Re: [PATCH RFC 0/1] mdevctl: further config for vfio-ap

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 6/13/19 9:54 AM, Cornelia Huck wrote:
On Fri, 7 Jun 2019 14:30:48 -0400
Tony Krowiak <akrowiak@xxxxxxxxxxxxx> wrote:

On 6/7/19 10:56 AM, Cornelia Huck wrote:
On Thu, 6 Jun 2019 12:45:29 -0400
Matthew Rosato <mjrosato@xxxxxxxxxxxxx> wrote:
On 6/6/19 10:44 AM, Cornelia Huck wrote:
This patch adds a very rough implementation of additional config data
for mdev devices. The idea is to make it possible to specify some
type-specific key=value pairs in the config file for an mdev device.
If a device is started automatically, the device is stopped and restarted
after applying the config.

The code has still some problems, like not doing a lot of error handling
and being ugly in general; but most importantly, I can't really test it,
as I don't have the needed hardware. Feedback welcome; would be good to
know if the direction is sensible in general.

Hi Connie,

This is very similar to what I was looking to do in zdev (config via
key=value pairs), so I like your general approach.

I pulled your code and took it for a spin on an LPAR with access to
crypto cards:

# mdevctl create-mdev `uuidgen` matrix vfio_ap-passthrough
# mdevctl set-additional-config <uuid> ap_adapters=0x4,0x5
# mdevctl set-additional-config <uuid> ap_domains=0x36
# mdevctl set-additional-config <uuid> ap_control_domains=0x37

Assuming all valid inputs, this successfully creates the appropriate
mdev and what looks to be a valid mdevctl.d entry.  A subsequent reboot
successfully brings the same vfio_ap-passthrough device up again.

Cool, thanks for checking!

I also confirmed this. I realize this is a very early proof of concept,
if you will, but error handling could be an interesting endeavor in
the case of vfio_ap given the layers of configuration involved;

I agree; that's why I mostly ignored it for now :)

for
example:

* The necessity for the vfio_ap module to be installed
* The necessity that the /sys/bus/ap/apmask and /sys/bus/ap/aqmask must
    be appropriately configured

What do you think about outsourcing that configuration to some
s390-specific tool (probably something in s390-tools)? While we can
(and should) rely on driverctl for vfio-ccw, this does not look like
something that can be easily served by some generic tooling.

I wasn't suggesting configuration of the AP bus masks etc. should be
part of this tool, I was merely pointing out that errors encountered
when creating and configuring an mdev can be related to items higher in
the stack, thus making it difficult to isolate the real problem. There
are plans in place for an s390 tool that I assume will sit on top of
mdevctl should it move forward.




Matt

Also available at

https://github.com/cohuck/mdevctl conf-data

Cornelia Huck (1):
    allow to specify additional config data

   mdevctl.libexec | 25 ++++++++++++++++++++++
   mdevctl.sbin    | 56 ++++++++++++++++++++++++++++++++++++++++++++++++-
   2 files changed, 80 insertions(+), 1 deletion(-)






[Index of Archives]     [KVM ARM]     [KVM ia64]     [KVM ppc]     [Virtualization Tools]     [Spice Development]     [Libvirt]     [Libvirt Users]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite Questions]     [Linux Kernel]     [Linux SCSI]     [XFree86]

  Powered by Linux