> From: Cornelia Huck [mailto:cohuck@xxxxxxxxxx] > Sent: Friday, January 17, 2020 1:40 AM > To: Liu, Yi L <yi.l.liu@xxxxxxxxx> > Subject: Re: [PATCH v4 11/12] samples: add vfio-mdev-pci driver > > 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? The problem is in the drivers/vfio/Makefile. If CONFIG_VFIO_PCI is not selected then the pci/ directory is not compiled. Even CONFIG_VFIO_PCI=M, it will throw error if SAMPLE_VFIO_MDEV_PCI=y. So I let SAMPLE_VFIO_MDEV_PCI select CONFIG_VFIO_PCI all the same. I'm not sure if this is good. Or maybe there is better way to ensure pci/ is compiled. # SPDX-License-Identifier: GPL-2.0 vfio_virqfd-y := virqfd.o obj-$(CONFIG_VFIO) += vfio.o obj-$(CONFIG_VFIO_VIRQFD) += vfio_virqfd.o obj-$(CONFIG_VFIO_IOMMU_TYPE1) += vfio_iommu_type1.o obj-$(CONFIG_VFIO_IOMMU_SPAPR_TCE) += vfio_iommu_spapr_tce.o obj-$(CONFIG_VFIO_SPAPR_EEH) += vfio_spapr_eeh.o obj-$(CONFIG_VFIO_PCI) += pci/ obj-$(CONFIG_VFIO_PLATFORM) += platform/ obj-$(CONFIG_VFIO_MDEV) += mdev/ Thanks, Yi Liu
