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/<DOMAIN:BUS:DEVICE.FUNCTION>/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 <bodong@mellanox.com>
Signed-off-by: Eli Cohen <eli@mellanox.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 25d010d..369c999 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -526,10 +526,37 @@
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 *sriov_dev_attrs[] = {
&sriov_totalvfs_attr.attr,
&sriov_numvfs_attr.attr,
+ &sriov_drivers_autoprobe_attr.attr,
NULL,
};