KVM: emulator: Fix io permission checking for 64bit guest

Current implementation truncates upper 32bit of TR base address during IO
permission bitmap check. The patch fixes this.

Reported-and-tested-by: Francis Moreau <francis.moro@gmail.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 11 insertions, 4 deletions

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index b9c2b8e6c70c..01f08a65d09b 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4162,8 +4162,8 @@ static unsigned long emulator_get_cached_segment_base(int seg,
         return get_segment_base(vcpu, seg);
 }
 
-static bool emulator_get_cached_descriptor(struct desc_struct *desc, int seg,
-                                           struct kvm_vcpu *vcpu)
+static bool emulator_get_cached_descriptor(struct desc_struct *desc, u32 *base3,
+                                           int seg, struct kvm_vcpu *vcpu)
 {
         struct kvm_segment var;
 
@@ -4176,6 +4176,10 @@ static bool emulator_get_cached_descriptor(struct desc_struct *desc, int seg,
                 var.limit >>= 12;
         set_desc_limit(desc, var.limit);
         set_desc_base(desc, (unsigned long)var.base);
+#ifdef CONFIG_X86_64
+        if (base3)
+                *base3 = var.base >> 32;
+#endif
         desc->type = var.type;
         desc->s = var.s;
         desc->dpl = var.dpl;
@@ -4188,8 +4192,8 @@ static bool emulator_get_cached_descriptor(struct desc_struct *desc, int seg,
         return true;
 }
 
-static void emulator_set_cached_descriptor(struct desc_struct *desc, int seg,
-                                           struct kvm_vcpu *vcpu)
+static void emulator_set_cached_descriptor(struct desc_struct *desc, u32 base3,
+                                           int seg, struct kvm_vcpu *vcpu)
 {
         struct kvm_segment var;
 
@@ -4197,6 +4201,9 @@ static void emulator_set_cached_descriptor(struct desc_struct *desc, int seg,
         kvm_get_segment(vcpu, &var, seg);
 
         var.base = get_desc_base(desc);
+#ifdef CONFIG_X86_64
+        var.base |= ((u64)base3) << 32;
+#endif
         var.limit = get_desc_limit(desc);
         if (desc->g)
                 var.limit = (var.limit << 12) | 0xfff;