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 5F5B5C0032E for ; Wed, 25 Oct 2023 14:14:00 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qvecy-0006eI-8i; Wed, 25 Oct 2023 10:12:56 -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 1qvecs-0006Ug-M0 for qemu-devel@nongnu.org; Wed, 25 Oct 2023 10:12:52 -0400 Received: from smtp-out2.suse.de ([195.135.220.29]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1qvecl-000806-TL for qemu-devel@nongnu.org; Wed, 25 Oct 2023 10:12:50 -0400 Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id A12601FF65; Wed, 25 Oct 2023 14:12:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1698243161; h=from:from:reply-to: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=JMPgB6joPC0caz/SqECLK1Sx7xOT92d+jRK8fgW/10o=; b=t0FzZHxZwIJ8j8s/770wGEz/eZe8k78UGx5WulXcdtZcSR+k8ma7mNxie8RsguEB78R4k7 41t6OzqHF3TcFR4uhXfpVtwZrP3whbC3D51s3j9stG2cz9O+vwM2iUHmvDxF2fBY02ECdW ytK1941rZHz2vtc7ii53giMQ6GjGC3A= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1698243161; h=from:from:reply-to: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=JMPgB6joPC0caz/SqECLK1Sx7xOT92d+jRK8fgW/10o=; b=nFyjkgey8ECd80J0hqgQ5EA7o4karcbb4+4ysNErVYmEkPK3uU1dXXpxPQZ4KG5oXh4IpT 7pbUviRC8Wi81jDA== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 33DCF138E9; Wed, 25 Oct 2023 14:12:41 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id EtBzAFkiOWVLFgAAMHmgww (envelope-from ); Wed, 25 Oct 2023 14:12:41 +0000 From: Fabiano Rosas To: =?utf-8?Q?Daniel_P=2E_Berrang=C3=A9?= 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 In-Reply-To: References: <20231023203608.26370-1-farosas@suse.de> <20231023203608.26370-20-farosas@suse.de> Date: Wed, 25 Oct 2023 11:12:38 -0300 Message-ID: <87o7gmeqp5.fsf@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Authentication-Results: smtp-out2.suse.de; none X-Spamd-Result: default: False [-7.10 / 50.00]; ARC_NA(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; BAYES_HAM(-3.00)[100.00%]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; NEURAL_HAM_LONG(-3.00)[-1.000]; MIME_GOOD(-0.10)[text/plain]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; NEURAL_HAM_SHORT(-1.00)[-1.000]; RCPT_COUNT_SEVEN(0.00)[7]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+]; RCVD_COUNT_TWO(0.00)[2]; RCVD_TLS_ALL(0.00)[]; MID_RHS_MATCH_FROM(0.00)[] Received-SPF: pass client-ip=195.135.220.29; envelope-from=farosas@suse.de; helo=smtp-out2.suse.de X-Spam_score_int: -43 X-Spam_score: -4.4 X-Spam_bar: ---- X-Spam_report: (-4.4 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_MED=-2.3, 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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Daniel P. Berrang=C3=A9 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. >>=20 >> 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. >>=20 >> Note that this is just setup code and multifd cannot yet make use of >> the file channels. >>=20 >> 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(-) >>=20 >> 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 =3D NULL; >> + >> + ioc =3D qio_channel_file_new_path(outgoing_args.fname, >> + outgoing_args.flags, >> + outgoing_args.mode, &errp); >> + if (!ioc) { >> + file_migration_cancel(errp); >> + return; >> + } >> + >> + task =3D 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 *files= pec, >> Error **errp) >> { >> - g_autofree char *filename =3D g_strdup(filespec); >> g_autoptr(QIOChannelFile) fioc =3D NULL; >> + g_autofree char *filename =3D g_strdup(filespec); >> uint64_t offset =3D 0; >> QIOChannel *ioc; >> + int flags =3D O_CREAT | O_TRUNC | O_WRONLY; >> + mode_t mode =3D 0660; >>=20=20 >> trace_migration_file_outgoing(filename); >>=20=20 >> @@ -50,12 +105,15 @@ void file_start_outgoing_migration(MigrationState *= s, const char *filespec, >> return; >> } >>=20=20 >> - fioc =3D 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) =3D=3D (mon_fd_flags & O_ACCMODE)) { fd =3D 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. >> + fioc =3D qio_channel_file_new_path(filename, flags, mode, errp); > > So this initially opens the file with O_CREAT|O_TRUNC which > makes sense. > >> if (!fioc) { >> return; >> } >>=20=20 >> + outgoing_args.fname =3D g_strdup(filename); >> + outgoing_args.flags =3D flags; >> + outgoing_args.mode =3D mode; > > We're passing on O_CREAT|O_TRUNC to all the multifd threads too. This > doesn't make sense to me - the file should already exist and be truncated > by the time the threads open it. I would think they should only be using > O_WRONLY and no mode at all. > Ok.