[150/289] KVM: Correct ordering of ldt reload wrt fs/gs reload

Greg KH
2010-12-08T01:32:33Z

From: Avi Kivity <avi@redhat.com>

commit 0a77fe4c188e25917799f2356d4aa5e6d80c39a2 upstream.

If fs or gs refer to the ldt, they must be reloaded after the ldt. Reorder
the code to that effect.

Userspace code that uses the ldt with kvm is nonexistent, so this doesn't fix
a user-visible bug.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
arch/x86/kvm/svm.c | 2 +-
arch/x86/kvm/vmx.c | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)

--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -3281,6 +3281,7 @@ static void svm_vcpu_run(struct kvm_vcpu
vcpu->arch.regs[VCPU_REGS_RIP] = svm->vmcb->save.rip;

load_host_msrs(vcpu);
+ kvm_load_ldt(ldt_selector);
loadsegment(fs, fs_selector);
#ifdef CONFIG_X86_64
load_gs_index(gs_selector);
@@ -3288,7 +3289,6 @@ static void svm_vcpu_run(struct kvm_vcpu
#else
loadsegment(gs, gs_selector);
#endif
- kvm_load_ldt(ldt_selector);

reload_tss(vcpu);

--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -846,8 +846,6 @@ static void __vmx_load_host_state(struct

++vmx->vcpu.stat.host_state_reload;
vmx->host_state.loaded = 0;
- if (vmx->host_state.fs_reload_needed)
- loadsegment(fs, vmx->host_state.fs_sel);
if (vmx->host_state.gs_ldt_reload_needed) {
kvm_load_ldt(vmx->host_state.ldt_sel);
#ifdef CONFIG_X86_64
@@ -857,6 +855,8 @@ static void __vmx_load_host_state(struct
loadsegment(gs, vmx->host_state.gs_sel);
#endif
}
+ if (vmx->host_state.fs_reload_needed)
+ loadsegment(fs, vmx->host_state.fs_sel);
reload_tss();
#ifdef CONFIG_X86_64
if (is_long_mode(&vmx->vcpu)) {