Commit cb84b55f authored by Marcelo Tosatti's avatar Marcelo Tosatti

KVM: x86: raise TSS exception for NULL CS and SS segments

Windows 2003 uses task switch to triple fault and reboot (the other
exception being reserved pdptrs bits).
Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
parent 3fd28fce
...@@ -4410,6 +4410,15 @@ static int is_vm86_segment(struct kvm_vcpu *vcpu, int seg) ...@@ -4410,6 +4410,15 @@ static int is_vm86_segment(struct kvm_vcpu *vcpu, int seg)
(kvm_get_rflags(vcpu) & X86_EFLAGS_VM); (kvm_get_rflags(vcpu) & X86_EFLAGS_VM);
} }
static void kvm_check_segment_descriptor(struct kvm_vcpu *vcpu, int seg,
u16 selector)
{
/* NULL selector is not valid for CS and SS */
if (seg == VCPU_SREG_CS || seg == VCPU_SREG_SS)
if (!selector)
kvm_queue_exception_e(vcpu, TS_VECTOR, selector >> 3);
}
int kvm_load_segment_descriptor(struct kvm_vcpu *vcpu, u16 selector, int kvm_load_segment_descriptor(struct kvm_vcpu *vcpu, u16 selector,
int type_bits, int seg) int type_bits, int seg)
{ {
...@@ -4419,6 +4428,8 @@ int kvm_load_segment_descriptor(struct kvm_vcpu *vcpu, u16 selector, ...@@ -4419,6 +4428,8 @@ int kvm_load_segment_descriptor(struct kvm_vcpu *vcpu, u16 selector,
return kvm_load_realmode_segment(vcpu, selector, seg); return kvm_load_realmode_segment(vcpu, selector, seg);
if (load_segment_descriptor_to_kvm_desct(vcpu, selector, &kvm_seg)) if (load_segment_descriptor_to_kvm_desct(vcpu, selector, &kvm_seg))
return 1; return 1;
kvm_check_segment_descriptor(vcpu, seg, selector);
kvm_seg.type |= type_bits; kvm_seg.type |= type_bits;
if (seg != VCPU_SREG_SS && seg != VCPU_SREG_CS && if (seg != VCPU_SREG_SS && seg != VCPU_SREG_CS &&
......
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