From cae501397a25dc1e88375925c5e93a264d4a55ba Mon Sep 17 00:00:00 2001 From: Jan Kiszka Date: Sat, 4 Jan 2014 18:47:22 +0100 Subject: [PATCH] KVM: nVMX: Clean up handling of VMX-related MSRs 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 Signed-off-by: Paolo Bonzini --- 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 e539c45..fc4a255 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; -- 2.7.4