• Bjorn Helgaas's avatar
    PCI: Don't look for ACPI hotplug parameters if ACPI is disabled · 8647ca9a
    Bjorn Helgaas authored
    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: [<c06ed0e6>] acpi_ns_validate_handle+0x12/0x1a
      Call Trace:
       [<c06eda4d>] ? acpi_evaluate_object+0x31/0x1fc
       [<c06b78e1>] ? pci_get_hp_params+0x111/0x4e0
       [<c0407bc7>] ? xen_force_evtchn_callback+0x17/0x30
       [<c04085fb>] ? xen_restore_fl_direct_reloc+0x4/0x4
       [<c0699d34>] ? 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: 6cd33649 ("PCI: Add pci_configure_device() during enumeration")
    Link: https://bugzilla.kernel.org/show_bug.cgi?id=96301Reported-by: default avatarMichael D Labriola <mlabriol@gdeb.com>
    Tested-by: default avatarMichael D Labriola <mlabriol@gdeb.com>
    Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
    CC: stable@vger.kernel.org	# v3.18+
    8647ca9a
pci-acpi.c 15.8 KB