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authorAvi Kivity <avi@redhat.com>2010-07-26 18:32:38 +0300
committerPaul Gortmaker <paul.gortmaker@windriver.com>2011-01-06 18:08:21 -0500
commit01d1063c93a96ddae04498682eeb50cfd1760a21 (patch)
treead9f0a273befab87d7cad40f27461cf1b8079fd1 /arch
parent85a66b34c00d0a3acadedd1c4107fbc8587e4f69 (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>
Diffstat (limited to 'arch')
-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 3c86c42aa6c4..11db9116eca0 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;
}