From mboxrd@z Thu Jan 1 00:00:00 1970 From: Takuya Yoshikawa Subject: Re: [PATCH 1/5] KVM: x86 emulator: Use single stage decoding for Group 1 instructions Date: Wed, 23 Mar 2011 00:35:40 +0900 Message-ID: <20110323003540.53a281bb.takuya.yoshikawa@gmail.com> References: <20110314001524.f35e8a3f.takuya.yoshikawa@gmail.com> <20110314001727.89e302d7.takuya.yoshikawa@gmail.com> <20110314151140.GT10151@redhat.com> <20110315063232.6156395a.takuya.yoshikawa@gmail.com> <20110315093507.GU10151@redhat.com> <20110315230651.4ba2029c.takuya.yoshikawa@gmail.com> <4D889BC1.2010907@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: Gleb Natapov , mtosatti@redhat.com, kvm@vger.kernel.org, yoshikawa.takuya@oss.ntt.co.jp To: Avi Kivity Return-path: Received: from mail-wy0-f174.google.com ([74.125.82.174]:52717 "EHLO mail-wy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753816Ab1CVPf5 (ORCPT ); Tue, 22 Mar 2011 11:35:57 -0400 Received: by wya21 with SMTP id 21so6814175wya.19 for ; Tue, 22 Mar 2011 08:35:56 -0700 (PDT) In-Reply-To: <4D889BC1.2010907@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On Tue, 22 Mar 2011 14:53:21 +0200 Avi Kivity wrote: > > I prefer to have the patchset fully updated, even if it takes a while. > Good luck with the recovery! Things already got back as usual, thanks. I had expected much longer time. BTW, is it better to wait until rc1 is released when we send patches for the next merge window? > > > > What is the difference of CMPS and SCAS? > > > > > > > > > > > One compares to memory locations and another memory with AX register. > > > > I wanted to know whether we should introduce em_cmps() or em_scas() later. > > > > Probably we can eliminate introducing em_scas() because it should be > > completely same as em_cmp(). > > I agree. > > > But em_cmps() will be needed for inserting > > c->dst.type = OP_NONE; > > before em_cmp(). > > I think we can put this line into em_cmp(). In fact, it looks like CMP > r/m, reg will now write back the data into memory, which is wrong. So I > recommend a first patch to add c->dst.type = OP_NONE before the cmp: > label, so we have a fix patch followed by a refactoring patch. I'll update like that! > > Later we can have a ReadOnly opcode table bit, so we can disable > writeback from the opcode tables, not the code. OK, then we can remove the line at this timing. Takuya