patches/kernel/0011-KVM-x86-Emulate-MSR_IA32_ARCH_CAPABILITIES-on-AMD-ho.patch

   1 From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
   2 From: Sean Christopherson <sean.j.christopherson@intel.com>
   3 Date: Thu, 7 Mar 2019 15:43:02 -0800
   4 Subject: [PATCH] KVM: x86: Emulate MSR_IA32_ARCH_CAPABILITIES on AMD hosts
   5
   6 BugLink: https://bugs.launchpad.net/bugs/1823060
   7
   8 commit 0cf9135b773bf32fba9dd8e6699c1b331ee4b749 upstream.
   9
  10 The CPUID flag ARCH_CAPABILITIES is unconditioinally exposed to host
  11 userspace for all x86 hosts, i.e. KVM advertises ARCH_CAPABILITIES
  12 regardless of hardware support under the pretense that KVM fully
  13 emulates MSR_IA32_ARCH_CAPABILITIES.  Unfortunately, only VMX hosts
  14 handle accesses to MSR_IA32_ARCH_CAPABILITIES (despite KVM_GET_MSRS
  15 also reporting MSR_IA32_ARCH_CAPABILITIES for all hosts).
  16
  17 Move the MSR_IA32_ARCH_CAPABILITIES handling to common x86 code so
  18 that it's emulated on AMD hosts.
  19
  20 Fixes: 1eaafe91a0df4 ("kvm: x86: IA32_ARCH_CAPABILITIES is always supported")
  21 Cc: stable@vger.kernel.org
  22 Reported-by: Xiaoyao Li <xiaoyao.li@linux.intel.com>
  23 Cc: Jim Mattson <jmattson@google.com>
  24 Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
  25 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
  26 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  27
  28 Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
  29
  30 (back ported from commit 0cf9135b773bf32fba9dd8e6699c1b331ee4b749)
  31 Backported-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
  32 Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
  33 ---
  34  arch/x86/include/asm/kvm_host.h |  1 +
  35  arch/x86/kvm/vmx.c              | 14 --------------
  36  arch/x86/kvm/x86.c              | 12 ++++++++++++
  37  3 files changed, 13 insertions(+), 14 deletions(-)
  38
  39 diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
  40 index c2bb7da8e5b4..e238785c22d3 100644
  41 --- a/arch/x86/include/asm/kvm_host.h
  42 +++ b/arch/x86/include/asm/kvm_host.h
  43 @@ -509,6 +509,7 @@ struct kvm_vcpu_arch {
  44         bool tpr_access_reporting;
  45         u64 ia32_xss;
  46         u64 microcode_version;
  47 +       u64 arch_capabilities;
  48
  49         /*
  50          * Paging state of the vcpu
  51 diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
  52 index 921968c00dde..cddbdd2d615d 100644
  53 --- a/arch/x86/kvm/vmx.c
  54 +++ b/arch/x86/kvm/vmx.c
  55 @@ -750,7 +750,6 @@ struct vcpu_vmx {
  56         u64                   msr_guest_kernel_gs_base;
  57  #endif
  58
  59 -       u64                   arch_capabilities;
  60         u64                   spec_ctrl;
  61
  62         u32 vm_entry_controls_shadow;
  63 @@ -3485,12 +3484,6 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
  64
  65                 msr_info->data = to_vmx(vcpu)->spec_ctrl;
  66                 break;
  67 -       case MSR_IA32_ARCH_CAPABILITIES:
  68 -               if (!msr_info->host_initiated &&
  69 -                   !guest_cpuid_has(vcpu, X86_FEATURE_ARCH_CAPABILITIES))
  70 -                       return 1;
  71 -               msr_info->data = to_vmx(vcpu)->arch_capabilities;
  72 -               break;
  73         case MSR_IA32_SYSENTER_CS:
  74                 msr_info->data = vmcs_read32(GUEST_SYSENTER_CS);
  75                 break;
  76 @@ -3652,11 +3645,6 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
  77                 vmx_disable_intercept_for_msr(vmx->vmcs01.msr_bitmap, MSR_IA32_PRED_CMD,
  78                                               MSR_TYPE_W);
  79                 break;
  80 -       case MSR_IA32_ARCH_CAPABILITIES:
  81 -               if (!msr_info->host_initiated)
  82 -                       return 1;
  83 -               vmx->arch_capabilities = data;
  84 -               break;
  85         case MSR_IA32_CR_PAT:
  86                 if (vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_PAT) {
  87                         if (!kvm_mtrr_valid(vcpu, MSR_IA32_CR_PAT, data))
  88 @@ -5914,8 +5902,6 @@ static void vmx_vcpu_setup(struct vcpu_vmx *vmx)
  89                 ++vmx->nmsrs;
  90         }
  91
  92 -       vmx->arch_capabilities = kvm_get_arch_capabilities();
  93 -
  94         vm_exit_controls_init(vmx, vmcs_config.vmexit_ctrl);
  95
  96         /* 22.2.1, 20.8.1 */
  97 diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
  98 index be629513de13..88f910046a60 100644
  99 --- a/arch/x86/kvm/x86.c
 100 +++ b/arch/x86/kvm/x86.c
 101 @@ -2248,6 +2248,11 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 102                 if (msr_info->host_initiated)
 103                         vcpu->arch.microcode_version = data;
 104                 break;
 105 +       case MSR_IA32_ARCH_CAPABILITIES:
 106 +               if (!msr_info->host_initiated)
 107 +                       return 1;
 108 +               vcpu->arch.arch_capabilities = data;
 109 +               break;
 110         case MSR_EFER:
 111                 return set_efer(vcpu, data);
 112         case MSR_K7_HWCR:
 113 @@ -2544,6 +2549,12 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 114         case MSR_IA32_UCODE_REV:
 115                 msr_info->data = vcpu->arch.microcode_version;
 116                 break;
 117 +       case MSR_IA32_ARCH_CAPABILITIES:
 118 +               if (!msr_info->host_initiated &&
 119 +                   !guest_cpuid_has(vcpu, X86_FEATURE_ARCH_CAPABILITIES))
 120 +                       return 1;
 121 +               msr_info->data = vcpu->arch.arch_capabilities;
 122 +               break;
 123         case MSR_IA32_TSC:
 124                 msr_info->data = kvm_scale_tsc(vcpu, rdtsc()) + vcpu->arch.tsc_offset;
 125                 break;
 126 @@ -7957,6 +7968,7 @@ struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm,
 127
 128  int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
 129  {
 130 +       vcpu->arch.arch_capabilities = kvm_get_arch_capabilities();
 131         vcpu->arch.msr_platform_info = MSR_PLATFORM_INFO_CPUID_FAULT;
 132         kvm_vcpu_mtrr_init(vcpu);
 133         vcpu_load(vcpu);