releases/2.6.36.2/kvm-correct-ordering-of-ldt-reload-wrt-fs-gs-reload.patch

   1 From 0a77fe4c188e25917799f2356d4aa5e6d80c39a2 Mon Sep 17 00:00:00 2001
   2 From: Avi Kivity <avi@redhat.com>
   3 Date: Tue, 19 Oct 2010 18:48:35 +0200
   4 Subject: KVM: Correct ordering of ldt reload wrt fs/gs reload
   5
   6 From: Avi Kivity <avi@redhat.com>
   7
   8 commit 0a77fe4c188e25917799f2356d4aa5e6d80c39a2 upstream.
   9
  10 If fs or gs refer to the ldt, they must be reloaded after the ldt.  Reorder
  11 the code to that effect.
  12
  13 Userspace code that uses the ldt with kvm is nonexistent, so this doesn't fix
  14 a user-visible bug.
  15
  16 Signed-off-by: Avi Kivity <avi@redhat.com>
  17 Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
  18 Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
  19
  20 ---
  21  arch/x86/kvm/svm.c |    2 +-
  22  arch/x86/kvm/vmx.c |    4 ++--
  23  2 files changed, 3 insertions(+), 3 deletions(-)
  24
  25 --- a/arch/x86/kvm/svm.c
  26 +++ b/arch/x86/kvm/svm.c
  27 @@ -3281,6 +3281,7 @@ static void svm_vcpu_run(struct kvm_vcpu
  28         vcpu->arch.regs[VCPU_REGS_RIP] = svm->vmcb->save.rip;
  29
  30         load_host_msrs(vcpu);
  31 +       kvm_load_ldt(ldt_selector);
  32         loadsegment(fs, fs_selector);
  33  #ifdef CONFIG_X86_64
  34         load_gs_index(gs_selector);
  35 @@ -3288,7 +3289,6 @@ static void svm_vcpu_run(struct kvm_vcpu
  36  #else
  37         loadsegment(gs, gs_selector);
  38  #endif
  39 -       kvm_load_ldt(ldt_selector);
  40
  41         reload_tss(vcpu);
  42
  43 --- a/arch/x86/kvm/vmx.c
  44 +++ b/arch/x86/kvm/vmx.c
  45 @@ -846,8 +846,6 @@ static void __vmx_load_host_state(struct
  46
  47         ++vmx->vcpu.stat.host_state_reload;
  48         vmx->host_state.loaded = 0;
  49 -       if (vmx->host_state.fs_reload_needed)
  50 -               loadsegment(fs, vmx->host_state.fs_sel);
  51         if (vmx->host_state.gs_ldt_reload_needed) {
  52                 kvm_load_ldt(vmx->host_state.ldt_sel);
  53  #ifdef CONFIG_X86_64
  54 @@ -857,6 +855,8 @@ static void __vmx_load_host_state(struct
  55                 loadsegment(gs, vmx->host_state.gs_sel);
  56  #endif
  57         }
  58 +       if (vmx->host_state.fs_reload_needed)
  59 +               loadsegment(fs, vmx->host_state.fs_sel);
  60         reload_tss();
  61  #ifdef CONFIG_X86_64
  62         if (is_long_mode(&vmx->vcpu)) {