aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorAvi Kivity <avi@redhat.com>2010-07-26 18:32:38 +0300
committerAvi Kivity <avi@redhat.com>2010-08-02 08:10:18 +0300
commit3444d7da1839b851eefedd372978d8a982316c36 (patch)
treeb9fef27fbe36b455dc242670fa0f4025a2df1dc2
parent9a3aad70572c3f4d55e7f09ac4eb313d41d0a484 (diff)
downloadmrst-s0i3-test-3444d7da1839b851eefedd372978d8a982316c36.tar.gz
mrst-s0i3-test-3444d7da1839b851eefedd372978d8a982316c36.tar.xz
mrst-s0i3-test-3444d7da1839b851eefedd372978d8a982316c36.zip
KVM: VMX: Fix host GDT.LIMIT corruption
vmx does not restore GDT.LIMIT to the host value, instead it sets it to 64KB. This means host userspace can learn a few bits of host memory. Fix by reloading GDTR when we load other host state. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
-rw-r--r--arch/x86/kvm/vmx.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 2fdcc9819f3..27a0222c294 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -185,6 +185,7 @@ static void kvm_cpu_vmxoff(void);
static DEFINE_PER_CPU(struct vmcs *, vmxarea);
static DEFINE_PER_CPU(struct vmcs *, current_vmcs);
static DEFINE_PER_CPU(struct list_head, vcpus_on_cpu);
+static DEFINE_PER_CPU(struct desc_ptr, host_gdt);
static unsigned long *vmx_io_bitmap_a;
static unsigned long *vmx_io_bitmap_b;
@@ -871,6 +872,7 @@ static void __vmx_load_host_state(struct vcpu_vmx *vmx)
#endif
if (current_thread_info()->status & TS_USEDFPU)
clts();
+ load_gdt(&__get_cpu_var(host_gdt));
}
static void vmx_load_host_state(struct vcpu_vmx *vmx)
@@ -1379,6 +1381,8 @@ static int hardware_enable(void *garbage)
ept_sync_global();
}
+ store_gdt(&__get_cpu_var(host_gdt));
+
return 0;
}