From 8d85a7a4f2c935013a01964b7e81d5a105bd7a4c Mon Sep 17 00:00:00 2001 From: Jakub Kicinski <jakub.kicinski@netronome.com> Date: Fri, 25 May 2018 08:18:34 -0500 Subject: [PATCH] PCI/IOV: Allow PF drivers to limit total_VFs to 0 Some SR-IOV PF drivers implement .sriov_configure(), which allows user-space to enable VFs by writing the desired number of VFs to the sysfs "sriov_numvfs" file (see sriov_numvfs_store()). The PCI core limits the number of VFs to the TotalVFs advertised by the device in its SR-IOV capability. The PF driver can limit the number of VFs to even fewer (it may have pre-allocated data structures or knowledge of device limitations) by calling pci_sriov_set_totalvfs(), but previously it could not limit the VFs to 0. Change pci_sriov_get_totalvfs() so it always respects the VF limit imposed by the PF driver, even if the limit is 0. This sequence: pci_sriov_set_totalvfs(dev, 0); x = pci_sriov_get_totalvfs(dev); previously set "x" to TotalVFs from the SR-IOV capability. Now it will set "x" to 0. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> [bhelgaas: split to separate patch] Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> --- drivers/pci/iov.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c index 192b82898a3842..d0d73dbbd5ca41 100644 --- a/drivers/pci/iov.c +++ b/drivers/pci/iov.c @@ -469,6 +469,7 @@ found: iov->nres = nres; iov->ctrl = ctrl; iov->total_VFs = total; + iov->driver_max_VFs = total; pci_read_config_word(dev, pos + PCI_SRIOV_VF_DID, &iov->vf_device); iov->pgsz = pgsz; iov->self = dev; @@ -827,10 +828,7 @@ int pci_sriov_get_totalvfs(struct pci_dev *dev) if (!dev->is_physfn) return 0; - if (dev->sriov->driver_max_VFs) - return dev->sriov->driver_max_VFs; - - return dev->sriov->total_VFs; + return dev->sriov->driver_max_VFs; } EXPORT_SYMBOL_GPL(pci_sriov_get_totalvfs); -- GitLab