Re: [PATCH v6 3/5] KVM: VMX: Emulate MSR_IA32_ARCH_CAPABILITIES
On Thu, Feb 01, 2018 at 10:59:44PM +0100, KarimAllah Ahmed wrote: > Intel processors use MSR_IA32_ARCH_CAPABILITIES MSR to indicate RDCL_NO > (bit 0) and IBRS_ALL (bit 1). This is a read-only MSR. By default the > contents will come directly from the hardware, but user-space can still > override it. > > [dwmw2: The bit in kvm_cpuid_7_0_edx_x86_features can be unconditional] > > Cc: Asit Mallick > Cc: Dave Hansen > Cc: Arjan Van De Ven > Cc: Tim Chen > Cc: Linus Torvalds > Cc: Andrea Arcangeli > Cc: Andi Kleen > Cc: Thomas Gleixner > Cc: Dan Williams > Cc: Jun Nakajima > Cc: Andy Lutomirski > Cc: Greg KH > Cc: Paolo Bonzini > Cc: Ashok Raj > Reviewed-by: Paolo Bonzini Reviewed-by: Konrad Rzeszutek Wilk
Re: [PATCH v6 3/5] KVM: VMX: Emulate MSR_IA32_ARCH_CAPABILITIES
On Fri, Feb 2, 2018 at 2:53 AM, Darren Kenny wrote: > On Thu, Feb 01, 2018 at 10:59:44PM +0100, KarimAllah Ahmed wrote: >> >> Intel processors use MSR_IA32_ARCH_CAPABILITIES MSR to indicate RDCL_NO >> (bit 0) and IBRS_ALL (bit 1). This is a read-only MSR. By default the >> contents will come directly from the hardware, but user-space can still >> override it. >> >> [dwmw2: The bit in kvm_cpuid_7_0_edx_x86_features can be unconditional] >> >> Cc: Asit Mallick >> Cc: Dave Hansen >> Cc: Arjan Van De Ven >> Cc: Tim Chen >> Cc: Linus Torvalds >> Cc: Andrea Arcangeli >> Cc: Andi Kleen >> Cc: Thomas Gleixner >> Cc: Dan Williams >> Cc: Jun Nakajima >> Cc: Andy Lutomirski >> Cc: Greg KH >> Cc: Paolo Bonzini >> Cc: Ashok Raj >> Reviewed-by: Paolo Bonzini >> Signed-off-by: KarimAllah Ahmed >> Signed-off-by: David Woodhouse > > > Reviewed-by: Darren Kenny Reviewed-by: Jim Mattson
Re: [PATCH v6 3/5] KVM: VMX: Emulate MSR_IA32_ARCH_CAPABILITIES
On Thu, Feb 01, 2018 at 10:59:44PM +0100, KarimAllah Ahmed wrote: Intel processors use MSR_IA32_ARCH_CAPABILITIES MSR to indicate RDCL_NO (bit 0) and IBRS_ALL (bit 1). This is a read-only MSR. By default the contents will come directly from the hardware, but user-space can still override it. [dwmw2: The bit in kvm_cpuid_7_0_edx_x86_features can be unconditional] Cc: Asit Mallick Cc: Dave Hansen Cc: Arjan Van De Ven Cc: Tim Chen Cc: Linus Torvalds Cc: Andrea Arcangeli Cc: Andi Kleen Cc: Thomas Gleixner Cc: Dan Williams Cc: Jun Nakajima Cc: Andy Lutomirski Cc: Greg KH Cc: Paolo Bonzini Cc: Ashok Raj Reviewed-by: Paolo Bonzini Signed-off-by: KarimAllah Ahmed Signed-off-by: David Woodhouse Reviewed-by: Darren Kenny --- arch/x86/kvm/cpuid.c | 2 +- arch/x86/kvm/vmx.c | 15 +++ arch/x86/kvm/x86.c | 1 + 3 files changed, 17 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 033004d..1909635 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -394,7 +394,7 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, /* cpuid 7.0.edx*/ const u32 kvm_cpuid_7_0_edx_x86_features = - F(AVX512_4VNNIW) | F(AVX512_4FMAPS); + F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(ARCH_CAPABILITIES); /* all calls to cpuid_count() should be made on the same cpu */ get_cpu(); diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 263eb1f..b13314a 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -593,6 +593,8 @@ struct vcpu_vmx { u64 msr_guest_kernel_gs_base; #endif + u64 arch_capabilities; + u32 vm_entry_controls_shadow; u32 vm_exit_controls_shadow; u32 secondary_exec_control; @@ -3262,6 +3264,12 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) case MSR_IA32_TSC: msr_info->data = guest_read_tsc(vcpu); break; + case MSR_IA32_ARCH_CAPABILITIES: + if (!msr_info->host_initiated && + !guest_cpuid_has(vcpu, X86_FEATURE_ARCH_CAPABILITIES)) + return 1; + msr_info->data = to_vmx(vcpu)->arch_capabilities; + break; case MSR_IA32_SYSENTER_CS: msr_info->data = vmcs_read32(GUEST_SYSENTER_CS); break; @@ -3397,6 +3405,11 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) vmx_disable_intercept_for_msr(vmx->vmcs01.msr_bitmap, MSR_IA32_PRED_CMD, MSR_TYPE_W); break; + case MSR_IA32_ARCH_CAPABILITIES: + if (!msr_info->host_initiated) + return 1; + vmx->arch_capabilities = data; + break; case MSR_IA32_CR_PAT: if (vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_PAT) { if (!kvm_mtrr_valid(vcpu, MSR_IA32_CR_PAT, data)) @@ -5659,6 +5672,8 @@ static void vmx_vcpu_setup(struct vcpu_vmx *vmx) ++vmx->nmsrs; } + if (boot_cpu_has(X86_FEATURE_ARCH_CAPABILITIES)) + rdmsrl(MSR_IA32_ARCH_CAPABILITIES, vmx->arch_capabilities); vm_exit_controls_init(vmx, vmcs_config.vmexit_ctrl); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index c53298d..4ec142e 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1009,6 +1009,7 @@ static u32 msrs_to_save[] = { #endif MSR_IA32_TSC, MSR_IA32_CR_PAT, MSR_VM_HSAVE_PA, MSR_IA32_FEATURE_CONTROL, MSR_IA32_BNDCFGS, MSR_TSC_AUX, + MSR_IA32_ARCH_CAPABILITIES }; static unsigned num_msrs_to_save; -- 2.7.4
[PATCH v6 3/5] KVM: VMX: Emulate MSR_IA32_ARCH_CAPABILITIES
Intel processors use MSR_IA32_ARCH_CAPABILITIES MSR to indicate RDCL_NO (bit 0) and IBRS_ALL (bit 1). This is a read-only MSR. By default the contents will come directly from the hardware, but user-space can still override it. [dwmw2: The bit in kvm_cpuid_7_0_edx_x86_features can be unconditional] Cc: Asit Mallick Cc: Dave Hansen Cc: Arjan Van De Ven Cc: Tim Chen Cc: Linus Torvalds Cc: Andrea Arcangeli Cc: Andi Kleen Cc: Thomas Gleixner Cc: Dan Williams Cc: Jun Nakajima Cc: Andy Lutomirski Cc: Greg KH Cc: Paolo Bonzini Cc: Ashok Raj Reviewed-by: Paolo Bonzini Signed-off-by: KarimAllah Ahmed Signed-off-by: David Woodhouse --- arch/x86/kvm/cpuid.c | 2 +- arch/x86/kvm/vmx.c | 15 +++ arch/x86/kvm/x86.c | 1 + 3 files changed, 17 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 033004d..1909635 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -394,7 +394,7 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, /* cpuid 7.0.edx*/ const u32 kvm_cpuid_7_0_edx_x86_features = - F(AVX512_4VNNIW) | F(AVX512_4FMAPS); + F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(ARCH_CAPABILITIES); /* all calls to cpuid_count() should be made on the same cpu */ get_cpu(); diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 263eb1f..b13314a 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -593,6 +593,8 @@ struct vcpu_vmx { u64 msr_guest_kernel_gs_base; #endif + u64 arch_capabilities; + u32 vm_entry_controls_shadow; u32 vm_exit_controls_shadow; u32 secondary_exec_control; @@ -3262,6 +3264,12 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) case MSR_IA32_TSC: msr_info->data = guest_read_tsc(vcpu); break; + case MSR_IA32_ARCH_CAPABILITIES: + if (!msr_info->host_initiated && + !guest_cpuid_has(vcpu, X86_FEATURE_ARCH_CAPABILITIES)) + return 1; + msr_info->data = to_vmx(vcpu)->arch_capabilities; + break; case MSR_IA32_SYSENTER_CS: msr_info->data = vmcs_read32(GUEST_SYSENTER_CS); break; @@ -3397,6 +3405,11 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) vmx_disable_intercept_for_msr(vmx->vmcs01.msr_bitmap, MSR_IA32_PRED_CMD, MSR_TYPE_W); break; + case MSR_IA32_ARCH_CAPABILITIES: + if (!msr_info->host_initiated) + return 1; + vmx->arch_capabilities = data; + break; case MSR_IA32_CR_PAT: if (vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_PAT) { if (!kvm_mtrr_valid(vcpu, MSR_IA32_CR_PAT, data)) @@ -5659,6 +5672,8 @@ static void vmx_vcpu_setup(struct vcpu_vmx *vmx) ++vmx->nmsrs; } + if (boot_cpu_has(X86_FEATURE_ARCH_CAPABILITIES)) + rdmsrl(MSR_IA32_ARCH_CAPABILITIES, vmx->arch_capabilities); vm_exit_controls_init(vmx, vmcs_config.vmexit_ctrl); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index c53298d..4ec142e 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1009,6 +1009,7 @@ static u32 msrs_to_save[] = { #endif MSR_IA32_TSC, MSR_IA32_CR_PAT, MSR_VM_HSAVE_PA, MSR_IA32_FEATURE_CONTROL, MSR_IA32_BNDCFGS, MSR_TSC_AUX, + MSR_IA32_ARCH_CAPABILITIES }; static unsigned num_msrs_to_save; -- 2.7.4