Commit a035d5c6 authored by Paolo Bonzini's avatar Paolo Bonzini Committed by Gleb Natapov
Browse files

KVM: emulator: emulate AAM 



This is used by SGABIOS, KVM breaks with emulate_invalid_guest_state=1.

AAM needs the source operand to be unsigned; do the same in AAD as well
for consistency, even though it does not affect the result.

Reported-by: default avatarJun'ichi Nomura <j-nomura@ce.jp.nec.com>
Cc: stable@vger.kernel.org # 3.9
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarGleb Natapov <gleb@redhat.com>
parent 8d76c49e

arch/x86/kvm/emulate.c

+24 −1
Original line number Diff line number Diff line
@@ -2996,6 +2996,28 @@ static int em_das(struct x86_emulate_ctxt *ctxt) 
	return X86EMUL_CONTINUE;

}



static int em_aam(struct x86_emulate_ctxt *ctxt)

{

	u8 al, ah;



	if (ctxt->src.val == 0)

		return emulate_de(ctxt);



	al = ctxt->dst.val & 0xff;

	ah = al / ctxt->src.val;

	al %= ctxt->src.val;



	ctxt->dst.val = (ctxt->dst.val & 0xffff0000) | al | (ah << 8);



	/* Set PF, ZF, SF */

	ctxt->src.type = OP_IMM;

	ctxt->src.val = 0;

	ctxt->src.bytes = 1;

	fastop(ctxt, em_or);



	return X86EMUL_CONTINUE;

}



static int em_aad(struct x86_emulate_ctxt *ctxt)

{

	u8 al = ctxt->dst.val & 0xff;
@@ -3936,7 +3958,8 @@ static const struct opcode opcode_table[256] = { 
	/* 0xD0 - 0xD7 */

	G(Src2One | ByteOp, group2), G(Src2One, group2),

	G(Src2CL | ByteOp, group2), G(Src2CL, group2),

	N, I(DstAcc | SrcImmByte | No64, em_aad), N, N,

	I(DstAcc | SrcImmUByte | No64, em_aam),

	I(DstAcc | SrcImmUByte | No64, em_aad), N, N,

	/* 0xD8 - 0xDF */

	N, E(0, &escape_d9), N, E(0, &escape_db), N, E(0, &escape_dd), N, N,

	/* 0xE0 - 0xE7 */

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