Commit dd307d01 authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

KVM: x86: emulate sldt and str 



These are needed to handle the descriptor table vmexits when emulating
UMIP.

Reviewed-by: default avatarWanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent ae3e61e1

arch/x86/kvm/emulate.c

+26 −6
Original line number Diff line number Diff line
@@ -3633,17 +3633,27 @@ static int em_rdmsr(struct x86_emulate_ctxt *ctxt) 
	return X86EMUL_CONTINUE;

}



static int em_mov_rm_sreg(struct x86_emulate_ctxt *ctxt)

static int em_store_sreg(struct x86_emulate_ctxt *ctxt, int segment)

{

	if (ctxt->modrm_reg > VCPU_SREG_GS)

		return emulate_ud(ctxt);

	if (segment > VCPU_SREG_GS &&

	    (ctxt->ops->get_cr(ctxt, 4) & X86_CR4_UMIP) &&

	    ctxt->ops->cpl(ctxt) > 0)

		return emulate_gp(ctxt, 0);



	ctxt->dst.val = get_segment_selector(ctxt, ctxt->modrm_reg);

	ctxt->dst.val = get_segment_selector(ctxt, segment);

	if (ctxt->dst.bytes == 4 && ctxt->dst.type == OP_MEM)

		ctxt->dst.bytes = 2;

	return X86EMUL_CONTINUE;

}



static int em_mov_rm_sreg(struct x86_emulate_ctxt *ctxt)

{

	if (ctxt->modrm_reg > VCPU_SREG_GS)

		return emulate_ud(ctxt);



	return em_store_sreg(ctxt, ctxt->modrm_reg);

}



static int em_mov_sreg_rm(struct x86_emulate_ctxt *ctxt)

{

	u16 sel = ctxt->src.val;
@@ -3659,6 +3669,11 @@ static int em_mov_sreg_rm(struct x86_emulate_ctxt *ctxt) 
	return load_segment_descriptor(ctxt, sel, ctxt->modrm_reg);

}



static int em_sldt(struct x86_emulate_ctxt *ctxt)

{

	return em_store_sreg(ctxt, VCPU_SREG_LDTR);

}



static int em_lldt(struct x86_emulate_ctxt *ctxt)

{

	u16 sel = ctxt->src.val;
@@ -3668,6 +3683,11 @@ static int em_lldt(struct x86_emulate_ctxt *ctxt) 
	return load_segment_descriptor(ctxt, sel, VCPU_SREG_LDTR);

}



static int em_str(struct x86_emulate_ctxt *ctxt)

{

	return em_store_sreg(ctxt, VCPU_SREG_TR);

}



static int em_ltr(struct x86_emulate_ctxt *ctxt)

{

	u16 sel = ctxt->src.val;
@@ -4372,8 +4392,8 @@ static const struct opcode group5[] = { 
};



static const struct opcode group6[] = {

	DI(Prot | DstMem,	sldt),

	DI(Prot | DstMem,	str),

	II(Prot | DstMem,	   em_sldt, sldt),

	II(Prot | DstMem,	   em_str, str),

	II(Prot | Priv | SrcMem16, em_lldt, lldt),

	II(Prot | Priv | SrcMem16, em_ltr, ltr),

	N, N, N, N,