From a8ccf8a666639ca9184e8b23d515d9fbe722a27d Mon Sep 17 00:00:00 2001 From: Alexander Duyck Date: Tue, 24 Apr 2018 16:47:16 -0500 Subject: PCI/IOV: Add pci-pf-stub driver for PFs that only enable VFs Some SR-IOV PF devices provide no functionality other than acting as a means of enabling VFs. For these devices, we want to enable the VFs and assign them to guest virtual machines, but there's no need to have a driver for the PF itself. Add a new pci-pf-stub driver to claim those PF devices and provide the generic VF enable functionality. An administrator can use the sysfs "sriov_numvfs" file to enable VFs, then assign them to guests. For now I only have one example ID provided by Amazon in terms of devices that require this functionality. The general idea is that in the future we will see other devices added as vendors come up with devices where the PF is more or less just a lightweight shim used to allocate VFs. Signed-off-by: Alexander Duyck [bhelgaas: changelog] Signed-off-by: Bjorn Helgaas Reviewed-by: Greg Rose Reviewed-by: Christoph Hellwig --- drivers/pci/Kconfig | 12 +++++++++++ drivers/pci/Makefile | 1 + drivers/pci/pci-pf-stub.c | 54 +++++++++++++++++++++++++++++++++++++++++++++++ include/linux/pci_ids.h | 2 ++ 4 files changed, 69 insertions(+) create mode 100644 drivers/pci/pci-pf-stub.c diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig index 34b56a8..cdef2a2 100644 --- a/drivers/pci/Kconfig +++ b/drivers/pci/Kconfig @@ -71,6 +71,18 @@ config PCI_STUB When in doubt, say N. +config PCI_PF_STUB + tristate "PCI PF Stub driver" + depends on PCI + depends on PCI_IOV + help + Say Y or M here if you want to enable support for devices that + require SR-IOV support, while at the same time the PF itself is + not providing any actual services on the host itself such as + storage or networking. + + When in doubt, say N. + config XEN_PCIDEV_FRONTEND tristate "Xen PCI Frontend" depends on PCI && X86 && XEN diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile index 952addc..84c9eef 100644 --- a/drivers/pci/Makefile +++ b/drivers/pci/Makefile @@ -24,6 +24,7 @@ obj-$(CONFIG_PCI_LABEL) += pci-label.o obj-$(CONFIG_X86_INTEL_MID) += pci-mid.o obj-$(CONFIG_PCI_SYSCALL) += syscall.o obj-$(CONFIG_PCI_STUB) += pci-stub.o +obj-$(CONFIG_PCI_PF_STUB) += pci-pf-stub.o obj-$(CONFIG_PCI_ECAM) += ecam.o obj-$(CONFIG_XEN_PCIDEV_FRONTEND) += xen-pcifront.o diff --git a/drivers/pci/pci-pf-stub.c b/drivers/pci/pci-pf-stub.c new file mode 100644 index 0000000..9795649 --- /dev/null +++ b/drivers/pci/pci-pf-stub.c @@ -0,0 +1,54 @@ +// SPDX-License-Identifier: GPL-2.0 +/* pci-pf-stub - simple stub driver for PCI SR-IOV PF device + * + * This driver is meant to act as a "whitelist" for devices that provde + * SR-IOV functionality while at the same time not actually needing a + * driver of their own. + */ + +#include +#include + +/** + * pci_pf_stub_whitelist - White list of devices to bind pci-pf-stub onto + * + * This table provides the list of IDs this driver is supposed to bind + * onto. You could think of this as a list of "quirked" devices where we + * are adding support for SR-IOV here since there are no other drivers + * that they would be running under. + */ +static const struct pci_device_id pci_pf_stub_whitelist[] = { + { PCI_VDEVICE(AMAZON, 0x0053) }, + /* required last entry */ + { 0 } +}; +MODULE_DEVICE_TABLE(pci, pci_pf_stub_whitelist); + +static int pci_pf_stub_probe(struct pci_dev *dev, + const struct pci_device_id *id) +{ + pci_info(dev, "claimed by pci-pf-stub\n"); + return 0; +} + +static struct pci_driver pf_stub_driver = { + .name = "pci-pf-stub", + .id_table = pci_pf_stub_whitelist, + .probe = pci_pf_stub_probe, + .sriov_configure = pci_sriov_configure_simple, +}; + +static int __init pci_pf_stub_init(void) +{ + return pci_register_driver(&pf_stub_driver); +} + +static void __exit pci_pf_stub_exit(void) +{ + pci_unregister_driver(&pf_stub_driver); +} + +module_init(pci_pf_stub_init); +module_exit(pci_pf_stub_exit); + +MODULE_LICENSE("GPL"); diff --git a/include/linux/pci_ids.h b/include/linux/pci_ids.h index cc608fc5..411c122 100644 --- a/include/linux/pci_ids.h +++ b/include/linux/pci_ids.h @@ -2552,6 +2552,8 @@ #define PCI_VENDOR_ID_CIRCUITCO 0x1cc8 #define PCI_SUBSYSTEM_ID_CIRCUITCO_MINNOWBOARD 0x0001 +#define PCI_VENDOR_ID_AMAZON 0x1d0f + #define PCI_VENDOR_ID_TEKRAM 0x1de1 #define PCI_DEVICE_ID_TEKRAM_DC290 0xdc29 -- cgit v1.1