5.0-stable 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") Cc: stable@vger.kernel.org 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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/x86/include/asm/kvm_host.h | 1 + arch/x86/kvm/vmx/vmx.c | 13 ------------- arch/x86/kvm/vmx/vmx.h | 1 - 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 @@ -570,6 +570,7 @@ struct kvm_vcpu_arch { bool tpr_access_reporting; u64 ia32_xss; u64 microcode_version; + u64 arch_capabilities;
/* * Paging state of the vcpu --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -1679,12 +1679,6 @@ 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(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; @@ -1891,11 +1885,6 @@ 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)) @@ -4083,8 +4072,6 @@ static void vmx_vcpu_setup(struct vcpu_v ++vmx->nmsrs; }
- vmx->arch_capabilities = kvm_get_arch_capabilities(); - vm_exit_controls_init(vmx, vmx_vmexit_ctrl());
/* 22.2.1, 20.8.1 */ --- a/arch/x86/kvm/vmx/vmx.h +++ b/arch/x86/kvm/vmx/vmx.h @@ -191,7 +191,6 @@ struct vcpu_vmx { u64 msr_guest_kernel_gs_base; #endif
- u64 arch_capabilities; u64 spec_ctrl;
u32 vm_entry_controls_shadow; --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2443,6 +2443,11 @@ int kvm_set_msr_common(struct kvm_vcpu * if (msr_info->host_initiated) vcpu->arch.microcode_version = data; 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: @@ -2747,6 +2752,12 @@ int kvm_get_msr_common(struct kvm_vcpu * case MSR_IA32_UCODE_REV: msr_info->data = vcpu->arch.microcode_version; break; + case MSR_IA32_ARCH_CAPABILITIES: + if (!msr_info->host_initiated && + !guest_cpuid_has(vcpu, X86_FEATURE_ARCH_CAPABILITIES)) + return 1; + msr_info->data = vcpu->arch.arch_capabilities; + break; case MSR_IA32_TSC: msr_info->data = kvm_scale_tsc(vcpu, rdtsc()) + vcpu->arch.tsc_offset; break; @@ -8725,6 +8736,7 @@ struct kvm_vcpu *kvm_arch_vcpu_create(st
int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu) { + vcpu->arch.arch_capabilities = kvm_get_arch_capabilities(); vcpu->arch.msr_platform_info = MSR_PLATFORM_INFO_CPUID_FAULT; kvm_vcpu_mtrr_init(vcpu); vcpu_load(vcpu);