From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH v2 28/30] KVM: x86 emulator: restart string instruction without going back to a guest. Date: Sun, 14 Mar 2010 18:56:37 +0200 Message-ID: <4B9D1545.2020902@redhat.com> References: <1268583675-3101-1-git-send-email-gleb@redhat.com> <1268583675-3101-29-git-send-email-gleb@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: mtosatti@redhat.com, kvm@vger.kernel.org To: Gleb Natapov Return-path: Received: from mx1.redhat.com ([209.132.183.28]:31228 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932709Ab0CNQ4j (ORCPT ); Sun, 14 Mar 2010 12:56:39 -0400 Received: from int-mx05.intmail.prod.int.phx2.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.18]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id o2EGud1G020340 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Sun, 14 Mar 2010 12:56:39 -0400 Received: from cleopatra.tlv.redhat.com (cleopatra.tlv.redhat.com [10.35.255.11]) by int-mx05.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id o2EGuc3K028756 for ; Sun, 14 Mar 2010 12:56:38 -0400 In-Reply-To: <1268583675-3101-29-git-send-email-gleb@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On 03/14/2010 06:21 PM, Gleb Natapov wrote: > Currently when string instruction is only partially complete we go back > to a guest mode, guest tries to reexecute instruction and exits again > and at this point emulation continues. Avoid all of this by restarting > instruction without going back to a guest mode, but return to a guest > mode on each page boundary to allow interrupt injection. Pending > exception causes immediate guest entry too. > > @@ -2913,6 +2917,8 @@ writeback: > c->dst.ptr = (unsigned long *) > register_address(c, es_base(ctxt), > c->regs[VCPU_REGS_RDI]); > + if (!(c->regs[VCPU_REGS_RDI]& ~PAGE_MASK)) > + ctxt->restart = false; > } > What if rdi is odd and operand size != 1? Suggest simply reentering every N executions. -- error compiling committee.c: too many arguments to function