From: Alex Williamson <alex.williamson@redhat.com>
To: Jason Gunthorpe <jgg@nvidia.com>
Cc: Avihai Horon <avihaih@nvidia.com>,
qemu-devel@nongnu.org, Halil Pasic <pasic@linux.ibm.com>,
Christian Borntraeger <borntraeger@linux.ibm.com>,
Eric Farman <farman@linux.ibm.com>,
Richard Henderson <richard.henderson@linaro.org>,
David Hildenbrand <david@redhat.com>,
Ilya Leoshkevich <iii@linux.ibm.com>,
Thomas Huth <thuth@redhat.com>,
Juan Quintela <quintela@redhat.com>,
"Dr. David Alan Gilbert" <dgilbert@redhat.com>,
"Michael S. Tsirkin" <mst@redhat.com>,
Cornelia Huck <cohuck@redhat.com>,
Paolo Bonzini <pbonzini@redhat.com>,
Stefan Hajnoczi <stefanha@redhat.com>, Fam Zheng <fam@euphon.net>,
Eric Blake <eblake@redhat.com>,
Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>,
John Snow <jsnow@redhat.com>,
qemu-s390x@nongnu.org, qemu-block@nongnu.org,
Kunkun Jiang <jiangkunkun@huawei.com>,
"Zhang, Chen" <chen.zhang@intel.com>,
Yishai Hadas <yishaih@nvidia.com>,
Maor Gottlieb <maorg@nvidia.com>, Shay Drory <shayd@nvidia.com>,
Kirti Wankhede <kwankhede@nvidia.com>,
Tarun Gupta <targupta@nvidia.com>,
Joao Martins <joao.m.martins@oracle.com>
Subject: Re: [PATCH v3 12/17] vfio/migration: Implement VFIO migration protocol v2
Date: Mon, 28 Nov 2022 13:36:30 -0700 [thread overview]
Message-ID: <20221128133630.07e1fa14.alex.williamson@redhat.com> (raw)
In-Reply-To: <Y4UOp7Wi/fwsY6DY@nvidia.com>
On Mon, 28 Nov 2022 15:40:23 -0400
Jason Gunthorpe <jgg@nvidia.com> wrote:
> On Mon, Nov 28, 2022 at 11:50:03AM -0700, Alex Williamson wrote:
>
> > There's a claim here about added complexity that I'm not really seeing.
> > It looks like we simply make an ioctl call here and scale our buffer
> > based on the minimum of the returned device estimate or our upper
> > bound.
>
> I'm not keen on this, for something like mlx5 that has a small precopy
> size and large post-copy size it risks running with an under allocated
> buffer, which is harmful to performance.
I'm trying to weed out whether there are device assumptions in the
implementation, seems like maybe we found one. MIG_DATA_SIZE specifies
that it's an estimated data size for stop-copy, so shouldn't that
provide the buffer size you're looking for? Thanks,
Alex
next prev parent reply other threads:[~2022-11-28 20:37 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-03 16:16 [PATCH v3 00/17] vfio/migration: Implement VFIO migration protocol v2 Avihai Horon
2022-11-03 16:16 ` [PATCH v3 01/17] migration: Remove res_compatible parameter Avihai Horon
2022-11-08 17:52 ` Vladimir Sementsov-Ogievskiy
2022-11-10 13:36 ` Avihai Horon
2022-11-21 7:20 ` Avihai Horon
2022-11-23 18:23 ` Dr. David Alan Gilbert
2022-11-24 12:19 ` Avihai Horon
2022-11-03 16:16 ` [PATCH v3 02/17] migration: No save_live_pending() method uses the QEMUFile parameter Avihai Horon
2022-11-08 17:57 ` Vladimir Sementsov-Ogievskiy
2022-11-03 16:16 ` [PATCH v3 03/17] migration: Block migration comment or code is wrong Avihai Horon
2022-11-08 18:36 ` Vladimir Sementsov-Ogievskiy
2022-11-08 18:38 ` Vladimir Sementsov-Ogievskiy
2022-11-10 13:38 ` Avihai Horon
2022-11-21 7:21 ` Avihai Horon
2022-11-03 16:16 ` [PATCH v3 04/17] migration: Simplify migration_iteration_run() Avihai Horon
2022-11-08 18:56 ` Vladimir Sementsov-Ogievskiy
2022-11-10 13:42 ` Avihai Horon
2022-11-03 16:16 ` [PATCH v3 05/17] vfio/migration: Fix wrong enum usage Avihai Horon
2022-11-08 19:05 ` Vladimir Sementsov-Ogievskiy
2022-11-10 13:47 ` Avihai Horon
2022-11-03 16:16 ` [PATCH v3 06/17] vfio/migration: Fix NULL pointer dereference bug Avihai Horon
2022-11-08 19:08 ` Vladimir Sementsov-Ogievskiy
2022-11-03 16:16 ` [PATCH v3 07/17] vfio/migration: Allow migration without VFIO IOMMU dirty tracking support Avihai Horon
2022-11-15 23:36 ` Alex Williamson
2022-11-16 13:29 ` Avihai Horon
2022-11-03 16:16 ` [PATCH v3 08/17] migration/qemu-file: Add qemu_file_get_to_fd() Avihai Horon
2022-11-08 20:26 ` Vladimir Sementsov-Ogievskiy
2022-11-03 16:16 ` [PATCH v3 09/17] vfio/common: Change vfio_devices_all_running_and_saving() logic to equivalent one Avihai Horon
2022-11-03 16:16 ` [PATCH v3 10/17] vfio/migration: Move migration v1 logic to vfio_migration_init() Avihai Horon
2022-11-15 23:56 ` Alex Williamson
2022-11-16 13:39 ` Avihai Horon
2022-11-03 16:16 ` [PATCH v3 11/17] vfio/migration: Rename functions/structs related to v1 protocol Avihai Horon
2022-11-03 16:16 ` [PATCH v3 12/17] vfio/migration: Implement VFIO migration protocol v2 Avihai Horon
2022-11-16 18:29 ` Alex Williamson
2022-11-17 17:07 ` Avihai Horon
2022-11-17 17:24 ` Jason Gunthorpe
2022-11-20 8:46 ` Avihai Horon
2022-11-17 17:38 ` Alex Williamson
2022-11-20 9:34 ` Avihai Horon
2022-11-24 12:41 ` Avihai Horon
2022-11-28 18:50 ` Alex Williamson
2022-11-28 19:40 ` Jason Gunthorpe
2022-11-28 20:36 ` Alex Williamson [this message]
2022-11-28 20:56 ` Jason Gunthorpe
2022-11-28 21:10 ` Alex Williamson
2022-11-29 10:40 ` Avihai Horon
2022-11-23 18:59 ` Dr. David Alan Gilbert
2022-11-24 12:25 ` Avihai Horon
2022-11-24 13:28 ` Dr. David Alan Gilbert
2022-11-24 14:07 ` Avihai Horon
2022-11-03 16:16 ` [PATCH v3 13/17] vfio/migration: Remove VFIO migration protocol v1 Avihai Horon
2022-11-03 16:16 ` [PATCH v3 14/17] vfio/migration: Reset device if setting recover state fails Avihai Horon
2022-11-16 18:36 ` Alex Williamson
2022-11-17 17:11 ` Avihai Horon
2022-11-17 18:18 ` Alex Williamson
2022-11-20 9:39 ` Avihai Horon
2022-11-03 16:16 ` [PATCH v3 15/17] vfio: Alphabetize migration section of VFIO trace-events file Avihai Horon
2022-11-03 16:16 ` [PATCH v3 16/17] docs/devel: Align vfio-migration docs to VFIO migration v2 Avihai Horon
2022-11-03 16:16 ` [PATCH v3 17/17] vfio/migration: Query device data size in vfio_save_pending() Avihai Horon
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