On Mon, Oct 1, 2012 at 4:27 PM, Donald Dutile <ddutile@xxxxxxxxxx> wrote:
> Provide files under sysfs to determine the max number of vfs
> an SRIOV-capable PCIe device supports, and methods to enable and
> disable the vfs on a per device basis.
>
> Currently, VF enablement by SRIOV-capable PCIe devices is done
> in driver-specific module parameters. If not setup in modprobe files,
> it requires admin to unload & reload PF drivers with number of desired
> VFs to enable. Additionally, the enablement is system wide: all
> devices controlled by the same driver have the same number of VFs
> enabled. Although the latter is probably desired, there are PCI
> configurations setup by system BIOS that may not enable that to occur.
>
> Three files are created if a PCIe device has SRIOV support:
> sriov_max_vfs -- cat-ing this file returns the maximum number
> of VFs a PCIe device supports.
> sriov_enable_vfs -- echo'ing a number to this file enables this
> number of VFs for this given PCIe device.
> -- cat-ing this file will return the number of VFs
> currently enabled on this PCIe device.
> sriov_disable_vfs -- echo-ing any number other than 0 disables all
> VFs associated with this PCIe device.
>
> VF enable and disablement is invoked much like other PCIe
> configuration functions -- via registered callbacks in the driver,
> i.e., probe, release, etc.
>
> Note: I haven't had a chance to refactor an SRIOV PF driver
> to test against; hoping to try ixgbe or igb in next couple days.
> To date, just tested that cat-ing sriov_max_vfs works, and
> cat-ing sriov_enable_vfs returns the correct number when
> a PF driver has been loaded with VFs enabled via per-driver param,
> e.g., modprobe igb max_vfs=4
>
> Send comments and I'll integrate as needed, while modifying
> a PF driver to use this interface.
>
> Signed-off-by: Donald Dutile <ddutile@xxxxxxxxxx>
>
> ---
> drivers/pci/pci-sysfs.c | 186 ++++++++++++++++++++++++++++++++++++++++++++----
> include/linux/pci.h | 2 +
> 2 files changed, 175 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
> index 6869009..1b5eab7 100644
> --- a/drivers/pci/pci-sysfs.c
> +++ b/drivers/pci/pci-sysfs.c
> @@ -404,6 +404,152 @@ static ssize_t d3cold_allowed_show(struct device *dev,
> }
> #endif
>
> +
> +#ifdef CONFIG_PCI_IOV
> +static ssize_t sriov_max_vfs_show(struct device *dev,
> + struct device_attribute *attr,
> + char *buf)
> +{
> + struct pci_dev *pdev;
> +
> + pdev = to_pci_dev(dev);
> + return sprintf (buf, "%u\n", pdev->sriov->total);
> +}
> +
> +bool pci_dev_has_sriov(struct pci_dev *pdev)
> +{
> + int ret = false;
> + int pos;
> +
> + if (!pci_is_pcie(pdev))
> + goto out;
> +
> + pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_SRIOV);
> + if (pos)
> + ret = true;
> +out:
> + return ret;
> +}
> +
> +static ssize_t sriov_enable_vfs_show(struct device *dev,
> + struct device_attribute *attr,
> + char *buf)
> +{
> + struct pci_dev *pdev;
> + int nr_virtfn = 0;
> +
> + pdev = to_pci_dev(dev);
> +
> + if (pci_dev_has_sriov(pdev))
> + nr_virtfn = pdev->sriov->nr_virtfn;
> +
> + return sprintf (buf, "%u\n", nr_virtfn);
> +}
> +
> +static ssize_t sriov_enable_vfs_store(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf, size_t count)
> +{
> + struct pci_dev *pdev;
> + int num_vf_enabled = 0;
> + unsigned long num_vfs;
> + pdev = to_pci_dev(dev);
> +
> + if (!pci_dev_has_sriov(pdev))
> + goto out;
> +
> + /* Requested VFs to enable < max_vfs
> + * and none enabled already
> + */
> + if (strict_strtoul(buf, 0, &num_vfs) < 0)
> + return -EINVAL;
> +
> + if ((num_vfs > pdev->sriov->total) ||
> + (pdev->sriov->nr_virtfn != 0))
> + return -EINVAL;
> +
> + /* Ready for lift-off! */
> + if (pdev->driver && pdev->driver->sriov_enable) {
> + num_vf_enabled = pdev->driver->sriov_enable(pdev, num_vfs);
> + }
> +
> +out:
> + if (num_vf_enabled != num_vfs)
> + printk(KERN_WARNING
> + "%s: %04x:%02x:%02x.%d: Only %d VFs enabled \n",
> + pci_name(pdev), pci_domain_nr(pdev->bus),
> + pdev->bus->number, PCI_SLOT(pdev->devfn),
> + PCI_FUNC(pdev->devfn), num_vf_enabled);
> +
> + return count;
> +}
> +
> +static ssize_t sriov_disable_vfs_store(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf, size_t count)
> +{
> + struct pci_dev *pdev;
> +
> + pdev = to_pci_dev(dev);
> +
> + /* make sure sriov device & at least 1 vf enabled */
> + if (!pci_dev_has_sriov(pdev) ||
> + (pdev->sriov->nr_virtfn == 0))
> + goto out;
> +
> + /* Ready for landing! */
> + if (pdev->driver && pdev->driver->sriov_disable) {
> + pdev->driver->sriov_disable(pdev);
> + }
> +out:
> + return count;
> +}
> +
> +struct device_attribute pci_dev_sriov_attrs[] = {
> + __ATTR_RO(sriov_max_vfs),
> + __ATTR(sriov_enable_vfs, (S_IRUGO|S_IWUSR|S_IWGRP),
> + sriov_enable_vfs_show, sriov_enable_vfs_store),
> + __ATTR(sriov_disable_vfs, (S_IWUSR|S_IWGRP),
> + NULL, sriov_disable_vfs_store),
> + __ATTR_NULL,
> +};
> +
> +static int pci_sriov_create_sysfs_dev_files(struct pci_dev *dev)
> +{
> + int pos, i;
> + int retval=0;
> +
> + if ((dev->is_physfn) && pci_is_pcie(dev)) {
> + pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_SRIOV);
> + if (pos) {
> + for (i = 0; attr_name(pci_dev_sriov_attrs[i]); i++) {
> + retval = device_create_file(&dev->dev, &pci_dev_sriov_attrs[i]);
> + if (retval) {
> + while (--i >= 0)
> + device_remove_file(&dev->dev, &pci_dev_sriov_attrs[i]);
> + break;
> + }
> + }
> + }
> + }
> + return retval;
> +}
> +
> +static void pci_sriov_remove_sysfs_dev_files(struct pci_dev *dev)
> +{
> + int pos;
> +
> + if ((dev->is_physfn) && pci_is_pcie(dev)) {
> + pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_SRIOV);
> + if (pos)
> + device_remove_file(&dev->dev, pci_dev_sriov_attrs);
> + }
> +}
...
> @@ -1203,14 +1365,18 @@ static int pci_create_capabilities_sysfs(struct pci_dev *dev)
> goto error;
> dev->reset_fn = 1;
> }
> +
> + /* SRIOV */
> + retval = pci_sriov_create_sysfs_dev_files(dev);
> + if (retval)
> + goto error;
> +
No, You should not use function for that.
According to Greg, you should use group visible to do that.
Please check the patches that i send out before.
here I attached them again.
Yinghai
Attachment:
pci_dev_type.patch
Description: Binary data
Attachment:
pci_010_pci_dev_boot_vga_x.patch
Description: Binary data
Attachment:
pci_drv_set_max_vfs.patch
Description: Binary data
Attachment:
sriov_xxx.patch
Description: Binary data
Attachment:
ixgbe_max_vfs.patch
Description: Binary data
