diff options
| author | Avi Kivity <avi@redhat.com> | 2010-10-28 16:48:12 -0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-11-22 10:47:33 -0800 |
| commit | ffc109c28a6a4cb5047df82b1d18ad7a13d3e247 (patch) | |
| tree | ac75613711d4bf998430a810fc379b6bdc5d8257 /arch | |
| parent | dbd877e34acf443e11c09361d0eaeaade441de86 (diff) | |
KVM: VMX: Fix host GDT.LIMIT corruption
commit 3444d7da1839b851eefedd372978d8a982316c36 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kvm/vmx.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 6a28d5d95e8f..1850cb054d12 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -130,6 +130,7 @@ static u64 construct_eptp(unsigned long root_hpa); 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; @@ -690,6 +691,7 @@ static void __vmx_load_host_state(struct vcpu_vmx *vmx) save_msrs(vmx->guest_msrs, vmx->save_nmsrs); load_msrs(vmx->host_msrs, vmx->save_nmsrs); reload_host_efer(vmx); + load_gdt(&__get_cpu_var(host_gdt)); } static void vmx_load_host_state(struct vcpu_vmx *vmx) @@ -1176,6 +1178,8 @@ static void hardware_enable(void *garbage) asm volatile (ASM_VMX_VMXON_RAX : : "a"(&phys_addr), "m"(phys_addr) : "memory", "cc"); + + store_gdt(&__get_cpu_var(host_gdt)); } static void vmclear_local_vcpus(void) |