This is a note to let you know that I've just added the patch titled
PCI: acpiphp: Reassign resources on bridge if necessary
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
pci-acpiphp-reassign-resources-on-bridge-if-necessary.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 40613da52b13fb21c5566f10b287e0ca8c12c4e9 Mon Sep 17 00:00:00 2001
From: Igor Mammedov <imammedo@xxxxxxxxxx>
Date: Mon, 24 Apr 2023 21:15:57 +0200
Subject: PCI: acpiphp: Reassign resources on bridge if necessary
From: Igor Mammedov <imammedo@xxxxxxxxxx>
commit 40613da52b13fb21c5566f10b287e0ca8c12c4e9 upstream.
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@xxxxxxxxxx
Signed-off-by: Igor Mammedov <imammedo@xxxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Acked-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
Acked-by: Rafael J. Wysocki <rafael@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/pci/hotplug/acpiphp_glue.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)
--- a/drivers/pci/hotplug/acpiphp_glue.c
+++ b/drivers/pci/hotplug/acpiphp_glue.c
@@ -489,7 +489,6 @@ static void enable_slot(struct acpiphp_s
acpiphp_native_scan_bridge(dev);
}
} else {
- LIST_HEAD(add_list);
int max, pass;
acpiphp_rescan_slot(slot);
@@ -503,12 +502,10 @@ static void enable_slot(struct acpiphp_s
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);
Patches currently in stable-queue which might be from imammedo@xxxxxxxxxx are
queue-5.15/pci-acpiphp-reassign-resources-on-bridge-if-necessary.patch
