3.16.72-rc1 review patch. If anyone has any objections, please let me know.
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From: Sean Christopherson sean.j.christopherson@intel.com
commit 0cf9135b773bf32fba9dd8e6699c1b331ee4b749 upstream.
The CPUID flag ARCH_CAPABILITIES is unconditioinally exposed to host userspace for all x86 hosts, i.e. KVM advertises ARCH_CAPABILITIES regardless of hardware support under the pretense that KVM fully emulates MSR_IA32_ARCH_CAPABILITIES. Unfortunately, only VMX hosts handle accesses to MSR_IA32_ARCH_CAPABILITIES (despite KVM_GET_MSRS also reporting MSR_IA32_ARCH_CAPABILITIES for all hosts).
Move the MSR_IA32_ARCH_CAPABILITIES handling to common x86 code so that it's emulated on AMD hosts.
Fixes: 1eaafe91a0df4 ("kvm: x86: IA32_ARCH_CAPABILITIES is always supported") Reported-by: Xiaoyao Li xiaoyao.li@linux.intel.com Cc: Jim Mattson jmattson@google.com Signed-off-by: Sean Christopherson sean.j.christopherson@intel.com Signed-off-by: Paolo Bonzini pbonzini@redhat.com [bwh: Backported to 3.16: - Keep using guest_cpuid_has_arch_capabilities() to check the CPUID - Keep using rdmsrl() to get the initial value of IA32_ARCH_CAPABILITIES - Adjust filenames, context] Signed-off-by: Ben Hutchings ben@decadent.org.uk --- arch/x86/include/asm/kvm_host.h | 1 + arch/x86/kvm/vmx.c | 13 ------------- arch/x86/kvm/x86.c | 12 ++++++++++++ 4 files changed, 13 insertions(+), 14 deletions(-)
--- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -363,6 +363,7 @@ struct kvm_vcpu_arch { int mp_state; u64 ia32_misc_enable_msr; bool tpr_access_reporting; + u64 arch_capabilities;
/* * Paging state of the vcpu --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -433,7 +433,6 @@ struct vcpu_vmx { u64 msr_guest_kernel_gs_base; #endif
- u64 arch_capabilities; u64 spec_ctrl;
u32 vm_entry_controls_shadow; @@ -2481,12 +2480,6 @@ static int vmx_get_msr(struct kvm_vcpu *
msr_info->data = to_vmx(vcpu)->spec_ctrl; 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; @@ -2636,11 +2629,6 @@ 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)) @@ -4583,9 +4571,6 @@ 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);
/* 22.2.1, 20.8.1 */ --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2089,6 +2089,11 @@ int kvm_set_msr_common(struct kvm_vcpu * case MSR_F15H_EX_CFG: break;
+ case MSR_IA32_ARCH_CAPABILITIES: + if (!msr_info->host_initiated) + return 1; + vcpu->arch.arch_capabilities = data; + break; case MSR_EFER: return set_efer(vcpu, data); case MSR_K7_HWCR: @@ -2479,6 +2484,12 @@ int kvm_get_msr_common(struct kvm_vcpu * case MSR_IA32_UCODE_REV: msr_info->data = 0x100000000ULL; break; + case MSR_IA32_ARCH_CAPABILITIES: + if (!msr_info->host_initiated && + !guest_cpuid_has_arch_capabilities(vcpu)) + return 1; + msr_info->data = vcpu->arch.arch_capabilities; + break; case MSR_MTRRcap: msr_info->data = 0x500 | KVM_NR_VAR_MTRR; break; @@ -6957,6 +6968,9 @@ int kvm_arch_vcpu_setup(struct kvm_vcpu { int r;
+ if (boot_cpu_has(X86_FEATURE_ARCH_CAPABILITIES)) + rdmsrl(MSR_IA32_ARCH_CAPABILITIES, + vcpu->arch.arch_capabilities); vcpu->arch.mtrr_state.have_fixed = 1; r = vcpu_load(vcpu); if (r)