RE: [PATCH v2 02/13] vfio_pci: refine user config reference in vfio-pci module

[Liu, Yi L]

Hi Alex,

> From: Alex Williamson [mailto:alex.williamson@xxxxxxxxxx]
> Sent: Thursday, September 26, 2019 10:36 AM
> To: Liu, Yi L <yi.l.liu@xxxxxxxxx>
> Subject: Re: [PATCH v2 02/13] vfio_pci: refine user config reference in vfio-pci
> module
> 
> On Thu,  5 Sep 2019 15:59:19 +0800
> Liu Yi L <yi.l.liu@xxxxxxxxx> wrote:
> 
> > This patch adds three fields in struct vfio_pci_device to pass the user
> > configs of vfio-pci module to some functions which could be common in
> > future usage.
> >
> > Cc: Kevin Tian <kevin.tian@xxxxxxxxx>
> > Cc: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
> > Signed-off-by: Liu Yi L <yi.l.liu@xxxxxxxxx>
> > ---
> >  drivers/vfio/pci/vfio_pci.c         | 24 +++++++++++++++---------
> >  drivers/vfio/pci/vfio_pci_private.h |  9 +++++++--
> >  2 files changed, 22 insertions(+), 11 deletions(-)
> 
> A subtle behavioral difference here is that disable_idle_d3 and
> nointxmask are runtime modifiable parameters, if the value is changed
> in sysfs the device will adopt the new behavior on its next
> transition.  After this patch, each device operates in the mode defined
> at the time it was probed.  Should we maybe refresh the value at key
> points, like the user opening or releasing the device so that it tracks
> the module parameter?  I think we could defend not changing the
> behavior of a device while it's in use by a user.  Otherwise we might
> want to make the module parameter read-only to avoid the
> inconsistency.

Agreed. I think we can take such assumption that the changing is not
allowed during an open/release cycle. Let me add the updates in the
next version.

> 
> >
[...]
> > +	vfio_pci_fill_ids(&ids[0]);
> 
> Or just 'ids'.  Thanks,

yes, let me fix it.

> Alex
> 

Regards,
Yi Liu