RE: [PATCH 3/4] VFIO: pci: amend vfio-pci for explicit binding viasysfs only

From: Bhushan Bharat-R65777
Date: Thu Oct 24 2013 - 07:32:59 EST




> -----Original Message-----
> From: Kim Phillips [mailto:kim.phillips@xxxxxxxxxx]
> Sent: Saturday, October 12, 2013 4:47 AM
> To: Wood Scott-B07421
> Cc: Bhushan Bharat-R65777; Wood Scott-B07421; Yoder Stuart-B08248;
> christoffer.dall@xxxxxxxxxx; alex.williamson@xxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; a.motakis@xxxxxxxxxxxxxxxxxxxxxx; agraf@xxxxxxx; Sethi
> Varun-B16395; peter.maydell@xxxxxxxxxx; santosh.shukla@xxxxxxxxxx;
> kvm@xxxxxxxxxxxxxxx; gregkh@xxxxxxxxxxxxxxxxxxx
> Subject: Re: [PATCH 3/4] VFIO: pci: amend vfio-pci for explicit binding via
> sysfs only
>
> On Fri, 11 Oct 2013 15:43:40 -0500
> Scott Wood <scottwood@xxxxxxxxxxxxx> wrote:
>
> > On Fri, 2013-10-11 at 01:27 -0500, Kim Phillips wrote:
> > > Force the vfio-pci driver to only be bound explicitly via sysfs to avoid
> > > conflics with other drivers in the event of a hotplug.
> > >
> > > Signed-off-by: Kim Phillips <kim.phillips@xxxxxxxxxx>
> > > ---
> > > drivers/vfio/pci/vfio_pci.c | 3 +++
> > > 1 file changed, 3 insertions(+)
> > >
> > > diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
> > > index 6ab71b9..bdd7833 100644
> > > --- a/drivers/vfio/pci/vfio_pci.c
> > > +++ b/drivers/vfio/pci/vfio_pci.c
> > > @@ -901,6 +901,9 @@ static struct pci_driver vfio_pci_driver = {
> > > .probe = vfio_pci_probe,
> > > .remove = vfio_pci_remove,
> > > .err_handler = &vfio_err_handlers,
> > > + .driver = {
> > > + .sysfs_bind_only = true,
> > > + },
> > > };
> > >
> > > static void __exit vfio_pci_cleanup(void)
> >
> > You also need to add a PCI_ANY_ID match in order to be able to get rid
> > of the new_id usage.
>
> thanks - see below.
>
> Can someone with a PCI bus test this? Bharat?

Hello Kim,

I can test that we can get rid of new_id and use "bind" to bind the device to vfio_pci.

Other thing is generating hotplug, or reorder the driver registration by tweaking Makefile to test sysfs_bind_only way to bind is not yet tested.


Thanks
-Bharat

>
> Kim
>
> From a8d6c12f2ec763c2ac7fd384a3397c370cc1b932 Mon Sep 17 00:00:00 2001
> From: Kim Phillips <kim.phillips@xxxxxxxxxx>
> Date: Thu, 10 Oct 2013 22:16:34 -0500
> Subject: [PATCH 3/4 v2] VFIO: pci: amend vfio-pci for explicit binding via sysfs
> only
>
> Force the vfio-pci driver to only be bound explicitly via sysfs to avoid
> conflics with other drivers in the event of a hotplug. Also replace
> the only dynamic ids assignment with a table with a single PCI_ANY_ID
> entry since writing the sysfs bind file without having to specify ids
> via the new_id file first should no longer be necessary.
>
> Signed-off-by: Kim Phillips <kim.phillips@xxxxxxxxxx>
> ---
> drivers/vfio/pci/vfio_pci.c | 12 +++++++++++-
> 1 file changed, 11 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
> index 6ab71b9..c5b434f 100644
> --- a/drivers/vfio/pci/vfio_pci.c
> +++ b/drivers/vfio/pci/vfio_pci.c
> @@ -895,12 +895,22 @@ static struct pci_error_handlers vfio_err_handlers = {
> .error_detected = vfio_pci_aer_err_detected,
> };
>
> +static DEFINE_PCI_DEVICE_TABLE(vfio_pci_id_table) = {
> + { PCI_DEVICE(PCI_ANY_ID, PCI_ANY_ID) },
> + { 0 }
> +};
> +
> +MODULE_DEVICE_TABLE(pci, vfio_pci_id_table);
> +
> static struct pci_driver vfio_pci_driver = {
> .name = "vfio-pci",
> - .id_table = NULL, /* only dynamic ids */
> + .id_table = vfio_pci_id_table, /* no dynamic ids */
> .probe = vfio_pci_probe,
> .remove = vfio_pci_remove,
> .err_handler = &vfio_err_handlers,
> + .driver = {
> + .sysfs_bind_only = true, /* bind only via sysfs */
> + },
> };
>
> static void __exit vfio_pci_cleanup(void)
> --
> 1.8.4


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