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 Received: from lists1p.gnu.org (lists1p.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 5C319CD98EE for ; Wed, 17 Jun 2026 06:44:10 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1wZk0I-00053J-1A; Wed, 17 Jun 2026 02:44:02 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists1p.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1wZk07-00050i-V9 for qemu-devel@nongnu.org; Wed, 17 Jun 2026 02:43:52 -0400 Received: from [115.124.30.98] (helo=out30-98.freemail.mail.aliyun.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1wZk03-00087l-Vv for qemu-devel@nongnu.org; Wed, 17 Jun 2026 02:43:51 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1781678614; h=From:To:Subject:Date:Message-ID:MIME-Version; bh=CdH+sNES2FdBHJISfag0GHIwn/jVXYTmNClZbL3Udf8=; b=Kfj2ecmOK/hmjGVR1zEhQZ2UOleVwl7lS7D/zoXLxEYPAB9EdDGLjxkSYWOVqNxUxc4DxUz3A8Jzj8G/yHdHOrfT/a8PyGccm2R3UiYnZYRk6KkDLHDCI5I5fh2aHXxg0qnqUFmTqRuQTVbSpveborr8hdvHFNxLTlfZlum1fK0= X-Alimail-AntiSpam: AC=PASS; BC=-1|-1; BR=01201311R811e4; CH=green; DM=||false|; DS=||; FP=0|-1|-1|-1|0|-1|-1|-1; HT=maildocker-contentspam033032089153; MF=guobin@linux.alibaba.com; NM=1; PH=DS; RN=4; SR=0; TI=SMTPD_---0X52TpQC_1781678613; Received: from localhost(mailfrom:guobin@linux.alibaba.com fp:SMTPD_---0X52TpQC_1781678613 cluster:ay36) by smtp.aliyun-inc.com; Wed, 17 Jun 2026 14:43:33 +0800 From: Bin Guo To: qemu-devel@nongnu.org Cc: peterx@redhat.com, lizhijian@fujitsu.com, farosas@suse.de Subject: [PATCH v2 1/2] migration/rdma: honor blocking mode in QIOChannelRDMA readv Date: Wed, 17 Jun 2026 14:43:31 +0800 Message-ID: <20260617064332.75618-1-guobin@linux.alibaba.com> X-Mailer: git-send-email 2.50.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Host-Lookup-Failed: Reverse DNS lookup failed for 115.124.30.98 (deferred) Received-SPF: pass client-ip=115.124.30.98; envelope-from=guobin@linux.alibaba.com; helo=out30-98.freemail.mail.aliyun.com X-Spam_score_int: -166 X-Spam_score: -16.7 X-Spam_bar: ---------------- X-Spam_report: (-16.7 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, ENV_AND_HDR_SPF_MATCH=-0.5, RCVD_IN_DNSWL_NONE=-0.0001, RDNS_NONE=0.793, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, UNPARSEABLE_RELAY=0.001, USER_IN_DEF_DKIM_WL=-7.5, USER_IN_DEF_SPF_WL=-7.5 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: qemu development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org QIOChannelRDMA's readv already blocks inside qemu_rdma_exchange_recv() when waiting for the next RDMA SEND message. What it did not do was keep blocking when the bytes from a single receive were insufficient to satisfy the full request -- it returned partial data (or EAGAIN) instead of waiting for more. Loop on qemu_rdma_exchange_recv() when the channel is blocking and the receive buffer cannot satisfy the request. This matches the behaviour of other QIOChannel implementations, which block until the full request is satisfied (or an error occurs). Also remove the stale XXX comments about unimplemented blocking support. Reviewed-by: Li Zhijian Signed-off-by: Bin Guo --- migration/rdma.c | 46 +++++++++++++++++++++------------------------- 1 file changed, 21 insertions(+), 25 deletions(-) diff --git a/migration/rdma.c b/migration/rdma.c index 3e37a1d440..201cb9eb12 100644 --- a/migration/rdma.c +++ b/migration/rdma.c @@ -388,7 +388,7 @@ struct QIOChannelRDMA { QIOChannel parent; RDMAContext *rdmain; RDMAContext *rdmaout; - bool blocking; /* XXX we don't actually honour this yet */ + bool blocking; }; /* @@ -2710,32 +2710,29 @@ static ssize_t qio_channel_rdma_readv(QIOChannel *ioc, break; } - - /* We've got nothing at all, so lets wait for - * more to arrive - */ - ret = qemu_rdma_exchange_recv(rdma, &head, RDMA_CONTROL_QEMU_FILE, - errp); - - if (ret < 0) { - rdma->errored = true; - return -1; - } - /* - * SEND was received with new bytes, now try again. + * We've got nothing at all, so lets wait for + * more to arrive. */ - len = qemu_rdma_fill(rdma, data, want, 0); - done += len; - want -= len; - - /* Still didn't get enough, so lets just return */ - if (want) { - if (done == 0) { - return QIO_CHANNEL_ERR_BLOCK; - } else { - break; + do { + ret = qemu_rdma_exchange_recv(rdma, &head, + RDMA_CONTROL_QEMU_FILE, errp); + if (ret < 0) { + rdma->errored = true; + return -1; } + + /* + * SEND was received with new bytes, now try again. + */ + len = qemu_rdma_fill(rdma, data, want, 0); + done += len; + want -= len; + data += len; + } while (want && rioc->blocking); + + if (want && done == 0) { + return QIO_CHANNEL_ERR_BLOCK; } } return done; @@ -2771,7 +2768,6 @@ static int qio_channel_rdma_set_blocking(QIOChannel *ioc, Error **errp) { QIOChannelRDMA *rioc = QIO_CHANNEL_RDMA(ioc); - /* XXX we should make readv/writev actually honour this :-) */ rioc->blocking = blocking; return 0; } -- 2.50.1 (Apple Git-155)