From 2597ba763fc44e247e462177abfe92d95bc5e6d5 Mon Sep 17 00:00:00 2001 From: Donald Dutile Date: Tue, 27 Nov 2012 22:31:37 -0500 Subject: PCI: SRIOV control and status via sysfs (documentation) Add documentation of new sysfs files and new pci_driver SRIOV configuration interface. [bhelgaas: changelog] Signed-off: Donald Dutile Signed-off-by: Bjorn Helgaas --- Documentation/ABI/testing/sysfs-bus-pci | 34 +++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) (limited to 'Documentation/ABI') diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci index dff1f48d252d..1ce5ae329c04 100644 --- a/Documentation/ABI/testing/sysfs-bus-pci +++ b/Documentation/ABI/testing/sysfs-bus-pci @@ -222,3 +222,37 @@ Description: satisfied too. Reading this attribute will show the current value of d3cold_allowed bit. Writing this attribute will set the value of d3cold_allowed bit. + +What: /sys/bus/pci/devices/.../sriov_totalvfs +Date: November 2012 +Contact: Donald Dutile +Description: + This file appears when a physical PCIe device supports SR-IOV. + Userspace applications can read this file to determine the + maximum number of Virtual Functions (VFs) a PCIe physical + function (PF) can support. Typically, this is the value reported + in the PF's SR-IOV extended capability structure's TotalVFs + element. Drivers have the ability at probe time to reduce the + value read from this file via the pci_sriov_set_totalvfs() + function. + +What: /sys/bus/pci/devices/.../sriov_numvfs +Date: November 2012 +Contact: Donald Dutile +Description: + This file appears when a physical PCIe device supports SR-IOV. + Userspace applications can read and write to this file to + determine and control the enablement or disablement of Virtual + Functions (VFs) on the physical function (PF). A read of this + file will return the number of VFs that are enabled on this PF. + A number written to this file will enable the specified + number of VFs. A userspace application would typically read the + file and check that the value is zero, and then write the number + of VFs that should be enabled on the PF; the value written + should be less than or equal to the value in the sriov_totalvfs + file. A userspace application wanting to disable the VFs would + write a zero to this file. The core ensures that valid values + are written to this file, and returns errors when values are not + valid. For example, writing a 2 to this file when sriov_numvfs + is not 0 and not 2 already will return an error. Writing a 10 + when the value of sriov_totalvfs is 8 will return an error. -- cgit v1.2.3