patches/kernel/0283-x86-kvm-Set-IBPB-when-switching-VM.patch

   1 From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
   2 From: Tim Chen <tim.c.chen@linux.intel.com>
   3 Date: Fri, 13 Oct 2017 14:31:46 -0700
   4 Subject: [PATCH] x86/kvm: Set IBPB when switching VM
   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 Set IBPB (Indirect branch prediction barrier) when switching VM.
  13
  14 Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
  15 Signed-off-by: Andy Whitcroft <apw@canonical.com>
  16 Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
  17 (cherry picked from commit 665076ad780e8620505c742cfcb4b0f3fb99324a)
  18 Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
  19 ---
  20  arch/x86/kvm/vmx.c | 3 +++
  21  1 file changed, 3 insertions(+)
  22
  23 diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
  24 index daff9962c90a..8df195bbb41d 100644
  25 --- a/arch/x86/kvm/vmx.c
  26 +++ b/arch/x86/kvm/vmx.c
  27 @@ -1488,6 +1488,7 @@ static void vmcs_load(struct vmcs *vmcs)
  28         if (error)
  29                 printk(KERN_ERR "kvm: vmptrld %p/%llx failed\n",
  30                        vmcs, phys_addr);
  31 +
  32  }
  33
  34  #ifdef CONFIG_KEXEC_CORE
  35 @@ -2268,6 +2269,8 @@ static void vmx_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
  36         if (per_cpu(current_vmcs, cpu) != vmx->loaded_vmcs->vmcs) {
  37                 per_cpu(current_vmcs, cpu) = vmx->loaded_vmcs->vmcs;
  38                 vmcs_load(vmx->loaded_vmcs->vmcs);
  39 +               if (boot_cpu_has(X86_FEATURE_SPEC_CTRL))
  40 +                       native_wrmsrl(MSR_IA32_PRED_CMD, FEATURE_SET_IBPB);
  41         }
  42
  43         if (!already_loaded) {
  44 --
  45 2.14.2
  46