From a67efff28832a597f46a0097916833937aa3983e Mon Sep 17 00:00:00 2001 From: Oleksandr Andrushchenko Date: Thu, 28 Oct 2021 17:36:20 +0300 Subject: xen-pciback: allow compiling on other archs than x86 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 Signed-off-by: Anastasiia Lukianenko Reviewed-by: Stefano Stabellini Reviewed-by: Juergen Gross Link: https://lore.kernel.org/r/20211028143620.144936-1-andr2000@gmail.com Signed-off-by: Boris Ostrovsky --- drivers/xen/Kconfig | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) (limited to 'drivers/xen/Kconfig') diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig index 1b2c3aca6887..a1b11c62da9e 100644 --- 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 + 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 -- cgit v1.2.3