From nobody Sat Feb 7 08:58:32 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1500289899218305.31304552523613; Mon, 17 Jul 2017 04:11:39 -0700 (PDT) Received: from localhost ([::1]:49445 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dX3w8-00047W-Ph for importer@patchew.org; Mon, 17 Jul 2017 07:11:36 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53719) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dX3uV-0002zT-2a for qemu-devel@nongnu.org; Mon, 17 Jul 2017 07:09:56 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dX3uQ-0002sn-Sn for qemu-devel@nongnu.org; Mon, 17 Jul 2017 07:09:55 -0400 Received: from mx1.redhat.com ([209.132.183.28]:35610) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dX3uQ-0002sM-JX for qemu-devel@nongnu.org; Mon, 17 Jul 2017 07:09:50 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id AB20F4E03F for ; Mon, 17 Jul 2017 11:09:49 +0000 (UTC) Received: from dgilbert-t530.redhat.com (ovpn-117-162.ams2.redhat.com [10.36.117.162]) by smtp.corp.redhat.com (Postfix) with ESMTP id 11FF570952; Mon, 17 Jul 2017 11:09:43 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com AB20F4E03F Authentication-Results: ext-mx09.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx09.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=dgilbert@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com AB20F4E03F From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org Date: Mon, 17 Jul 2017 12:09:34 +0100 Message-Id: <20170717110936.23314-5-dgilbert@redhat.com> In-Reply-To: <20170717110936.23314-1-dgilbert@redhat.com> References: <20170717110936.23314-1-dgilbert@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Mon, 17 Jul 2017 11:09:49 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v4 4/6] migration/rdma: Allow cancelling while waiting for wrid X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: lvivier@redhat.com, peterx@redhat.com, quintela@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: "Dr. David Alan Gilbert" When waiting for a WRID, if the other side dies we end up waiting for ever with no way to cancel the migration. Cure this by poll()ing the fd first with a timeout and checking error flags and migration state. Signed-off-by: Dr. David Alan Gilbert Reviewed-by: Peter Xu --- migration/rdma.c | 59 ++++++++++++++++++++++++++++++++++++++++++++++++++--= ---- 1 file changed, 53 insertions(+), 6 deletions(-) diff --git a/migration/rdma.c b/migration/rdma.c index 59810aec2e..0cf55a6d5b 100644 --- a/migration/rdma.c +++ b/migration/rdma.c @@ -1466,6 +1466,56 @@ static uint64_t qemu_rdma_poll(RDMAContext *rdma, ui= nt64_t *wr_id_out, return 0; } =20 +/* Wait for activity on the completion channel. + * Returns 0 on success, none-0 on error. + */ +static int qemu_rdma_wait_comp_channel(RDMAContext *rdma) +{ + /* + * Coroutine doesn't start until migration_fd_process_incoming() + * so don't yield unless we know we're running inside of a coroutine. + */ + if (rdma->migration_started_on_destination) { + yield_until_fd_readable(rdma->comp_channel->fd); + } else { + /* This is the source side, we're in a separate thread + * or destination prior to migration_fd_process_incoming() + * we can't yield; so we have to poll the fd. + * But we need to be able to handle 'cancel' or an error + * without hanging forever. + */ + while (!rdma->error_state && !rdma->received_error) { + GPollFD pfds[1]; + pfds[0].fd =3D rdma->comp_channel->fd; + pfds[0].events =3D G_IO_IN | G_IO_HUP | G_IO_ERR; + /* 0.1s timeout, should be fine for a 'cancel' */ + switch (qemu_poll_ns(pfds, 1, 100 * 1000 * 1000)) { + case 1: /* fd active */ + return 0; + + case 0: /* Timeout, go around again */ + break; + + default: /* Error of some type - + * I don't trust errno from qemu_poll_ns + */ + error_report("%s: poll failed", __func__); + return -EPIPE; + } + + if (migrate_get_current()->state =3D=3D MIGRATION_STATUS_CANCE= LLING) { + /* Bail out and let the cancellation happen */ + return -EPIPE; + } + } + } + + if (rdma->received_error) { + return -EPIPE; + } + return rdma->error_state; +} + /* * Block until the next work request has completed. * @@ -1513,12 +1563,9 @@ static int qemu_rdma_block_for_wrid(RDMAContext *rdm= a, int wrid_requested, } =20 while (1) { - /* - * Coroutine doesn't start until migration_fd_process_incoming() - * so don't yield unless we know we're running inside of a corouti= ne. - */ - if (rdma->migration_started_on_destination) { - yield_until_fd_readable(rdma->comp_channel->fd); + ret =3D qemu_rdma_wait_comp_channel(rdma); + if (ret) { + goto err_block_for_wrid; } =20 ret =3D ibv_get_cq_event(rdma->comp_channel, &cq, &cq_ctx); --=20 2.13.0