PCI/MSI: Fix MSI IRQ domains for VFs on virtual buses (38ea72bd) · Commits · 戴 / test

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: ("PCI/MSI: Add hooks to populate the msi_domain field") Tested-by:

Joerg Roedel <joro@8bytes.org> Signed-off-by:

Alex Williamson <alex.williamson@redhat.com> Signed-off-by:

Bjorn Helgaas <helgaas@kernel.org> Acked-by:

Marc Zyngier <marc.zyngier@arm.com>

drivers/pci/probe.c

+11 −6

Original line number	Diff line number	Diff line
		@@ -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);
		}

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