On Thu, 16 Jan 2020 13:23:28 +0000 "Liu, Yi L" <yi.l.liu@xxxxxxxxx> wrote: > > From: Cornelia Huck [mailto:cohuck@xxxxxxxxxx] > > Sent: Wednesday, January 15, 2020 8:30 PM > > To: Liu, Yi L <yi.l.liu@xxxxxxxxx> > > Subject: Re: [PATCH v4 11/12] samples: add vfio-mdev-pci driver > > > > On Tue, 7 Jan 2020 20:01:48 +0800 > > Liu Yi L <yi.l.liu@xxxxxxxxx> wrote: > > > diff --git a/samples/Kconfig b/samples/Kconfig > > > index 9d236c3..50d207c 100644 > > > --- a/samples/Kconfig > > > +++ b/samples/Kconfig > > > @@ -190,5 +190,15 @@ config SAMPLE_INTEL_MEI > > > help > > > Build a sample program to work with mei device. > > > > > > +config SAMPLE_VFIO_MDEV_PCI > > > + tristate "Sample driver for wrapping PCI device as a mdev" > > > + select VFIO_PCI_COMMON > > > + select VFIO_PCI > > > > Why does this still need to select VFIO_PCI? Shouldn't all needed > > infrastructure rather be covered by VFIO_PCI_COMMON already? > > VFIO_PCI_COMMON is supposed to be the dependency of both VFIO_PCI and > SAMPLE_VFIO_MDEV_PCI. However, the source code of VFIO_PCI_COMMON are > under drivers/vfio/pci which is compiled per the configuration of VFIO_PCI. > Besides of letting SAMPLE_VFIO_MDEV_PCI select VFIO_PCI, I can also add > a line in drivers/vfio/Makefile to make the source code under drivers/vfio/pci > to be compiled when either VFIO_PCI or VFIO_PCI_COMMON are configed. But > I'm afraid it is a bit ugly. So I choose to let SAMPLE_VFIO_MDEV_PCI select > VFIO_PCI. If you have other idea, I would be pleased to > know it. :-) Shouldn't building drivers/vfio/pci/ for CONFIG_VFIO_PCI_COMMON already be enough (the Makefile changes look fine to me)? Or am I missing something obvious? > > > > > > + depends on VFIO_MDEV && VFIO_MDEV_DEVICE > > > > VFIO_MDEV_DEVICE already depends on VFIO_MDEV. But maybe also make this > > depend on PCI? > > > > > + help > > > + Sample driver for wrapping a PCI device as a mdev. Once bound to > > > + this driver, device passthru should through mdev path. > > > > "A PCI device bound to this driver will be assigned through the > > mediated device framework." > > > > ? > > Maybe I should have mentioned it as "A PCI device bound to this > sample driver should follow the passthru steps for mdevs as showed > in Documentation/driver-api/vfio-mediated-device.rst." > > Does it make more sense? Yes, it does :)
