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

From: Matthew Rosato <mjrosato@linux.ibm.com>
To: Cornelia Huck <cohuck@redhat.com>,
	Alex Williamson <alex.williamson@redhat.com>
Cc: kvm@vger.kernel.org, libvir-list@redhat.com,
	Tony Krowiak <akrowiak@linux.ibm.com>,
	Halil Pasic <pasic@linux.ibm.com>
Subject: Re: [PATCH RFC 0/1] mdevctl: further config for vfio-ap
Date: Thu, 6 Jun 2019 12:45:29 -0400	[thread overview]
Message-ID: <234ed452-45bd-e7ec-f1be-929e3b77d364@linux.ibm.com> (raw)
In-Reply-To: <20190606144417.1824-1-cohuck@redhat.com>

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.

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(-)
> 