patches/kernel/0296-KVM-x86-Add-speculative-control-CPUID-support-for-gu.patch

   1 From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
   2 From: Tom Lendacky <thomas.lendacky@amd.com>
   3 Date: Wed, 20 Dec 2017 10:55:47 +0000
   4 Subject: [PATCH] KVM: x86: Add speculative control CPUID support for guests
   5 MIME-Version: 1.0
   6 Content-Type: text/plain; charset=UTF-8
   7 Content-Transfer-Encoding: 8bit
   8
   9 CVE-2017-5753
  10 CVE-2017-5715
  11
  12 Provide the guest with the speculative control CPUID related values.
  13
  14 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
  15 Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
  16 Signed-off-by: Andy Whitcroft <apw@canonical.com>
  17 Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
  18 (cherry picked from commit db7641e5f41cd517c4181ce90c4f9ecc93af4b2b)
  19 Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
  20 ---
  21  arch/x86/kvm/cpuid.c | 12 ++++++++++--
  22  1 file changed, 10 insertions(+), 2 deletions(-)
  23
  24 diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
  25 index 19adbb418443..f64502d21a89 100644
  26 --- a/arch/x86/kvm/cpuid.c
  27 +++ b/arch/x86/kvm/cpuid.c
  28 @@ -70,6 +70,7 @@ u64 kvm_supported_xcr0(void)
  29  /* These are scattered features in cpufeatures.h. */
  30  #define KVM_CPUID_BIT_AVX512_4VNNIW     2
  31  #define KVM_CPUID_BIT_AVX512_4FMAPS     3
  32 +#define KVM_CPUID_BIT_SPEC_CTRL                26
  33  #define KF(x) bit(KVM_CPUID_BIT_##x)
  34
  35  int kvm_update_cpuid(struct kvm_vcpu *vcpu)
  36 @@ -387,7 +388,12 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
  37
  38         /* cpuid 7.0.edx*/
  39         const u32 kvm_cpuid_7_0_edx_x86_features =
  40 -               KF(AVX512_4VNNIW) | KF(AVX512_4FMAPS);
  41 +               KF(AVX512_4VNNIW) | KF(AVX512_4FMAPS) |
  42 +               KF(SPEC_CTRL);
  43 +
  44 +       /* cpuid 0x80000008.0.ebx */
  45 +       const u32 kvm_cpuid_80000008_0_ebx_x86_features =
  46 +               F(IBPB);
  47
  48         /* all calls to cpuid_count() should be made on the same cpu */
  49         get_cpu();
  50 @@ -622,7 +628,9 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
  51                 if (!g_phys_as)
  52                         g_phys_as = phys_as;
  53                 entry->eax = g_phys_as | (virt_as << 8);
  54 -               entry->ebx = entry->edx = 0;
  55 +               entry->ebx &= kvm_cpuid_80000008_0_ebx_x86_features;
  56 +               cpuid_mask(&entry->ebx, CPUID_8000_0008_EBX);
  57 +               entry->edx = 0;
  58                 break;
  59         }
  60         case 0x80000019:
  61 --
  62 2.14.2
  63