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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 87F12C43461 for ; Wed, 16 Sep 2020 09:04:28 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (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 4A12120738 for ; Wed, 16 Sep 2020 09:04:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4A12120738 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kITME-0004Pq-0I; Wed, 16 Sep 2020 09:04:06 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kITMD-0004Pl-3j for xen-devel@lists.xenproject.org; Wed, 16 Sep 2020 09:04:05 +0000 X-Inumbo-ID: b1bd6ea1-53c5-46d0-8cfa-3e89c0a66cdb Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id b1bd6ea1-53c5-46d0-8cfa-3e89c0a66cdb; Wed, 16 Sep 2020 09:04:04 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id C6725AC97; Wed, 16 Sep 2020 09:04:18 +0000 (UTC) Subject: Re: [PATCH V1 14/16] xen/ioreq: Use guest_cmpxchg64() instead of cmpxchg() To: Oleksandr Tyshchenko Cc: xen-devel@lists.xenproject.org, Oleksandr Tyshchenko , Paul Durrant , Julien Grall , Stefano Stabellini , Julien Grall References: <1599769330-17656-1-git-send-email-olekstysh@gmail.com> <1599769330-17656-15-git-send-email-olekstysh@gmail.com> From: Jan Beulich Message-ID: <44b19ee1-dc34-3a46-0b4b-7196faadcb5c@suse.com> Date: Wed, 16 Sep 2020 11:04:03 +0200 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 MIME-Version: 1.0 In-Reply-To: <1599769330-17656-15-git-send-email-olekstysh@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" On 10.09.2020 22:22, Oleksandr Tyshchenko wrote: > @@ -1325,7 +1327,7 @@ static int hvm_send_buffered_ioreq(struct hvm_ioreq_server *s, ioreq_t *p) > > new.read_pointer = old.read_pointer - n * IOREQ_BUFFER_SLOT_NUM; > new.write_pointer = old.write_pointer - n * IOREQ_BUFFER_SLOT_NUM; > - cmpxchg(&pg->ptrs.full, old.full, new.full); > + guest_cmpxchg64(d, &pg->ptrs.full, old.full, new.full); But the memory we're updating is shared with s->emulator, not with d, if I'm not mistaken. Jan