| From foo@baz Mon Feb 5 10:12:24 PST 2018 |
| Subject: KVM/VMX: Emulate MSR_IA32_ARCH_CAPABILITIES |
| From: KarimAllah Ahmed karahmed@amazon.de |
| Date: Thu Feb 1 22:59:44 2018 +0100 |
| |
| From: KarimAllah Ahmed karahmed@amazon.de |
| |
| commit 28c1c9fabf48d6ad596273a11c46e0d0da3e14cd |
| |
| 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] |
| |
| Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de> |
| Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> |
| Signed-off-by: Thomas Gleixner <tglx@linutronix.de> |
| Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> |
| Reviewed-by: Darren Kenny <darren.kenny@oracle.com> |
| Reviewed-by: Jim Mattson <jmattson@google.com> |
| Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> |
| Cc: Andrea Arcangeli <aarcange@redhat.com> |
| Cc: Andi Kleen <ak@linux.intel.com> |
| Cc: Jun Nakajima <jun.nakajima@intel.com> |
| Cc: kvm@vger.kernel.org |
| Cc: Dave Hansen <dave.hansen@intel.com> |
| Cc: Linus Torvalds <torvalds@linux-foundation.org> |
| Cc: Andy Lutomirski <luto@kernel.org> |
| Cc: Asit Mallick <asit.k.mallick@intel.com> |
| Cc: Arjan Van De Ven <arjan.van.de.ven@intel.com> |
| Cc: Greg KH <gregkh@linuxfoundation.org> |
| Cc: Dan Williams <dan.j.williams@intel.com> |
| Cc: Tim Chen <tim.c.chen@linux.intel.com> |
| Cc: Ashok Raj <ashok.raj@intel.com> |
| Link: https://lkml.kernel.org/r/1517522386-18410-4-git-send-email-karahmed@amazon.de |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| |
| --- |
| 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(-) |
| |
| --- a/arch/x86/kvm/cpuid.c |
| +++ b/arch/x86/kvm/cpuid.c |
| @@ -394,7 +394,7 @@ static inline int __do_cpuid_ent(struct |
| |
| /* 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(); |
| --- a/arch/x86/kvm/vmx.c |
| +++ b/arch/x86/kvm/vmx.c |
| @@ -583,6 +583,8 @@ 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; |
| @@ -3257,6 +3259,12 @@ static int vmx_get_msr(struct kvm_vcpu * |
| 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; |
| @@ -3392,6 +3400,11 @@ static int vmx_set_msr(struct kvm_vcpu * |
| 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)) |
| @@ -5652,6 +5665,8 @@ static int vmx_vcpu_setup(struct vcpu_vm |
| ++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); |
| |
| --- a/arch/x86/kvm/x86.c |
| +++ b/arch/x86/kvm/x86.c |
| @@ -1006,6 +1006,7 @@ 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; |