On 2019/12/5 下午2:06, Zhenyu Wang wrote:
On 2019.12.04 17:36:12 +0000, Parav Pandit wrote:
+ Jiri + Netdev since you mentioned netdev queue.
+ Jason Wang and Michael as we had similar discussion in vdpa discussion thread.
From: Zhenyu Wang <zhenyuw@xxxxxxxxxxxxxxx>
Sent: Friday, November 8, 2019 2:19 AM
To: Parav Pandit <parav@xxxxxxxxxxxx>
My apologies to reply late.
Something bad with my email client, due to which I found this patch under spam folder today.
More comments below.
On 2019.11.07 20:37:49 +0000, Parav Pandit wrote:
Hi,
-----Original Message-----
From: kvm-owner@xxxxxxxxxxxxxxx <kvm-owner@xxxxxxxxxxxxxxx> On
Behalf Of Zhenyu Wang
Sent: Thursday, October 24, 2019 12:08 AM
To: kvm@xxxxxxxxxxxxxxx
Cc: alex.williamson@xxxxxxxxxx; kwankhede@xxxxxxxxxx;
kevin.tian@xxxxxxxxx; cohuck@xxxxxxxxxx
Subject: [PATCH 0/6] VFIO mdev aggregated resources handling
Hi,
This is a refresh for previous send of this series. I got impression
that some SIOV drivers would still deploy their own create and
config method so stopped effort on this. But seems this would still
be useful for some other SIOV driver which may simply want
capability to aggregate resources. So here's refreshed series.
Current mdev device create interface depends on fixed mdev type,
which get uuid from user to create instance of mdev device. If user
wants to use customized number of resource for mdev device, then
only can create new
Can you please give an example of 'resource'?
When I grep [1], [2] and [3], I couldn't find anything related to ' aggregate'.
The resource is vendor device specific, in SIOV spec there's ADI (Assignable
Device Interface) definition which could be e.g queue for net device, context
for gpu, etc. I just named this interface as 'aggregate'
for aggregation purpose, it's not used in spec doc.
Some 'unknown/undefined' vendor specific resource just doesn't work.
Orchestration tool doesn't know which resource and what/how to configure for which vendor.
It has to be well defined.
You can also find such discussion in recent lgpu DRM cgroup patches series v4.
Exposing networking resource configuration in non-net namespace aware mdev sysfs at PCI device level is no-go.
Adding per file NET_ADMIN or other checks is not the approach we follow in kernel.
devlink has been a subsystem though under net, that has very rich interface for syscaller, device health, resource management and many more.
Even though it is used by net driver today, its written for generic device management at bus/device level.
Yuval has posted patches to manage PCI sub-devices [1] and updated version will be posted soon which addresses comments.
For any device slice resource management of mdev, sub-function etc, we should be using single kernel interface as devlink [2], [3].
[1] https://lore.kernel.org/netdev/1573229926-30040-1-git-send-email-yuvalav@xxxxxxxxxxxx/
[2] http://man7.org/linux/man-pages/man8/devlink-dev.8.html
[3] http://man7.org/linux/man-pages/man8/devlink-resource.8.html
Most modern device configuration that I am aware of is usually done via well defined ioctl() of the subsystem (vhost, virtio, vfio, rdma, nvme and more) or via netlink commands (net, devlink, rdma and more) not via sysfs.
Current vfio/mdev configuration is via documented sysfs ABI instead of
other ways. So this adhere to that way to introduce more configurable
method on mdev device for standard, it's optional and not actually
vendor specific e.g vfio-ap.
I'm not sure how many devices support devlink now, or if really make
sense to utilize devlink for other devices except net, or if really make
sense to take mdev resource configuration from there...
It may make sense to allow other types of API to manage mdev other than
sysfs. But I'm not sure whether or not it will be a challenge for
orchestration.
Thanks
mdev type for that which may not be flexible. This requirement comes
not only from to be able to allocate flexible resources for KVMGT,
but also from Intel scalable IO virtualization which would use
vfio/mdev to be able to allocate arbitrary resources on mdev instance.
More info on [1] [2] [3].
To allow to create user defined resources for mdev, it trys to
extend mdev create interface by adding new "aggregate=xxx" parameter
following UUID, for target mdev type if aggregation is supported, it
can create new mdev device which contains resources combined by
number of instances, e.g
echo "<uuid>,aggregate=10" > create
VM manager e.g libvirt can check mdev type with "aggregation"
attribute which can support this setting. If no "aggregation"
attribute found for mdev type, previous behavior is still kept for
one instance allocation. And new sysfs attribute
"aggregated_instances" is created for each mdev device to show allocated
number.
References:
[1]
https://software.intel.com/en-us/download/intel-virtualization-techn
ology- for-directed-io-architecture-specification
[2]
https://software.intel.com/en-us/download/intel-scalable-io-virtuali
zation-
technical-specification
[3] https://schd.ws/hosted_files/lc32018/00/LC3-SIOV-final.pdf
Zhenyu Wang (6):
vfio/mdev: Add new "aggregate" parameter for mdev create
vfio/mdev: Add "aggregation" attribute for supported mdev type
vfio/mdev: Add "aggregated_instances" attribute for supported mdev
device
Documentation/driver-api/vfio-mediated-device.rst: Update for
vfio/mdev aggregation support
Documentation/ABI/testing/sysfs-bus-vfio-mdev: Update for vfio/mdev
aggregation support
drm/i915/gvt: Add new type with aggregation support
Documentation/ABI/testing/sysfs-bus-vfio-mdev | 24 ++++++
.../driver-api/vfio-mediated-device.rst | 23 ++++++
drivers/gpu/drm/i915/gvt/gvt.c | 4 +-
drivers/gpu/drm/i915/gvt/gvt.h | 11 ++-
drivers/gpu/drm/i915/gvt/kvmgt.c | 53 ++++++++++++-
drivers/gpu/drm/i915/gvt/vgpu.c | 56 ++++++++++++-
drivers/vfio/mdev/mdev_core.c | 36 ++++++++-
drivers/vfio/mdev/mdev_private.h | 6 +-
drivers/vfio/mdev/mdev_sysfs.c | 79 ++++++++++++++++++-
include/linux/mdev.h | 19 +++++
10 files changed, 294 insertions(+), 17 deletions(-)
--
2.24.0.rc0
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