From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: Fix kernel pio emulation mistake Date: Sun, 22 Mar 2009 11:09:55 +0200 Message-ID: <49C60063.10205@redhat.com> References: <9832F13BD22FB94A829F798DA4A828050196AF5598@pdsmsx503.ccr.corp.intel.com> <49C211F1.50508@redhat.com> <9832F13BD22FB94A829F798DA4A8280501A1D68ACD@pdsmsx503.ccr.corp.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: "kvm@vger.kernel.org" To: "Dong, Eddie" Return-path: Received: from mx2.redhat.com ([66.187.237.31]:41660 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752831AbZCVJJ7 (ORCPT ); Sun, 22 Mar 2009 05:09:59 -0400 In-Reply-To: <9832F13BD22FB94A829F798DA4A8280501A1D68ACD@pdsmsx503.ccr.corp.intel.com> Sender: kvm-owner@vger.kernel.org List-ID: Dong, Eddie wrote: >> kvm_emulate_pio() returns 1 when emulation is complete, >> and 0 when emulation needs further processing in >> userspace. So I think in both cases cannot_emulate is >> the wrong answer. I think 'in' emulation gets it right. >> > > OK, yes. Do u mean this? I may misunderstand. > > Thx, eddie > > diff --git a/arch/x86/kvm/x86_emulate.c b/arch/x86/kvm/x86_emulate.c > index ca91749..838fdc9 100644 > --- a/arch/x86/kvm/x86_emulate.c > +++ b/arch/x86/kvm/x86_emulate.c > @@ -1838,11 +1838,11 @@ special_insn: > io_dir_in = 0; > do_io: if (kvm_emulate_pio(ctxt->vcpu, NULL, io_dir_in, > (c->d & ByteOp) ? 1 : c->op_bytes, > - port) != 0) { > + port) == 0) { > c->eip = saved_eip; > - goto cannot_emulate; > + return -1; > } > - break; > + return 0; > case 0xf4: /* hlt */ > ctxt->vcpu->arch.halt_request = 1; > break; I think this is right, but can you add a testcase to user/test/x86/realmode.c? (you need to set the emulate_invalid_guest_state module parameter to 1 to run this test) -- error compiling committee.c: too many arguments to function