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-driver.c | 22 ++++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-) (limited to 'drivers/pci/pci-driver.c') diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index afa72717a979..f99f7fe749b8 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -394,6 +394,18 @@ void __weak pcibios_free_irq(struct pci_dev *dev) { } +#ifdef CONFIG_PCI_IOV +static inline bool pci_device_can_probe(struct pci_dev *pdev) +{ + return (!pdev->is_virtfn || pdev->physfn->sriov->drivers_autoprobe); +} +#else +static inline bool pci_device_can_probe(struct pci_dev *pdev) +{ + return true; +} +#endif + static int pci_device_probe(struct device *dev) { int error; @@ -405,10 +417,12 @@ static int pci_device_probe(struct device *dev) return error; pci_dev_get(pci_dev); - error = __pci_device_probe(drv, pci_dev); - if (error) { - pcibios_free_irq(pci_dev); - pci_dev_put(pci_dev); + if (pci_device_can_probe(pci_dev)) { + error = __pci_device_probe(drv, pci_dev); + if (error) { + pcibios_free_irq(pci_dev); + pci_dev_put(pci_dev); + } } return error; -- cgit