Re: [PATCH V3 16/19] virtio-pci: introduce modern device module

[Michael S. Tsirkin]

On Wed, Feb 10, 2021 at 12:44:03PM +0800, Jason Wang wrote:
> 
> On 2021/2/9 下午10:20, Michael S. Tsirkin wrote:
> > On Mon, Jan 04, 2021 at 02:55:00PM +0800, Jason Wang wrote:
> > > Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
> > > ---
> > >   drivers/virtio/Kconfig                 |  10 +-
> > >   drivers/virtio/Makefile                |   1 +
> > >   drivers/virtio/virtio_pci_common.h     |  27 +-
> > >   drivers/virtio/virtio_pci_modern.c     | 617 -------------------------
> > >   drivers/virtio/virtio_pci_modern_dev.c | 599 ++++++++++++++++++++++++
> > >   include/linux/virtio_pci_modern.h      | 111 +++++
> > >   6 files changed, 721 insertions(+), 644 deletions(-)
> > >   create mode 100644 drivers/virtio/virtio_pci_modern_dev.c
> > >   create mode 100644 include/linux/virtio_pci_modern.h
> > > 
> > > diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
> > > index 7b41130d3f35..6b9b81f4b8c2 100644
> > > --- a/drivers/virtio/Kconfig
> > > +++ b/drivers/virtio/Kconfig
> > > @@ -12,6 +12,14 @@ config ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
> > >   	  This option is selected if the architecture may need to enforce
> > >   	  VIRTIO_F_ACCESS_PLATFORM
> > > +config VIRTIO_PCI_MODERN
> > > +	tristate "Modern Virtio PCI Device"
> > > +	depends on PCI
> > > +	help
> > > +	  Modern PCI device implementation. This module implements the
> > > +	  basic probe and control for devices which are based on modern
> > > +	  PCI device with possible vendor specific extensions.
> > > +
> > >   menuconfig VIRTIO_MENU
> > >   	bool "Virtio drivers"
> > >   	default y
> > > @@ -20,7 +28,7 @@ if VIRTIO_MENU
> > >   config VIRTIO_PCI
> > >   	tristate "PCI driver for virtio devices"
> > > -	depends on PCI
> > > +	depends on VIRTIO_PCI_MODERN
> > >   	select VIRTIO
> > >   	help
> > >   	  This driver provides support for virtio based paravirtual device
> > Looks like VIRTIO_PCI_MODERN is actually just a library that
> > virtio pci uses. Is that right?
> 
> 
> Right.
> 
> 
> > In that case just select it
> > automatically, let's not make users enable it manually.
> 
> 
> I've considered to do this but the problem is that the module depends on PCI
> so it can't be selected I think.

Drop the dependency, document that whoever selects it must depend on PCI.

> Thanks
> 
> 
> >