;
- to_vmx(vcpu)->nested.msr_ia32_feature_control = data;
- if (host_initialized && data == 0)
- vmx_leave_nested(vcpu);
return 1;
}
- /*
- * No need to treat VMX capability MSRs specially: If we don't handle
- * them, handle_wrmsr will #GP(0), which is correct (they are readonly)
- */
return 0;
}
@@ -2530,13 +2479,20 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata)
case MSR_IA32_SYSENTER_ESP:
data = vmcs_readl(GUEST_SYSENTER_ESP);
break;
+ case MSR_IA32_FEATURE_CONTROL:
+ if (!nested_vmx_allowed(vcpu))
+ return 1;
+ data = to_vmx(vcpu)->nested.msr_ia32_feature_control;
+ break;
+ case MSR_IA32_VMX_BASIC ... MSR_IA32_VMX_VMFUNC:
+ if (!nested_vmx_allowed(vcpu))
+ return 1;
+ return vmx_get_vmx_msr(vcpu, msr_index, pdata);
case MSR_TSC_AUX:
if (!to_vmx(vcpu)->rdtscp_enabled)
return 1;
/* Otherwise falls through */
default:
- if (vmx_get_vmx_msr(vcpu, msr_index, pdata))
- return 0;
msr = find_msr_entry(to_vmx(vcpu), msr_index);
if (msr) {
data = msr->data;
@@ -2549,6 +2505,8 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata)
return 0;
}
+static void vmx_leave_nested(struct kvm_vcpu *vcpu);
+
/*
* Writes msr value into into the appropriate "register".
* Returns 0 on success, non-0 otherwise.
@@ -2603,6 +2561,17 @@ 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_FEATURE_CONTROL:
+ if (!nested_vmx_allowed(vcpu) ||
+ (to_vmx(vcpu)->nested.msr_ia32_feature_control &
+ FEATURE_CONTROL_LOCKED && !msr_info->host_initiated))
+ return 1;
+ vmx->nested.msr_ia32_feature_control = data;
+ if (msr_info->host_initiated && data == 0)
+ vmx_leave_nested(vcpu);
+ break;
+ case MSR_IA32_VMX_BASIC ... MSR_IA32_VMX_VMFUNC:
+ return 1; /* they are read-only */
case MSR_TSC_AUX:
if (!vmx->rdtscp_enabled)
return 1;
@@ -2611,8 +2580,6 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
return 1;
/* Otherwise falls through */
default:
- if (vmx_set_vmx_msr(vcpu, msr_info))
- break;
msr = find_msr_entry(vmx, msr_index);
if (msr) {
msr->data = data;
--
1.8.1.1.298.ge7eed54
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