[+cc Greg] I plan to apply this to my -next branch today and anticipate merging during the v3.8 merge window, probably next week. So speak up now with any concerns :) The related code is already in my -next branch. On Tue, Nov 27, 2012 at 8:31 PM, Donald Dutile <ddutile@xxxxxxxxxx> wrote: > Signed-off: Donald Dutile <ddutile@xxxxxxxxxx> > > --- > Documentation/ABI/testing/sysfs-bus-pci | 34 +++++++++++++++++++++++ > Documentation/PCI/pci-iov-howto.txt | 48 ++++++++++++++++++++++++++++++--- > 2 files changed, 78 insertions(+), 4 deletions(-) > > diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci > index dff1f48..1cb389d 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 <ddutile@xxxxxxxxxx> > +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_ This should be just "sriov_numvfs", not "sriov_numvfs_", right? > +Date: November 2012 > +Contact: Donald Dutile <ddutile@xxxxxxxxxx> > +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. > diff --git a/Documentation/PCI/pci-iov-howto.txt b/Documentation/PCI/pci-iov-howto.txt > index fc73ef5..c41cf95 100644 > --- a/Documentation/PCI/pci-iov-howto.txt > +++ b/Documentation/PCI/pci-iov-howto.txt > @@ -2,6 +2,9 @@ > Copyright (C) 2009 Intel Corporation > Yu Zhao <yu.zhao@xxxxxxxxx> > > + Update: November 2012 > + -- sysfs-based SRIOV enable-/disable-ment > + Donald Dutile <ddutile@xxxxxxxxxx> > > 1. Overview > > @@ -24,10 +27,21 @@ real existing PCI device. > > 2.1 How can I enable SR-IOV capability > > -The device driver (PF driver) will control the enabling and disabling > -of the capability via API provided by SR-IOV core. If the hardware > -has SR-IOV capability, loading its PF driver would enable it and all > -VFs associated with the PF. > +Multiple methods are available for SR-IOV enablement. > +In the first method, the device driver (PF driver) will control the > +enabling and disabling of the capability via API provided by SR-IOV core. > +If the hardware has SR-IOV capability, loading its PF driver would > +enable it and all VFs associated with the PF. Some PF drivers require > +a module parameter to be set to determine the number of VFs to enable. > +In the second method, a write to the sysfs file sriov_numvfs will > +enable and disable the VFs associated with a PCIe PF. This method > +enables per-PF, VF enable/disable values versus the first method, > +which applies to all PFs of the same device. Additionally, the > +PCI SRIOV core support ensures that enable/disable operations are > +valid to reduce duplication in multiple drivers for the same > +checks, e.g., check numvfs == 0 if enabling VFs, ensure > +numvfs <= totalvfs. > +The second method is the recommended method for new/future VF devices. > > 2.2 How can I use the Virtual Functions > > @@ -40,13 +54,22 @@ requires device driver that is same as a normal PCI device's. > 3.1 SR-IOV API > > To enable SR-IOV capability: > +(a) For the first method, in the driver: > int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn); > 'nr_virtfn' is number of VFs to be enabled. > +(b) For the second method, from sysfs: > + echo 'nr_virtfn' > \ > + /sys/bus/pci/devices/<DOMAIN:BUS:DEVICE.FUNCTION>/sriov_numvfs > > To disable SR-IOV capability: > +(a) For the first method, in the driver: > void pci_disable_sriov(struct pci_dev *dev); > +(b) For the second method, from sysfs: > + echo 0 > \ > + /sys/bus/pci/devices/<DOMAIN:BUS:DEVICE.FUNCTION>/sriov_numvfs > > To notify SR-IOV core of Virtual Function Migration: > +(a) In the driver: > irqreturn_t pci_sriov_migration(struct pci_dev *dev); > > 3.2 Usage example > @@ -88,6 +111,22 @@ static void dev_shutdown(struct pci_dev *dev) > ... > } > > +static int dev_sriov_configure(struct pci_dev *dev, int numvfs) > +{ > + if (numvfs > 0) { > + ... > + pci_enable_sriov(dev, numvfs); > + ... > + return numvfs; > + } > + if (numvfs == 0) { > + .... > + pci_disable_sriov(dev); > + ... > + return 0; > + } > +} > + > static struct pci_driver dev_driver = { > .name = "SR-IOV Physical Function driver", > .id_table = dev_id_table, > @@ -96,4 +135,5 @@ static struct pci_driver dev_driver = { > .suspend = dev_suspend, > .resume = dev_resume, > .shutdown = dev_shutdown, > + .sriov_configure = dev_sriov_configure, > }; > -- > 1.7.10.2.552.gaa3bb87 > -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html