From 38ea72bdb65df2f40ec77b2c9d1413e7f5e34465 Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Fri, 18 Sep 2015 15:08:54 -0600 Subject: [PATCH] PCI/MSI: Fix MSI IRQ domains for VFs on virtual buses SR-IOV creates a virtual bus where bus->self is NULL. When we add VFs and scan for an MSI domain, pci_set_bus_msi_domain() dereferences bus->self, which causes a kernel NULL pointer dereference oops. Scan up to the parent bus until we find a real bridge where we can get the MSI domain. [bhelgaas: changelog] Fixes: 44aa0c657e3e ("PCI/MSI: Add hooks to populate the msi_domain field") Tested-by: Joerg Roedel Signed-off-by: Alex Williamson Signed-off-by: Bjorn Helgaas Acked-by: Marc Zyngier --- drivers/pci/probe.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index c8cc0e62a7b9..8361d27e5eca 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -676,15 +676,20 @@ static struct irq_domain *pci_host_bridge_msi_domain(struct pci_bus *bus) static void pci_set_bus_msi_domain(struct pci_bus *bus) { struct irq_domain *d; + struct pci_bus *b; /* - * Either bus is the root, and we must obtain it from the - * firmware, or we inherit it from the bridge device. + * The bus can be a root bus, a subordinate bus, or a virtual bus + * created by an SR-IOV device. Walk up to the first bridge device + * found or derive the domain from the host bridge. */ - if (pci_is_root_bus(bus)) - d = pci_host_bridge_msi_domain(bus); - else - d = dev_get_msi_domain(&bus->self->dev); + for (b = bus, d = NULL; !d && !pci_is_root_bus(b); b = b->parent) { + if (b->self) + d = dev_get_msi_domain(&b->self->dev); + } + + if (!d) + d = pci_host_bridge_msi_domain(b); dev_set_msi_domain(&bus->dev, d); }