From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F2050C433E6 for ; Tue, 2 Feb 2021 01:33:11 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 92D9364DD6 for ; Tue, 2 Feb 2021 01:33:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 92D9364DD6 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:55362 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1l6kZ4-0007Sz-Eu for qemu-devel@archiver.kernel.org; Mon, 01 Feb 2021 20:33:10 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:50328) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1l6kJt-0000M3-2u; Mon, 01 Feb 2021 20:17:29 -0500 Received: from szxga04-in.huawei.com ([45.249.212.190]:3303) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1l6kJj-0007bn-5s; Mon, 01 Feb 2021 20:17:28 -0500 Received: from DGGEMS407-HUB.china.huawei.com (unknown [172.30.72.58]) by szxga04-in.huawei.com (SkyGuard) with ESMTP id 4DV6Lt4qCSzlDxQ; Tue, 2 Feb 2021 09:15:34 +0800 (CST) Received: from [10.174.184.42] (10.174.184.42) by DGGEMS407-HUB.china.huawei.com (10.3.19.207) with Microsoft SMTP Server id 14.3.498.0; Tue, 2 Feb 2021 09:17:02 +0800 Subject: Re: [PATCH v2 2/2] accel: kvm: Add aligment assert for kvm_log_clear_one_slot To: =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= , Peter Maydell , Paolo Bonzini , "Dr . David Alan Gilbert" , Andrew Jones , "Peter Xu" References: <20201217014941.22872-1-zhukeqian1@huawei.com> <20201217014941.22872-3-zhukeqian1@huawei.com> From: Keqian Zhu Message-ID: <47294e13-c9fe-78c8-db58-eaf0eec9496b@huawei.com> Date: Tue, 2 Feb 2021 09:17:01 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.7.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit X-Originating-IP: [10.174.184.42] X-CFilter-Loop: Reflected Received-SPF: pass client-ip=45.249.212.190; envelope-from=zhukeqian1@huawei.com; helo=szxga04-in.huawei.com X-Spam_score_int: -41 X-Spam_score: -4.2 X-Spam_bar: ---- X-Spam_report: (-4.2 / 5.0 requ) BAYES_00=-1.9, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Zenghui Yu , wanghaibin.wang@huawei.com, jiangkunkun@huawei.com, qemu-devel@nongnu.org, qemu-arm@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Hi Philippe, On 2021/2/1 23:14, Philippe Mathieu-Daudé wrote: > Hi, > > On 12/17/20 2:49 AM, Keqian Zhu wrote: >> The parameters start and size are transfered from QEMU memory >> emulation layer. It can promise that they are TARGET_PAGE_SIZE >> aligned. However, KVM needs they are qemu_real_page_size aligned. >> >> Though no caller breaks this aligned requirement currently, we'd >> better add an explicit assert to avoid future breaking. >> >> Signed-off-by: Keqian Zhu >> --- >> accel/kvm/kvm-all.c | 7 +++++++ >> 1 file changed, 7 insertions(+) >> >> --- >> v2 >> - Address Andrew's commment (Use assert instead of return err). >> >> diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c >> index f6b16a8df8..73b195cc41 100644 >> --- a/accel/kvm/kvm-all.c >> +++ b/accel/kvm/kvm-all.c >> @@ -692,6 +692,10 @@ out: >> #define KVM_CLEAR_LOG_ALIGN (qemu_real_host_page_size << KVM_CLEAR_LOG_SHIFT) >> #define KVM_CLEAR_LOG_MASK (-KVM_CLEAR_LOG_ALIGN) >> >> +/* >> + * As the granule of kvm dirty log is qemu_real_host_page_size, >> + * @start and @size are expected and restricted to align to it. >> + */ >> static int kvm_log_clear_one_slot(KVMSlot *mem, int as_id, uint64_t start, >> uint64_t size) >> { >> @@ -701,6 +705,9 @@ static int kvm_log_clear_one_slot(KVMSlot *mem, int as_id, uint64_t start, >> unsigned long *bmap_clear = NULL, psize = qemu_real_host_page_size; >> int ret; >> >> + /* Make sure start and size are qemu_real_host_page_size aligned */ >> + assert(QEMU_IS_ALIGNED(start | size, psize)); > > Why not return an error instead of aborting the VM? Yep, I return an error in v1. As suggested by Peter Xu: "Returning -EINVAL is the same as abort() currently - it'll just abort() at kvm_log_clear() instead." > >> /* >> * We need to extend either the start or the size or both to >> * satisfy the KVM interface requirement. Firstly, do the start >> > > . > Thanks for review. Keqian.