From: Fabiano Rosas <farosas@suse.de>
To: "Daniel P. Berrangé" <berrange@redhat.com>
Cc: Markus Armbruster <armbru@redhat.com>,
qemu-devel@nongnu.org, Juan Quintela <quintela@redhat.com>,
Peter Xu <peterx@redhat.com>, Leonardo Bras <leobras@redhat.com>,
Claudio Fontana <cfontana@suse.de>,
Eric Blake <eblake@redhat.com>
Subject: Re: [PATCH v2 28/29] migration: Add direct-io parameter
Date: Wed, 01 Nov 2023 09:30:55 -0300 [thread overview]
Message-ID: <87wmv1fyf4.fsf@suse.de> (raw)
In-Reply-To: <ZUJDQKsg5mMqiMP0@redhat.com>
Daniel P. Berrangé <berrange@redhat.com> writes:
> On Wed, Nov 01, 2023 at 09:16:33AM -0300, Fabiano Rosas wrote:
>> Daniel P. Berrangé <berrange@redhat.com> writes:
>>
>> >
>> > So the problem with add-fd is that when requesting a FD, the monitor
>> > code masks flags with O_ACCMODE. What if we extended it such that
>> > the monitor masked with O_ACCMODE | O_DIRECT.
>> >
>> > That would let us pass 1 plain FD and one O_DIRECT fd, and be able
>> > to ask for each separately by setting O_DIRECT or not.
>>
>> That would likely work. The usage gets a little more complicated, but
>> we'd be using fdset as it was intended.
>>
>> Should we keep the direct-io capability? If the user now needs to set
>> O_DIRECT and also set the cap, that seems a little redundant. I could
>> keep O_DIRECT in the flags (when supported) and test after open if we
>> got the flag set. If it's not set, then we remove O_DIRECT from the
>> flags and retry.
>
> While it is redundant, I like the idea of always requireing the
> direct-io capabilty to be set, as a statement of intent. There's
> a decent chance for apps to mess up with FD passing, and so by
> seeing the 'direct-io' capability we know what the app intended
> todo.
Ok. I'll go write some code then. Thanks for the help!
next prev parent reply other threads:[~2023-11-01 12:32 UTC|newest]
Thread overview: 128+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-23 20:35 [PATCH v2 00/29] migration: File based migration with multifd and fixed-ram Fabiano Rosas
2023-10-23 20:35 ` [PATCH v2 01/29] tests/qtest: migration events Fabiano Rosas
2023-10-25 9:44 ` Thomas Huth
2023-10-25 10:14 ` Daniel P. Berrangé
2023-10-25 13:21 ` Fabiano Rosas
2023-10-25 13:33 ` Steven Sistare
2023-10-23 20:35 ` [PATCH v2 02/29] tests/qtest: Move QTestMigrationState to libqtest Fabiano Rosas
2023-10-25 10:17 ` Daniel P. Berrangé
2023-10-25 13:19 ` Fabiano Rosas
2023-10-23 20:35 ` [PATCH v2 03/29] tests/qtest: Allow waiting for migration events Fabiano Rosas
2023-10-23 20:35 ` [PATCH v2 04/29] migration: Return the saved state from global_state_store Fabiano Rosas
2023-10-25 10:19 ` Daniel P. Berrangé
2023-10-23 20:35 ` [PATCH v2 05/29] migration: Introduce global_state_store_once Fabiano Rosas
2023-10-23 20:35 ` [PATCH v2 06/29] migration: Add auto-pause capability Fabiano Rosas
2023-10-24 5:25 ` Markus Armbruster
2023-10-24 18:12 ` Fabiano Rosas
2023-10-25 5:33 ` Markus Armbruster
2023-10-25 8:48 ` Daniel P. Berrangé
2023-10-25 13:57 ` Fabiano Rosas
2023-10-25 14:20 ` Daniel P. Berrangé
2023-10-25 14:58 ` Peter Xu
2023-10-25 15:25 ` Daniel P. Berrangé
2023-10-25 15:36 ` Peter Xu
2023-10-25 15:40 ` Daniel P. Berrangé
2023-10-25 17:20 ` Peter Xu
2023-10-25 17:31 ` Daniel P. Berrangé
2023-10-25 19:28 ` Peter Xu
2023-10-23 20:35 ` [PATCH v2 07/29] migration: Run "file:" migration with a stopped VM Fabiano Rosas
2023-10-23 20:35 ` [PATCH v2 08/29] tests/qtest: File migration auto-pause tests Fabiano Rosas
2023-10-23 20:35 ` [PATCH v2 09/29] io: add and implement QIO_CHANNEL_FEATURE_SEEKABLE for channel file Fabiano Rosas
2023-10-23 20:35 ` [PATCH v2 10/29] io: Add generic pwritev/preadv interface Fabiano Rosas
2023-10-24 8:18 ` Daniel P. Berrangé
2023-10-24 19:06 ` Fabiano Rosas
2023-10-23 20:35 ` [PATCH v2 11/29] io: implement io_pwritev/preadv for QIOChannelFile Fabiano Rosas
2023-10-23 20:35 ` [PATCH v2 12/29] migration/qemu-file: add utility methods for working with seekable channels Fabiano Rosas
2023-10-25 10:22 ` Daniel P. Berrangé
2023-10-23 20:35 ` [PATCH v2 13/29] migration: fixed-ram: Add URI compatibility check Fabiano Rosas
2023-10-25 10:27 ` Daniel P. Berrangé
2023-10-31 16:06 ` Peter Xu
2023-10-23 20:35 ` [PATCH v2 14/29] migration/ram: Introduce 'fixed-ram' migration capability Fabiano Rosas
2023-10-24 5:33 ` Markus Armbruster
2023-10-24 18:35 ` Fabiano Rosas
2023-10-25 6:18 ` Markus Armbruster
2023-10-23 20:35 ` [PATCH v2 15/29] migration/ram: Add support for 'fixed-ram' outgoing migration Fabiano Rosas
2023-10-25 9:39 ` Daniel P. Berrangé
2023-10-25 14:03 ` Fabiano Rosas
2023-11-01 15:23 ` Peter Xu
2023-11-01 15:52 ` Daniel P. Berrangé
2023-11-01 16:24 ` Peter Xu
2023-11-01 16:37 ` Daniel P. Berrangé
2023-11-01 17:30 ` Peter Xu
2023-10-31 16:52 ` Peter Xu
2023-10-31 17:33 ` Fabiano Rosas
2023-10-31 17:59 ` Peter Xu
2023-10-23 20:35 ` [PATCH v2 16/29] migration/ram: Add support for 'fixed-ram' migration restore Fabiano Rosas
2023-10-25 9:43 ` Daniel P. Berrangé
2023-10-25 14:07 ` Fabiano Rosas
2023-10-31 19:03 ` Peter Xu
2023-11-01 9:26 ` Daniel P. Berrangé
2023-11-01 14:21 ` Peter Xu
2023-11-01 14:28 ` Daniel P. Berrangé
2023-11-01 15:00 ` Peter Xu
2023-11-06 13:18 ` Fabiano Rosas
2023-11-06 21:00 ` Peter Xu
2023-11-07 9:02 ` Daniel P. Berrangé
2023-10-31 19:09 ` Peter Xu
2023-10-31 20:00 ` Fabiano Rosas
2023-10-23 20:35 ` [PATCH v2 17/29] tests/qtest: migration-test: Add tests for fixed-ram file-based migration Fabiano Rosas
2023-10-23 20:35 ` [PATCH v2 18/29] migration/multifd: Allow multifd without packets Fabiano Rosas
2023-10-23 20:35 ` [PATCH v2 19/29] migration/multifd: Add outgoing QIOChannelFile support Fabiano Rosas
2023-10-25 9:52 ` Daniel P. Berrangé
2023-10-25 14:12 ` Fabiano Rosas
2023-10-25 14:23 ` Daniel P. Berrangé
2023-10-25 15:00 ` Fabiano Rosas
2023-10-25 15:26 ` Daniel P. Berrangé
2023-10-31 20:11 ` Peter Xu
2023-10-23 20:35 ` [PATCH v2 20/29] migration/multifd: Add incoming " Fabiano Rosas
2023-10-25 10:29 ` Daniel P. Berrangé
2023-10-25 14:18 ` Fabiano Rosas
2023-10-31 21:28 ` Peter Xu
2023-10-23 20:36 ` [PATCH v2 21/29] migration/multifd: Add pages to the receiving side Fabiano Rosas
2023-10-31 22:10 ` Peter Xu
2023-10-31 23:18 ` Fabiano Rosas
2023-11-01 15:55 ` Peter Xu
2023-11-01 17:20 ` Fabiano Rosas
2023-11-01 17:35 ` Peter Xu
2023-11-01 18:14 ` Fabiano Rosas
2023-10-23 20:36 ` [PATCH v2 22/29] io: Add a pwritev/preadv version that takes a discontiguous iovec Fabiano Rosas
2023-10-24 8:50 ` Daniel P. Berrangé
2023-10-23 20:36 ` [PATCH v2 23/29] migration/ram: Add a wrapper for fixed-ram shadow bitmap Fabiano Rosas
2023-11-01 14:29 ` Peter Xu
2023-10-23 20:36 ` [PATCH v2 24/29] migration/ram: Ignore multifd flush when doing fixed-ram migration Fabiano Rosas
2023-10-25 9:09 ` Daniel P. Berrangé
2023-10-23 20:36 ` [PATCH v2 25/29] migration/multifd: Support outgoing fixed-ram stream format Fabiano Rosas
2023-10-25 9:23 ` Daniel P. Berrangé
2023-10-25 14:21 ` Fabiano Rosas
2023-10-23 20:36 ` [PATCH v2 26/29] migration/multifd: Support incoming " Fabiano Rosas
2023-10-23 20:36 ` [PATCH v2 27/29] tests/qtest: Add a multifd + fixed-ram migration test Fabiano Rosas
2023-10-23 20:36 ` [PATCH v2 28/29] migration: Add direct-io parameter Fabiano Rosas
2023-10-24 5:41 ` Markus Armbruster
2023-10-24 19:32 ` Fabiano Rosas
2023-10-25 6:23 ` Markus Armbruster
2023-10-25 8:44 ` Daniel P. Berrangé
2023-10-25 14:32 ` Fabiano Rosas
2023-10-25 14:43 ` Daniel P. Berrangé
2023-10-25 17:30 ` Fabiano Rosas
2023-10-25 17:45 ` Daniel P. Berrangé
2023-10-25 18:10 ` Fabiano Rosas
2023-10-30 22:51 ` Fabiano Rosas
2023-10-31 9:03 ` Daniel P. Berrangé
2023-10-31 13:05 ` Fabiano Rosas
2023-10-31 13:45 ` Daniel P. Berrangé
2023-10-31 14:33 ` Fabiano Rosas
2023-10-31 15:22 ` Daniel P. Berrangé
2023-10-31 15:52 ` Fabiano Rosas
2023-10-31 15:58 ` Daniel P. Berrangé
2023-10-31 19:05 ` Fabiano Rosas
2023-11-01 9:30 ` Daniel P. Berrangé
2023-11-01 12:16 ` Fabiano Rosas
2023-11-01 12:23 ` Daniel P. Berrangé
2023-11-01 12:30 ` Fabiano Rosas [this message]
2023-10-24 8:33 ` Daniel P. Berrangé
2023-10-24 19:06 ` Fabiano Rosas
2023-10-25 9:07 ` Daniel P. Berrangé
2023-10-25 14:48 ` Fabiano Rosas
2023-10-25 15:22 ` Daniel P. Berrangé
2023-10-23 20:36 ` [PATCH v2 29/29] tests/qtest: Add a test for migration with direct-io and multifd Fabiano Rosas
2023-10-25 9:25 ` Daniel P. Berrangé
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