Re: [PATCH] nodedev: transient mdev update on nodeDeviceCreateXML

On 6/23/23 5:43 AM, Boris Fiuczynski wrote: > Update the optional mdev attributes on the new created nodedev object as > they otherwise would not get set until the next mdevctl update cycle. > > Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=2143158 > Signed-off-by: Boris Fiuczynski <fiuczy(a)linux.ibm.com&gt; > --- >   src/node_device/node_device_driver.c | 18 ++++++++++++++++-- >   1 file changed, 16 insertions(+), 2 deletions(-) > > diff --git a/src/node_device/node_device_driver.c > b/src/node_device/node_device_driver.c > index a2d0600560..5134d246f3 100644 > --- a/src/node_device/node_device_driver.c > +++ b/src/node_device/node_device_driver.c > @@ -847,6 +847,9 @@ static virNodeDevicePtr >   nodeDeviceCreateXMLMdev(virConnectPtr conn, >                           virNodeDeviceDef *def) >   { > +    virNodeDeviceObj *obj; > +    virNodeDeviceDef *new_def; > +    virNodeDevicePtr device; >       g_autofree char *uuid = NULL; >       if (!def->parent) { > @@ -864,8 +867,19 @@ nodeDeviceCreateXMLMdev(virConnectPtr conn, >           def->caps->data.mdev.uuid = g_steal_pointer(&uuid); >       } > -    return nodeDeviceFindNewMediatedDevice(conn, > def->caps->data.mdev.uuid, > - > def->caps->data.mdev.parent_addr); > +    device = nodeDeviceFindNewMediatedDevice(conn, > def->caps->data.mdev.uuid, > + > def->caps->data.mdev.parent_addr); So, this function waits up to 60s for the given mediated device to show up in the list of devices known to the driver (which is stored in driver->devs and gets populated by handlers that respond to udev or mdevctl events)... > +    /* check on def for attributes and try update */ > +    if (def->caps->data.mdev.nattributes > 0) { > +        /* ignore failures as mdevctl updates will recover later */ > +        if (!(obj = nodeDeviceObjFindByName(device->name))) > +            return device; If the device was found and the device has mdev attributes, you then query the exact same list for a device with the name of the device you just found... > +        new_def = virNodeDeviceObjGetDef(obj); > +        nodeDeviceDefCopyFromMdevctl(new_def, def); If the device was found in the list (which it should be, because the nodeDeviceFindNewMediatedDevice() function had already found it in the list of devices), then we simply copy the user-supplied device definition into the definition we received from the nodedev driver's device list.

This is just papering over the issue. By copying the user-supplied definition into the system-queried definition, we're just assuming that the device was created properly with the requested attributes rather than verifying that it was created correctly.

The root issue seems to be that when a transient mediated device is created, our udev event handler runs and adds the device to the device list, but the mdevctl handler is never run to query additional mdev-related information about the device. mdevctl is only re-queried when the config files for defined devices are changed or when a new physical mdev parent device is added or removed.

Jonathon