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authorAvi Kivity <avi@redhat.com>2010-10-28 16:48:12 -0200
committerGreg Kroah-Hartman <gregkh@suse.de>2010-11-22 10:47:33 -0800
commitffc109c28a6a4cb5047df82b1d18ad7a13d3e247 (patch)
treeac75613711d4bf998430a810fc379b6bdc5d8257 /arch
parentdbd877e34acf443e11c09361d0eaeaade441de86 (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.c4
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)