[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [PATCH] xen-pciback: allow compiling on other archs than x86
Hi Oleksandr, On Thu, Oct 28, 2021 at 8:15 AM Oleksandr Andrushchenko <andr2000@xxxxxxxxx> wrote: > From: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx> > > Xen-pciback driver was designed to be built for x86 only. But it > can also be used by other architectures, e.g. Arm. > > Currently PCI backend implements multiple functionalities at a time, > such as: > 1. It is used as a database for assignable PCI devices, e.g. xl > pci-assignable-{add|remove|list} manipulates that list. So, whenever > the toolstack needs to know which PCI devices can be passed through > it reads that from the relevant sysfs entries of the pciback. > 2. It is used to hold the unbound PCI devices list, e.g. when passing > through a PCI device it needs to be unbound from the relevant device > driver and bound to pciback (strictly speaking it is not required > that the device is bound to pciback, but pciback is again used as a > database of the passed through PCI devices, so we can re-bind the > devices back to their original drivers when guest domain shuts down) > 3. Device reset for the devices being passed through > 4. Para-virtualised use-cases support > > The para-virtualised part of the driver is not always needed as some > architectures, e.g. Arm or x86 PVH Dom0, are not using backend-frontend > model for PCI device passthrough. > > For such use-cases make the very first step in splitting the > xen-pciback driver into two parts: Xen PCI stub and PCI PV backend > drivers. > > For that add new configuration options CONFIG_XEN_PCI_STUB and > CONFIG_XEN_PCIDEV_STUB, so the driver can be limited in its > functionality, e.g. no support for para-virtualised scenario. > x86 platform will continue using CONFIG_XEN_PCIDEV_BACKEND for the > fully featured backend driver. > > Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx> > Signed-off-by: Anastasiia Lukianenko <anastasiia_lukianenko@xxxxxxxx> > Reviewed-by: Stefano Stabellini <sstabellini@xxxxxxxxxx> > Reviewed-by: Juergen Gross <jgross@xxxxxxxx> Thanks for your patch, which is now commit a67efff28832a597 ("xen-pciback: allow compiling on other archs than x86") in v5.16-rc1. > --- a/drivers/xen/Kconfig > +++ b/drivers/xen/Kconfig > @@ -181,10 +181,34 @@ config SWIOTLB_XEN > select DMA_OPS > select SWIOTLB > > +config XEN_PCI_STUB > + bool > + > +config XEN_PCIDEV_STUB > + tristate "Xen PCI-device stub driver" > + depends on PCI && !X86 && XEN > + depends on XEN_BACKEND > + select XEN_PCI_STUB > + default m Please note that this means "default y" if CONFIG_MODULES=n. Perhaps this should be "default m if MODULES" instead? > + help > + The PCI device stub driver provides limited version of the PCI > + device backend driver without para-virtualized support for guests. > + If you select this to be a module, you will need to make sure no > + other driver has bound to the device(s) you want to make visible to > + other guests. > + > + The "hide" parameter (only applicable if backend driver is compiled > + into the kernel) allows you to bind the PCI devices to this module > + from the default device drivers. The argument is the list of PCI > BDFs: > + xen-pciback.hide=(03:00.0)(04:00.0) > + > + If in doubt, say m. > + > config XEN_PCIDEV_BACKEND > tristate "Xen PCI-device backend driver" > depends on PCI && X86 && XEN > depends on XEN_BACKEND > + select XEN_PCI_STUB > default m > help > The PCI device backend driver allows the kernel to export arbitrary Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
|
![]() |
Lists.xenproject.org is hosted with RackSpace, monitoring our |