Commit f4bbd9aa authored by Avi Kivity's avatar Avi Kivity
Browse files

KVM: Load real mode segments correctly 



Real mode segments to not reference the GDT or LDT; they simply compute
base = selector * 16.

Signed-off-by: default avatarAvi Kivity <avi@qumranet.com>
parent a16b20da

arch/x86/kvm/x86.c

+22 −0
Original line number Diff line number Diff line
@@ -3588,11 +3588,33 @@ static int load_segment_descriptor_to_kvm_desct(struct kvm_vcpu *vcpu, 
	return 0;

}



int kvm_load_realmode_segment(struct kvm_vcpu *vcpu, u16 selector, int seg)

{

	struct kvm_segment segvar = {

		.base = selector << 4,

		.limit = 0xffff,

		.selector = selector,

		.type = 3,

		.present = 1,

		.dpl = 3,

		.db = 0,

		.s = 1,

		.l = 0,

		.g = 0,

		.avl = 0,

		.unusable = 0,

	};

	kvm_x86_ops->set_segment(vcpu, &segvar, seg);

	return 0;

}



int kvm_load_segment_descriptor(struct kvm_vcpu *vcpu, u16 selector,

				int type_bits, int seg)

{

	struct kvm_segment kvm_seg;



	if (!(vcpu->arch.cr0 & X86_CR0_PE))

		return kvm_load_realmode_segment(vcpu, selector, seg);

	if (load_segment_descriptor_to_kvm_desct(vcpu, selector, &kvm_seg))

		return 1;

	kvm_seg.type |= type_bits;