From 8647ca9ad5a0065ad53a2ad7e39163592b6ed35e Mon Sep 17 00:00:00 2001 From: Bjorn Helgaas Date: Tue, 24 Mar 2015 11:12:45 -0500 Subject: [PATCH] PCI: Don't look for ACPI hotplug parameters if ACPI is disabled Booting a v3.18 or newer Xen domU kernel with PCI devices passed through results in an oops (this is a 32-bit 3.13.11 dom0 with a 64-bit 4.4.0 hypervisor and 32-bit domU): BUG: unable to handle kernel paging request at 0030303e IP: [] acpi_ns_validate_handle+0x12/0x1a Call Trace: [] ? acpi_evaluate_object+0x31/0x1fc [] ? pci_get_hp_params+0x111/0x4e0 [] ? xen_force_evtchn_callback+0x17/0x30 [] ? xen_restore_fl_direct_reloc+0x4/0x4 [] ? pci_device_add+0x24/0x450 Don't look for ACPI configuration information if ACPI has been disabled. I don't think this is the best fix, because we can boot plain Linux (no Xen) with "acpi=off", and we don't need this check in pci_get_hp_params(). There should be a better fix that would make Xen domU work the same way. The domU kernel has ACPI support but it has no AML. There should be a way to initialize the ACPI data structures so things fail gracefully rather than oopsing. This is an interim fix to address the regression. Fixes: 6cd33649fa83 ("PCI: Add pci_configure_device() during enumeration") Link: https://bugzilla.kernel.org/show_bug.cgi?id=96301 Reported-by: Michael D Labriola Tested-by: Michael D Labriola Signed-off-by: Bjorn Helgaas CC: stable@vger.kernel.org # v3.18+ --- drivers/pci/pci-acpi.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c index 489063987325..c93fbe76d281 100644 --- a/drivers/pci/pci-acpi.c +++ b/drivers/pci/pci-acpi.c @@ -248,6 +248,9 @@ int pci_get_hp_params(struct pci_dev *dev, struct hotplug_params *hpp) acpi_handle handle, phandle; struct pci_bus *pbus; + if (acpi_pci_disabled) + return -ENODEV; + handle = NULL; for (pbus = dev->bus; pbus; pbus = pbus->parent) { handle = acpi_pci_get_bridge_handle(pbus);