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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 2AA89C0032E for ; Wed, 25 Oct 2023 14:24:30 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qvenp-00044r-UP; Wed, 25 Oct 2023 10:24:09 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qveno-00044i-V7 for qemu-devel@nongnu.org; Wed, 25 Oct 2023 10:24:09 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qvenn-0001pN-6k for qemu-devel@nongnu.org; Wed, 25 Oct 2023 10:24:08 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1698243846; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=v/+PBBJ8tn9e2TDajLDfWcB1zmWW7pZrPjEnApElhTo=; b=NnJouwd+S/jDgqS/CKfXuOQjydJwf6b2r/9a6+0saVpjQphRuGc6uJOgcbU0hOvI1gRpt0 88vjWv09vS002dcI5Sp5R/DB+Vqacimmg9qhRX6ETO2rVDsk8K/y8FOEfftHEW/pLJiBRN P1dvTm9N07oyCQbgx3LeI+uYb3KTPns= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-225-iPozLzG6PS6FJC-24F_wlQ-1; Wed, 25 Oct 2023 10:23:52 -0400 X-MC-Unique: iPozLzG6PS6FJC-24F_wlQ-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 8690B3C1E9D0; Wed, 25 Oct 2023 14:23:51 +0000 (UTC) Received: from redhat.com (unknown [10.42.28.154]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 6EAE2131; Wed, 25 Oct 2023 14:23:50 +0000 (UTC) Date: Wed, 25 Oct 2023 15:23:48 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Fabiano Rosas Cc: qemu-devel@nongnu.org, armbru@redhat.com, Juan Quintela , Peter Xu , Leonardo Bras , Claudio Fontana Subject: Re: [PATCH v2 19/29] migration/multifd: Add outgoing QIOChannelFile support Message-ID: References: <20231023203608.26370-1-farosas@suse.de> <20231023203608.26370-20-farosas@suse.de> <87o7gmeqp5.fsf@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <87o7gmeqp5.fsf@suse.de> User-Agent: Mutt/2.2.9 (2022-11-12) X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.1 Received-SPF: pass client-ip=170.10.129.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, 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: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Wed, Oct 25, 2023 at 11:12:38AM -0300, Fabiano Rosas wrote: > Daniel P. Berrangé writes: > > > On Mon, Oct 23, 2023 at 05:35:58PM -0300, Fabiano Rosas wrote: > >> Allow multifd to open file-backed channels. This will be used when > >> enabling the fixed-ram migration stream format which expects a > >> seekable transport. > >> > >> The QIOChannel read and write methods will use the preadv/pwritev > >> versions which don't update the file offset at each call so we can > >> reuse the fd without re-opening for every channel. > >> > >> Note that this is just setup code and multifd cannot yet make use of > >> the file channels. > >> > >> Signed-off-by: Fabiano Rosas > >> --- > >> migration/file.c | 64 +++++++++++++++++++++++++++++++++++++++++-- > >> migration/file.h | 10 +++++-- > >> migration/migration.c | 2 +- > >> migration/multifd.c | 14 ++++++++-- > >> migration/options.c | 7 +++++ > >> migration/options.h | 1 + > >> 6 files changed, 90 insertions(+), 8 deletions(-) > >> > >> diff --git a/migration/file.c b/migration/file.c > >> index cf5b1bf365..93b9b7bf5d 100644 > >> --- a/migration/file.c > >> +++ b/migration/file.c > >> @@ -17,6 +17,12 @@ > > > >> +void file_send_channel_create(QIOTaskFunc f, void *data) > >> +{ > >> + QIOChannelFile *ioc; > >> + QIOTask *task; > >> + Error *errp = NULL; > >> + > >> + ioc = qio_channel_file_new_path(outgoing_args.fname, > >> + outgoing_args.flags, > >> + outgoing_args.mode, &errp); > >> + if (!ioc) { > >> + file_migration_cancel(errp); > >> + return; > >> + } > >> + > >> + task = qio_task_new(OBJECT(ioc), f, (gpointer)data, NULL); > >> + qio_task_run_in_thread(task, qio_channel_file_connect_worker, > >> + (gpointer)data, NULL, NULL); > >> +} > >> + > >> void file_start_outgoing_migration(MigrationState *s, const char *filespec, > >> Error **errp) > >> { > >> - g_autofree char *filename = g_strdup(filespec); > >> g_autoptr(QIOChannelFile) fioc = NULL; > >> + g_autofree char *filename = g_strdup(filespec); > >> uint64_t offset = 0; > >> QIOChannel *ioc; > >> + int flags = O_CREAT | O_TRUNC | O_WRONLY; > >> + mode_t mode = 0660; > >> > >> trace_migration_file_outgoing(filename); > >> > >> @@ -50,12 +105,15 @@ void file_start_outgoing_migration(MigrationState *s, const char *filespec, > >> return; > >> } > >> > >> - fioc = qio_channel_file_new_path(filename, O_CREAT | O_WRONLY | O_TRUNC, > >> - 0600, errp); > > By the way, we're experimenting with add-fd to flesh out the interface > with libvirt and I see that the flags here can conflict with the flags > set on the fd passed through `virsh --pass-fd ...` due to this at > monitor_fdset_dup_fd_add(): > > if ((flags & O_ACCMODE) == (mon_fd_flags & O_ACCMODE)) { > fd = mon_fdset_fd->fd; > break; > } > > We're requiring the O_RDONLY, O_WRONLY, O_RDWR flags defined here to > match the fdset passed into QEMU. Should we just sync the code of the > two projects to use the same flags? That feels a little clumsy to me. Is there a reason for libvirt to have set O_RDONLY for a file used for outgoing migration ? I can't recall off-hand. If we document the required O_ACCMODE against the 'file' address schema in QAPI, I don't think it'd be too painful for mgmt apps. With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|