On 10/31/2012 07:47 PM, Ben Hutchings wrote:
On Wed, 2012-10-31 at 17:19 -0400, Donald Dutile 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_totalvfs -- cat-ing this file returns the maximum number of VFs a PCIe device supports as reported by the TotalVFs in the SRIOV ext cap structure. sriov_numvfs -- echo'ing a positive number to this file enables this number of VFs for this given PCIe device. -- echo'ing a 0 to this file disables any previously enabled VFs for this PCIe device. -- cat-ing this file will return the number of VFs currently enabled on this PCIe device, i.e., the NumVFs field in SRIOV ext. cap structure. VF enable and disablement is invoked much like other PCIe configuration functions -- via registered callbacks in the driver, i.e., probe, release, etc. Signed-off-by: Donald Dutile<ddutile@xxxxxxxxxx> --- drivers/pci/pci-sysfs.c | 137 +++++++++++++++++++++++++++++++++++++++++++++++- include/linux/pci.h | 1 + 2 files changed, 136 insertions(+), 2 deletions(-) diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index fbbb97f..83be8ce 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c[...]+static ssize_t sriov_numvfs_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct pci_dev *pdev; + int num_vfs_enabled = 0; + int num_vfs; + int ret = 0; + u16 total; + + pdev = to_pci_dev(dev); + + if (kstrtoint(buf, 0,&num_vfs)< 0) + return -EINVAL; + + /* is PF driver loaded w/callback */ + if (!pdev->driver || !pdev->driver->sriov_configure) { + dev_info(&pdev->dev, + "Driver doesn't support SRIOV configuration via sysfs\n"); + return -ENOSYS; + } + + /* if enabling vf's ... */ + total = pdev->sriov->total; + /* Requested VFs to enable< totalvfs and none enabled already */ + if ((num_vfs> 0)&& (num_vfs<= total)) { + if (pdev->sriov->nr_virtfn == 0) { + num_vfs_enabled = + pdev->driver->sriov_configure(pdev, num_vfs); + if ((num_vfs_enabled>= 0)&& + (num_vfs_enabled != num_vfs)) + dev_warn(&pdev->dev, + "Only %d VFs enabled\n", + num_vfs_enabled); + return count;If num_vfs_enabled< 0 then it's an error value which should be returned instead of count. [...]
agreed. will update.
@@ -1409,7 +1512,7 @@ static struct attribute *pci_dev_dev_attrs[] = { }; static umode_t pci_dev_attrs_are_visible(struct kobject *kobj, - struct attribute *a, int n) + struct attribute *a, int n) { struct device *dev = container_of(kobj, struct device, kobj); struct pci_dev *pdev = to_pci_dev(dev);This hunk should be folded into patch 1.
i removed it. will do a cleanup of this file in another patch.
@@ -1421,6 +1524,33 @@ static umode_t pci_dev_attrs_are_visible(struct kobject *kobj, return a->mode; } +#ifdef CONFIG_PCI_IOV +static struct attribute *sriov_dev_attrs[] = { + &sriov_totalvfs_attr.attr, + &sriov_numvfs_attr.attr, + NULL, +}; + +static umode_t sriov_attrs_are_visible(struct kobject *kobj, + struct attribute *a, int n) +{ + struct device *dev = container_of(kobj, struct device, kobj); + + if ((a ==&sriov_totalvfs_attr.attr) || + (a ==&sriov_numvfs_attr.attr)) { + if (!dev_is_pf(dev)) + return 0; + }Why do you check the attribute address? The whole group should be visible or invisible depending on dev_is_pf(). Any attributes that need another condition belong in another group.
agreed. it's a leftover design when it was part of the uber pci-dev attrs, but now that it's separate, dev_is_pf() is sufficient. good cleanup.
+ return a->mode; +} + +static struct attribute_group sriov_dev_attr_group = { + .attrs = sriov_dev_attrs, + .is_visible = sriov_attrs_are_visible, +}; +#endif /* CONFIG_PCI_IOV */[...]
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