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| author | Avi Kivity <avi@redhat.com> | 2010-07-26 18:32:38 +0300 |
|---|---|---|
| committer | Paul Gortmaker <paul.gortmaker@windriver.com> | 2011-01-06 18:08:21 -0500 |
| commit | 01d1063c93a96ddae04498682eeb50cfd1760a21 (patch) | |
| tree | ad9f0a273befab87d7cad40f27461cf1b8079fd1 | |
| parent | 85a66b34c00d0a3acadedd1c4107fbc8587e4f69 (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: Paul Gortmaker <paul.gortmaker@windriver.com>
| -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 3c86c42aa6c..11db9116eca 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -170,6 +170,7 @@ 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; @@ -717,6 +718,7 @@ static void __vmx_load_host_state(struct vcpu_vmx *vmx) wrmsrl(MSR_KERNEL_GS_BASE, vmx->msr_host_kernel_gs_base); } #endif + load_gdt(&__get_cpu_var(host_gdt)); } static void vmx_load_host_state(struct vcpu_vmx *vmx) @@ -1218,6 +1220,8 @@ static int hardware_enable(void *garbage) ept_sync_global(); + store_gdt(&__get_cpu_var(host_gdt)); + return 0; } |