xen PV passthru: assign SR-IOV virtual functions to separate virtual slots

VFs are reported as single-function devices in PCI_HEADER_TYPE, which
causes pci_scan_slot() in the PV domU to skip all VFs beyond #0 in the
pciback-provided slot. Avoid this by assigning each VF to a separate
virtual slot.

Acked-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

1 files changed, 10 insertions, 4 deletions

diff --git a/drivers/xen/xen-pciback/vpci.c b/drivers/xen/xen-pciback/vpci.c
index 46d140baebd8..0f478ac483cd 100644
--- a/drivers/xen/xen-pciback/vpci.c
+++ b/drivers/xen/xen-pciback/vpci.c
@@ -89,9 +89,15 @@ static int __xen_pcibk_add_pci_dev(struct xen_pcibk_device *pdev,
 
         mutex_lock(&vpci_dev->lock);
 
-        /* Keep multi-function devices together on the virtual PCI bus */
-        for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
-                if (!list_empty(&vpci_dev->dev_list[slot])) {
+        /*
+         * Keep multi-function devices together on the virtual PCI bus, except
+         * virtual functions.
+         */
+        if (!dev->is_virtfn) {
+                for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
+                        if (list_empty(&vpci_dev->dev_list[slot]))
+                                continue;
+
                         t = list_entry(list_first(&vpci_dev->dev_list[slot]),
                                        struct pci_dev_entry, list);
 
@@ -116,7 +122,7 @@ static int __xen_pcibk_add_pci_dev(struct xen_pcibk_device *pdev,
                                pci_name(dev), slot);
                         list_add_tail(&dev_entry->list,
                                       &vpci_dev->dev_list[slot]);
-                        func = PCI_FUNC(dev->devfn);
+                        func = dev->is_virtfn ? 0 : PCI_FUNC(dev->devfn);
                         goto unlock;
                 }
         }