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PCI: acpiphp: Reassign resources on bridge if necessary

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When using ACPI PCI hotplug, hotplugging a device with large BARs may fail
if bridge windows programmed by firmware are not large enough.

Reproducer:
  $ qemu-kvm -monitor stdio -M q35  -m 4G \
      -global ICH9-LPC.acpi-pci-hotplug-with-bridge-support=on \
      -device id=rp1,pcie-root-port,bus=pcie.0,chassis=4 \
      disk_image

 wait till linux guest boots, then hotplug device:
   (qemu) device_add qxl,bus=rp1

 hotplug on guest side fails with:
   pci 0000:01:00.0: [1b36:0100] type 00 class 0x038000
   pci 0000:01:00.0: reg 0x10: [mem 0x00000000-0x03ffffff]
   pci 0000:01:00.0: reg 0x14: [mem 0x00000000-0x03ffffff]
   pci 0000:01:00.0: reg 0x18: [mem 0x00000000-0x00001fff]
   pci 0000:01:00.0: reg 0x1c: [io  0x0000-0x001f]
   pci 0000:01:00.0: BAR 0: no space for [mem size 0x04000000]
   pci 0000:01:00.0: BAR 0: failed to assign [mem size 0x04000000]
   pci 0000:01:00.0: BAR 1: no space for [mem size 0x04000000]
   pci 0000:01:00.0: BAR 1: failed to assign [mem size 0x04000000]
   pci 0000:01:00.0: BAR 2: assigned [mem 0xfe800000-0xfe801fff]
   pci 0000:01:00.0: BAR 3: assigned [io  0x1000-0x101f]
   qxl 0000:01:00.0: enabling device (0000 -> 0003)
   Unable to create vram_mapping
   qxl: probe of 0000:01:00.0 failed with error -12

However when using native PCIe hotplug
  '-global ICH9-LPC.acpi-pci-hotplug-with-bridge-support=off'
it works fine, since kernel attempts to reassign unused resources.

Use the same machinery as native PCIe hotplug to (re)assign resources.

Link: https://lore.kernel.org/r/20230424191557.2464760-1-imammedo@redhat.com
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Cc: stable@vger.kernel.org
This commit is contained in:
Igor Mammedov 2023-04-24 21:15:57 +02:00 committed by Bjorn Helgaas
parent e8afd0d9fc
commit 40613da52b
1 changed files with 1 additions and 4 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

5
drivers/pci/hotplug/acpiphp_glue.c
View file

@ -498,7 +498,6 @@ static void enable_slot(struct acpiphp_slot *slot, bool bridge)
acpiphp_native_scan_bridge(dev);
}
} else {
LIST_HEAD(add_list);
int max, pass;
acpiphp_rescan_slot(slot);
@ -512,12 +511,10 @@ static void enable_slot(struct acpiphp_slot *slot, bool bridge)
if (pass && dev->subordinate) {
check_hotplug_bridge(slot, dev);
pcibios_resource_survey_bus(dev->subordinate);
__pci_bus_size_bridges(dev->subordinate,
&add_list);
}
}
}
__pci_bus_assign_resources(bus, &add_list, NULL);
pci_assign_unassigned_bridge_resources(bus->self);
}
acpiphp_sanitize_bus(bus);