From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752831Ab1HCIKx (ORCPT ); Wed, 3 Aug 2011 04:10:53 -0400 Received: from mx1.redhat.com ([209.132.183.28]:11213 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752063Ab1HCIKs (ORCPT ); Wed, 3 Aug 2011 04:10:48 -0400 Message-ID: <4E390283.6050106@redhat.com> Date: Wed, 03 Aug 2011 11:10:43 +0300 From: Avi Kivity User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.18) Gecko/20110621 Fedora/3.1.11-1.fc15 Thunderbird/3.1.11 MIME-Version: 1.0 To: Xiao Guangrong CC: Marcelo Tosatti , LKML , KVM Subject: Re: [PATCH v2 05/12] KVM: x86: fast emulate repeat string write instructions References: <4E37DA49.1040000@cn.fujitsu.com> <4E37DADE.1070306@cn.fujitsu.com> In-Reply-To: <4E37DADE.1070306@cn.fujitsu.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/02/2011 02:09 PM, Xiao Guangrong wrote: > We usually use repeat string instructions to clear the page, for example, > we call memset to clear a page table, stosb is used in this function, and > repeated for 1024 times, that means we should occupy mmu lock for 1024 times > and walking shadow page cache for 1024 times, it is terrible > > In fact, if it is the repeat string instructions emulated and it is not a > IO/MMIO access, we can zap all the corresponding shadow pages and return to the > guest, then the mapping can became writable and we can directly write the page > This isn't needed if we zap before emulating, right? -- error compiling committee.c: too many arguments to function