From dc7636423649302a329856f238df8820b9c7dc28 Mon Sep 17 00:00:00 2001 From: KarimAllah Ahmed Date: Thu, 1 Feb 2018 22:59:44 +0100 Subject: [PATCH 21/33] KVM/VMX: Emulate MSR_IA32_ARCH_CAPABILITIES (cherry picked from 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 Signed-off-by: David Woodhouse Signed-off-by: Thomas Gleixner Reviewed-by: Paolo Bonzini Reviewed-by: Darren Kenny Reviewed-by: Jim Mattson Reviewed-by: Konrad Rzeszutek Wilk Cc: Andrea Arcangeli Cc: Andi Kleen Cc: Jun Nakajima Cc: kvm@vger.kernel.org Cc: Dave Hansen Cc: Linus Torvalds Cc: Andy Lutomirski Cc: Asit Mallick Cc: Arjan Van De Ven Cc: Greg KH Cc: Dan Williams Cc: Tim Chen Cc: Ashok Raj Link: https://lkml.kernel.org/r/1517522386-18410-4-git-send-email-karahmed@amazon.de Signed-off-by: David Woodhouse Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/cpuid.c | 8 +++++++- arch/x86/kvm/cpuid.h | 8 ++++++++ arch/x86/kvm/vmx.c | 15 +++++++++++++++ arch/x86/kvm/x86.c | 1 + 4 files changed, 31 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 42323be..4d3555b 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -380,6 +380,10 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, /* cpuid 7.0.ecx*/ const u32 kvm_cpuid_7_0_ecx_x86_features = F(PKU) | 0 /*OSPKE*/; + /* cpuid 7.0.edx*/ + const u32 kvm_cpuid_7_0_edx_x86_features = + F(ARCH_CAPABILITIES); + /* all calls to cpuid_count() should be made on the same cpu */ get_cpu(); @@ -462,12 +466,14 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, /* PKU is not yet implemented for shadow paging. */ if (!tdp_enabled) entry->ecx &= ~F(PKU); + entry->edx &= kvm_cpuid_7_0_edx_x86_features; + cpuid_mask(&entry->edx, CPUID_7_EDX); } else { entry->ebx = 0; entry->ecx = 0; + entry->edx = 0; } entry->eax = 0; - entry->edx = 0; break; } case 9: diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h index f4a2a1a..a69906c 100644 --- a/arch/x86/kvm/cpuid.h +++ b/arch/x86/kvm/cpuid.h @@ -163,6 +163,14 @@ static inline bool guest_cpuid_has_ibpb(struct kvm_vcpu *vcpu) return best && (best->edx & bit(X86_FEATURE_SPEC_CTRL)); } +static inline bool guest_cpuid_has_arch_capabilities(struct kvm_vcpu *vcpu) +{ + struct kvm_cpuid_entry2 *best; + + best = kvm_find_cpuid_entry(vcpu, 7, 0); + return best && (best->edx & bit(X86_FEATURE_ARCH_CAPABILITIES)); +} + /* * NRIPS is provided through cpuidfn 0x8000000a.edx bit 3 diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 855df75..d8e3c02 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -551,6 +551,8 @@ struct vcpu_vmx { u64 msr_guest_kernel_gs_base; #endif + u64 arch_capabilities; + u32 vm_entry_controls_shadow; u32 vm_exit_controls_shadow; /* @@ -2976,6 +2978,12 @@ 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_arch_capabilities(vcpu)) + 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; @@ -3102,6 +3110,11 @@ 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)) @@ -5173,6 +5186,8 @@ static int 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 abbb37a..d01742e 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -975,6 +975,7 @@ 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