From 0e7df22401a3dfd403b26dea62dd00e0598b538b Mon Sep 17 00:00:00 2001 From: Bodong Wang Date: Thu, 13 Apr 2017 01:51:40 +0300 Subject: PCI: Add sysfs sriov_drivers_autoprobe to control VF driver binding Sometimes it is not desirable to bind SR-IOV VFs to drivers. This can save host side resource usage by VF instances that will be assigned to VMs. Add a new PCI sysfs interface "sriov_drivers_autoprobe" to control that from the PF. To modify it, echo 0/n/N (disable probe) or 1/y/Y (enable probe) to: /sys/bus/pci/devices//sriov_drivers_autoprobe Note that this must be done before enabling VFs. The change will not take effect if VFs are already enabled. Simply, one can disable VFs by setting sriov_numvfs to 0, choose whether to probe or not, and then re-enable the VFs by restoring sriov_numvfs. [bhelgaas: changelog, ABI doc] Signed-off-by: Bodong Wang Signed-off-by: Eli Cohen Signed-off-by: Bjorn Helgaas Reviewed-by: Gavin Shan Reviewed-by: Alex Williamson --- drivers/pci/pci-sysfs.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) (limited to 'drivers/pci/pci-sysfs.c') diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index 25d010d449a3..369c999683ca 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -526,10 +526,37 @@ exit: return count; } +static ssize_t sriov_drivers_autoprobe_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct pci_dev *pdev = to_pci_dev(dev); + + return sprintf(buf, "%u\n", pdev->sriov->drivers_autoprobe); +} + +static ssize_t sriov_drivers_autoprobe_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct pci_dev *pdev = to_pci_dev(dev); + bool drivers_autoprobe; + + if (kstrtobool(buf, &drivers_autoprobe) < 0) + return -EINVAL; + + pdev->sriov->drivers_autoprobe = drivers_autoprobe; + + return count; +} + static struct device_attribute sriov_totalvfs_attr = __ATTR_RO(sriov_totalvfs); static struct device_attribute sriov_numvfs_attr = __ATTR(sriov_numvfs, (S_IRUGO|S_IWUSR|S_IWGRP), sriov_numvfs_show, sriov_numvfs_store); +static struct device_attribute sriov_drivers_autoprobe_attr = + __ATTR(sriov_drivers_autoprobe, (S_IRUGO|S_IWUSR|S_IWGRP), + sriov_drivers_autoprobe_show, sriov_drivers_autoprobe_store); #endif /* CONFIG_PCI_IOV */ static ssize_t driver_override_store(struct device *dev, @@ -1549,6 +1576,7 @@ static struct attribute_group pci_dev_hp_attr_group = { static struct attribute *sriov_dev_attrs[] = { &sriov_totalvfs_attr.attr, &sriov_numvfs_attr.attr, + &sriov_drivers_autoprobe_attr.attr, NULL, }; -- cgit v1.2.3