On Wed, Aug 14, 2019 at 12:03 AM Jonathon Jongsma <jjongsma@redhat.com> wrote:
When a host is rebooted, mediated devices disappear from sysfs. mdevctl (https://github.com/mdevctl/mdevctl) is a utility for managing and persisting these devices. It maintains a registry of mediated devices and can start and stop them by UUID.
when libvirt attempts to create a new mediated device object, we currently fail if the path does not exist in sysfs. This patch tries a little bit harder by using mdevctl to attempt to activate the device. The approach is fairly naive -- it just calls 'mdevctl start -u $UUID' without checking whether this UUID is registered with mdevctl or not.
See https://bugzilla.redhat.com/show_bug.cgi?id=1699274
Signed-off-by: Jonathon Jongsma <jjongsma@redhat.com> --- NOTES: - an argument could be made that we should simply do nothing here. mdevctl does have support for automatically activating the mediated device when the parent device becomes available (via udev). So if the administrator set up the mdev to start automatically, this patch should not even be necessary. That said, I think this patch could still be useful. - As I said above, the approach is pretty naive. I could have checked whether the device was defined in mdevctl's registry and given a different error message ("try registering this device with mdevctl") in that scenario. But I chose to keep it simple.
So, I've noticed that mdevctl is not on Fedora yet, at least according to: https://bugzilla.redhat.com/show_bug.cgi?id=1728381 In any case, would you mind to also update the spec file and add something like: `Recommends: mdevctl`? Recommends is a weak dependency. It shouldn't force mdevctl to be installed, but suggests it to be installed. Best Regards, -- Fabiano Fidêncio