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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, 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 7E961C33CB1 for ; Sun, 19 Jan 2020 08:09:10 +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 3C0EE20684 for ; Sun, 19 Jan 2020 08:09:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3C0EE20684 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=cn.fujitsu.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:48288 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1it5dt-0002mF-CJ for qemu-devel@archiver.kernel.org; Sun, 19 Jan 2020 03:09:09 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:42468) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1it5dD-0002M0-90 for qemu-devel@nongnu.org; Sun, 19 Jan 2020 03:08:28 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1it5dB-0005Kd-UI for qemu-devel@nongnu.org; Sun, 19 Jan 2020 03:08:27 -0500 Received: from mail.cn.fujitsu.com ([183.91.158.132]:45409 helo=heian.cn.fujitsu.com) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1it5dB-0005Ie-JE for qemu-devel@nongnu.org; Sun, 19 Jan 2020 03:08:25 -0500 X-IronPort-AV: E=Sophos;i="5.70,337,1574092800"; d="scan'208";a="82259448" Received: from unknown (HELO cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 19 Jan 2020 16:08:15 +0800 Received: from G08CNEXMBPEKD06.g08.fujitsu.local (unknown [10.167.33.206]) by cn.fujitsu.com (Postfix) with ESMTP id 1F2ED5010EAF; Sun, 19 Jan 2020 15:59:02 +0800 (CST) Received: from [10.167.220.69] (10.167.220.69) by G08CNEXMBPEKD06.g08.fujitsu.local (10.167.33.206) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Sun, 19 Jan 2020 16:08:10 +0800 Message-ID: <5E240E69.2030803@cn.fujitsu.com> Date: Sun, 19 Jan 2020 16:08:09 +0800 From: Xiao Yang User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.2; zh-CN; rv:1.9.2.18) Gecko/20110616 Thunderbird/3.1.11 MIME-Version: 1.0 To: "Dr. David Alan Gilbert (git)" Subject: Re: [PATCH 040/104] virtiofsd: Pass write iov's all the way through References: <20191212163904.159893-1-dgilbert@redhat.com> <20191212163904.159893-41-dgilbert@redhat.com> In-Reply-To: <20191212163904.159893-41-dgilbert@redhat.com> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.167.220.69] X-ClientProxiedBy: G08CNEXCHPEKD04.g08.fujitsu.local (10.167.33.200) To G08CNEXMBPEKD06.g08.fujitsu.local (10.167.33.206) X-yoursite-MailScanner-ID: 1F2ED5010EAF.AB276 X-yoursite-MailScanner: Found to be clean X-yoursite-MailScanner-From: yangx.jy@cn.fujitsu.com X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 183.91.158.132 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: qemu-devel@nongnu.org, stefanha@redhat.com, vgoyal@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 2019/12/13 0:38, Dr. David Alan Gilbert (git) wrote: > From: "Dr. David Alan Gilbert" > > Pass the write iov pointing to guest RAM all the way through rather > than copying the data. > > Signed-off-by: Dr. David Alan Gilbert > --- > tools/virtiofsd/fuse_virtio.c | 79 ++++++++++++++++++++++++++++++++--- > 1 file changed, 73 insertions(+), 6 deletions(-) > > diff --git a/tools/virtiofsd/fuse_virtio.c b/tools/virtiofsd/fuse_virtio.c > index 99c877ea2e..3c778b6296 100644 > --- a/tools/virtiofsd/fuse_virtio.c > +++ b/tools/virtiofsd/fuse_virtio.c > @@ -452,6 +452,10 @@ static void *fv_queue_thread(void *opaque) > __func__, qi->qidx, (size_t)evalue, in_bytes, out_bytes); > > while (1) { > + bool allocated_bufv = false; > + struct fuse_bufvec bufv; > + struct fuse_bufvec *pbufv; > + > /* > * An element contains one request and the space to send our > * response They're spread over multiple descriptors in a > @@ -493,14 +497,76 @@ static void *fv_queue_thread(void *opaque) > __func__, elem->index); > assert(0); /* TODO */ > } > - copy_from_iov(&fbuf, out_num, out_sg); > - fbuf.size = out_len; > + /* Copy just the first element and look at it */ > + copy_from_iov(&fbuf, 1, out_sg); > + > + if (out_num> 2&& > + out_sg[0].iov_len == sizeof(struct fuse_in_header)&& > + ((struct fuse_in_header *)fbuf.mem)->opcode == FUSE_WRITE&& > + out_sg[1].iov_len == sizeof(struct fuse_write_in)) { > + /* > + * For a write we don't actually need to copy the > + * data, we can just do it straight out of guest memory > + * but we must still copy the headers in case the guest > + * was nasty and changed them while we were using them. > + */ > + fuse_log(FUSE_LOG_DEBUG, "%s: Write special case\n", __func__); > + > + /* copy the fuse_write_in header after the fuse_in_header */ > + fbuf.mem += out_sg->iov_len; > + copy_from_iov(&fbuf, 1, out_sg + 1); > + fbuf.mem -= out_sg->iov_len; > + fbuf.size = out_sg[0].iov_len + out_sg[1].iov_len; > + > + /* Allocate the bufv, with space for the rest of the iov */ > + allocated_bufv = true; > + pbufv = malloc(sizeof(struct fuse_bufvec) + > + sizeof(struct fuse_buf) * (out_num - 2)); > + if (!pbufv) { > + vu_queue_unpop(dev, q, elem, 0); > + free(elem); > + fuse_log(FUSE_LOG_ERR, "%s: pbufv malloc failed\n", > + __func__); > + goto out; > + } > + > + pbufv->count = 1; > + pbufv->buf[0] = fbuf; > + > + size_t iovindex, pbufvindex; > + iovindex = 2; /* 2 headers, separate iovs */ > + pbufvindex = 1; /* 2 headers, 1 fusebuf */ > + > + for (; iovindex< out_num; iovindex++, pbufvindex++) { > + pbufv->count++; > + pbufv->buf[pbufvindex].pos = ~0; /* Dummy */ > + pbufv->buf[pbufvindex].flags = 0; > + pbufv->buf[pbufvindex].mem = out_sg[iovindex].iov_base; > + pbufv->buf[pbufvindex].size = out_sg[iovindex].iov_len; > + } > + } else { > + /* Normal (non fast write) path */ > + > + /* Copy the rest of the buffer */ > + fbuf.mem += out_sg->iov_len; > + copy_from_iov(&fbuf, out_num - 1, out_sg + 1); > + fbuf.mem -= out_sg->iov_len; > + fbuf.size = out_len; > > - /* TODO! Endianness of header */ > + /* TODO! Endianness of header */ > > - /* TODO: Add checks for fuse_session_exited */ > - struct fuse_bufvec bufv = { .buf[0] = fbuf, .count = 1 }; > - fuse_session_process_buf_int(se,&bufv,&ch); > + /* TODO: Add checks for fuse_session_exited */ > + bufv.buf[0] = fbuf; > + bufv.count = 1; > + pbufv =&bufv; > + } > + pbufv->idx = 0; > + pbufv->off = 0; > + fuse_session_process_buf_int(se, pbufv,&ch); > + > + if (allocated_bufv) { > + free(pbufv); > + } > > if (!qi->reply_sent) { > fuse_log(FUSE_LOG_DEBUG, "%s: elem %d no reply sent\n", > @@ -514,6 +580,7 @@ static void *fv_queue_thread(void *opaque) > elem = NULL; > } > } > +out: > pthread_mutex_destroy(&ch.lock); > free(fbuf.mem); > Hi, Tested the patch and got the correct data written by guest, so it looks fine to me. Reviewed-by: Xiao Yang Best Regards, Xiao Yang