From: Alex Williamson <alex.williamson@redhat.com>
To: Yan Zhao <yan.y.zhao@intel.com>
Cc: "Parav Pandit" <parav@nvidia.com>,
"Cornelia Huck" <cohuck@redhat.com>,
"Daniel P. Berrangé" <berrange@redhat.com>,
"Jason Wang" <jasowang@redhat.com>,
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<openstack-discuss@lists.openstack.org>,
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"devel@ovirt.org" <devel@ovirt.org>
Subject: Re: device compatibility interface for live migration with assigned devices
Date: Wed, 19 Aug 2020 21:13:45 -0600 [thread overview]
Message-ID: <20200819211345.0d9daf03@x1.home> (raw)
In-Reply-To: <20200820001810.GD21172@joy-OptiPlex-7040>
On Thu, 20 Aug 2020 08:18:10 +0800
Yan Zhao <yan.y.zhao@intel.com> wrote:
> On Wed, Aug 19, 2020 at 11:50:21AM -0600, Alex Williamson wrote:
> <...>
> > > > > > What I care about is that we have a *standard* userspace API for
> > > > > > performing device compatibility checking / state migration, for use by
> > > > > > QEMU/libvirt/ OpenStack, such that we can write code without countless
> > > > > > vendor specific code paths.
> > > > > >
> > > > > > If there is vendor specific stuff on the side, that's fine as we can
> > > > > > ignore that, but the core functionality for device compat / migration
> > > > > > needs to be standardized.
> > > > >
> > > > > To summarize:
> > > > > - choose one of sysfs or devlink
> > > > > - have a common interface, with a standardized way to add
> > > > > vendor-specific attributes
> > > > > ?
> > > >
> > > > Please refer to my previous email which has more example and details.
> > > hi Parav,
> > > the example is based on a new vdpa tool running over netlink, not based
> > > on devlink, right?
> > > For vfio migration compatibility, we have to deal with both mdev and physical
> > > pci devices, I don't think it's a good idea to write a new tool for it, given
> > > we are able to retrieve the same info from sysfs and there's already an
> > > mdevctl from Alex (https://github.com/mdevctl/mdevctl).
> > >
> > > hi All,
> > > could we decide that sysfs is the interface that every VFIO vendor driver
> > > needs to provide in order to support vfio live migration, otherwise the
> > > userspace management tool would not list the device into the compatible
> > > list?
> > >
> > > if that's true, let's move to the standardizing of the sysfs interface.
> > > (1) content
> > > common part: (must)
> > > - software_version: (in major.minor.bugfix scheme)
> > > - device_api: vfio-pci or vfio-ccw ...
> > > - type: mdev type for mdev device or
> > > a signature for physical device which is a counterpart for
> > > mdev type.
> > >
> > > device api specific part: (must)
> > > - pci id: pci id of mdev parent device or pci id of physical pci
> > > device (device_api is vfio-pci)
> >
> > As noted previously, the parent PCI ID should not matter for an mdev
> > device, if a vendor has a dependency on matching the parent device PCI
> > ID, that's a vendor specific restriction. An mdev device can also
> > expose a vfio-pci device API without the parent device being PCI. For
> > a physical PCI device, shouldn't the PCI ID be encompassed in the
> > signature? Thanks,
> >
> you are right. I need to put the PCI ID as a vendor specific field.
> I didn't do that because I wanted all fields in vendor specific to be
> configurable by management tools, so they can configure the target device
> according to the value of a vendor specific field even they don't know
> the meaning of the field.
> But maybe they can just ignore the field when they can't find a matching
> writable field to configure the target.
If fields can be ignored, what's the point of reporting them? Seems
it's no longer a requirement. Thanks,
Alex
> > > - subchannel_type (device_api is vfio-ccw)
> > >
> > > vendor driver specific part: (optional)
> > > - aggregator
> > > - chpid_type
> > > - remote_url
> > >
> > > NOTE: vendors are free to add attributes in this part with a
> > > restriction that this attribute is able to be configured with the same
> > > name in sysfs too. e.g.
> > > for aggregator, there must be a sysfs attribute in device node
> > > /sys/devices/pci0000:00/0000:00:02.0/882cc4da-dede-11e7-9180-078a62063ab1/intel_vgpu/aggregator,
> > > so that the userspace tool is able to configure the target device
> > > according to source device's aggregator attribute.
> > >
> > >
> > > (2) where and structure
> > > proposal 1:
> > > |- [path to device]
> > > |--- migration
> > > | |--- self
> > > | | |-software_version
> > > | | |-device_api
> > > | | |-type
> > > | | |-[pci_id or subchannel_type]
> > > | | |-<aggregator or chpid_type>
> > > | |--- compatible
> > > | | |-software_version
> > > | | |-device_api
> > > | | |-type
> > > | | |-[pci_id or subchannel_type]
> > > | | |-<aggregator or chpid_type>
> > > multiple compatible is allowed.
> > > attributes should be ASCII text files, preferably with only one value
> > > per file.
> > >
> > >
> > > proposal 2: use bin_attribute.
> > > |- [path to device]
> > > |--- migration
> > > | |--- self
> > > | |--- compatible
> > >
> > > so we can continue use multiline format. e.g.
> > > cat compatible
> > > software_version=0.1.0
> > > device_api=vfio_pci
> > > type=i915-GVTg_V5_{val1:int:1,2,4,8}
> > > pci_id=80865963
> > > aggregator={val1}/2
> > >
> > > Thanks
> > > Yan
> > >
> >
>
next prev parent reply other threads:[~2020-08-20 3:14 UTC|newest]
Thread overview: 114+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-13 23:29 device compatibility interface for live migration with assigned devices Yan Zhao
2020-07-14 10:21 ` Daniel P. Berrangé
2020-07-14 12:33 ` Sean Mooney
[not found] ` <20200714110148.0471c03c@x1.home>
[not found] ` <eb705c72cdc8b6b8959b6ebaeeac6069a718d524.camel@redhat.com>
2020-07-14 21:15 ` Sean Mooney
2020-07-14 16:16 ` Alex Williamson
2020-07-14 16:47 ` Daniel P. Berrangé
2020-07-14 20:47 ` Alex Williamson
2020-07-15 9:16 ` Daniel P. Berrangé
2020-07-14 17:19 ` Dr. David Alan Gilbert
2020-07-14 20:59 ` Alex Williamson
2020-07-15 8:20 ` Yan Zhao
2020-07-15 8:49 ` Feng, Shaohe
2020-07-17 14:59 ` Alex Williamson
2020-07-17 18:03 ` Dr. David Alan Gilbert
2020-07-17 18:30 ` Alex Williamson
2020-07-15 8:23 ` Dr. David Alan Gilbert
[not found] ` <CAH7mGatPWsczh_rbVhx4a+psJXvkZgKou3r5HrEQTqE7SqZkKA@mail.gmail.com>
2020-07-17 15:18 ` Alex Williamson
2020-07-16 4:16 ` Jason Wang
2020-07-16 8:32 ` Yan Zhao
2020-07-16 9:30 ` Jason Wang
2020-07-17 16:12 ` Alex Williamson
2020-07-20 3:41 ` Jason Wang
2020-07-20 10:39 ` Sean Mooney
2020-07-21 2:11 ` Jason Wang
2020-07-21 0:51 ` Yan Zhao
2020-07-27 7:24 ` Yan Zhao
2020-07-27 22:23 ` Alex Williamson
2020-07-29 8:05 ` Yan Zhao
2020-07-29 11:28 ` Sean Mooney
2020-07-29 19:12 ` Alex Williamson
2020-07-30 3:41 ` Yan Zhao
2020-07-30 13:24 ` Sean Mooney
2020-07-30 17:29 ` Alex Williamson
2020-08-04 8:37 ` Yan Zhao
2020-08-05 9:44 ` Dr. David Alan Gilbert
2020-07-30 1:56 ` Yan Zhao
2020-07-30 13:14 ` Sean Mooney
2020-08-04 16:35 ` Cornelia Huck
2020-08-05 2:22 ` Jason Wang
2020-08-05 2:16 ` Yan Zhao
2020-08-05 2:41 ` Jason Wang
2020-08-05 7:56 ` Jiri Pirko
2020-08-05 8:02 ` Jason Wang
2020-08-05 9:33 ` Yan Zhao
2020-08-05 10:53 ` Jiri Pirko
2020-08-05 11:35 ` Sean Mooney
2020-08-07 11:59 ` Cornelia Huck
2020-08-13 15:33 ` Cornelia Huck
2020-08-13 19:02 ` Eric Farman
2020-08-17 6:38 ` Cornelia Huck
2020-08-10 7:46 ` Yan Zhao
2020-08-13 4:24 ` Jason Wang
2020-08-14 5:16 ` Yan Zhao
2020-08-14 12:30 ` Sean Mooney
2020-08-17 1:52 ` Yan Zhao
2020-08-18 3:24 ` Jason Wang
2020-08-18 8:55 ` Daniel P. Berrangé
2020-08-18 9:06 ` Cornelia Huck
2020-08-18 9:24 ` Daniel P. Berrangé
2020-08-18 9:38 ` Cornelia Huck
[not found] ` <3a073222-dcfe-c02d-198b-29f6a507b2e1@redhat.com>
2020-08-18 9:16 ` Daniel P. Berrangé
2020-08-18 9:36 ` Cornelia Huck
2020-08-18 9:39 ` Parav Pandit
2020-08-19 3:30 ` Yan Zhao
2020-08-19 5:58 ` Parav Pandit
2020-08-19 9:41 ` Jason Wang
2020-08-19 6:57 ` [ovirt-devel] " Jason Wang
2020-08-19 6:59 ` Yan Zhao
2020-08-19 7:39 ` Jason Wang
2020-08-19 8:13 ` Yan Zhao
2020-08-19 9:28 ` Jason Wang
2020-08-20 12:27 ` Cornelia Huck
2020-08-21 3:14 ` Jason Wang
2020-08-21 14:52 ` Cornelia Huck
2020-08-31 3:07 ` Jason Wang
2020-08-19 17:50 ` Alex Williamson
2020-08-20 0:18 ` Yan Zhao
2020-08-20 3:13 ` Alex Williamson [this message]
2020-08-20 3:09 ` Yan Zhao
2020-08-19 2:54 ` Jason Wang
2020-08-20 0:39 ` Yan Zhao
2020-08-20 1:29 ` Sean Mooney
2020-08-20 4:01 ` Yan Zhao
2020-08-20 5:16 ` Sean Mooney
2020-08-20 6:27 ` Yan Zhao
2020-08-20 13:24 ` Sean Mooney
2020-08-26 8:54 ` Yan Zhao
2020-08-20 3:22 ` Alex Williamson
2020-08-20 3:16 ` Yan Zhao
2020-08-25 14:39 ` Cornelia Huck
2020-08-26 6:41 ` Yan Zhao
2020-08-28 13:47 ` Cornelia Huck
2020-08-28 14:04 ` Sean Mooney
2020-08-31 4:43 ` Yan Zhao
2020-09-08 14:41 ` Cornelia Huck
2020-09-09 2:13 ` Yan Zhao
2020-09-10 12:38 ` Cornelia Huck
2020-09-10 12:50 ` Sean Mooney
2020-09-10 18:02 ` Alex Williamson
2020-09-11 0:56 ` Yan Zhao
2020-09-11 10:08 ` Cornelia Huck
2020-09-11 10:18 ` Tian, Kevin
2020-09-11 16:51 ` Alex Williamson
2020-09-14 13:48 ` Zeng, Xin
2020-09-14 14:44 ` Alex Williamson
2020-09-09 5:37 ` Yan Zhao
2020-08-31 2:23 ` Yan Zhao
2020-08-19 2:38 ` Jason Wang
2020-08-18 9:32 ` Parav Pandit
2020-08-19 2:45 ` Jason Wang
2020-08-19 5:26 ` Parav Pandit
2020-08-19 6:48 ` Jason Wang
2020-08-19 6:53 ` Parav Pandit
2020-07-29 19:05 ` Dr. David Alan Gilbert
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