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acpi: x86: pcihp: add support hotplug on multifunction bridges 

Commit [1] switched PCI hotplug from native to ACPI one by default.

That however breaks hotplug on following CLI that used to work:
   -nodefaults -machine q35 \
   -device pcie-root-port,id=pcie-root-port-0,multifunction=on,bus=pcie.0,addr=0x1,chassis=1 \
   -device pcie-root-port,id=pcie-root-port-1,port=0x1,addr=0x1.0x1,bus=pcie.0,chassis=2

where PCI device is hotplugged to pcie-root-port-1 with error on guest side:

  ACPI BIOS Error (bug): Could not resolve symbol [^S0B.PCNT], AE_NOT_FOUND (20201113/psargs-330)
  ACPI Error: Aborting method \_SB.PCI0.PCNT due to previous error (AE_NOT_FOUND) (20201113/psparse-531)
  ACPI Error: Aborting method \_GPE._E01 due to previous error (AE_NOT_FOUND) (20201113/psparse-531)
  ACPI Error: AE_NOT_FOUND, while evaluating GPE method [_E01] (20201113/evgpe-515)

cause is that QEMU's ACPI hotplug never supported functions other then 0
and due to bug it was generating notification entries for not described
functions.

Technically there is no reason not to describe cold-plugged bridges
(root ports) on functions other then 0, as they similarly to bridge
on function 0 are unpluggable.

So since we need to describe multifunction devices iterate over
fuctions as well. But describe only cold-plugged bridges[root ports]
on functions other than 0 as well.

1)
Fixes: 17858a1695 (hw/acpi/ich9: Set ACPI PCI hot-plug as default on Q35)
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reported-by: Laurent Vivier <lvivier@redhat.com>
Message-Id: <20210723090424.2092226-1-imammedo@redhat.com>
Fixes: 17858a1695 (hw/acpi/ich9: Set ACPI PCI hot-plug as default on Q35)<br>
Signed-off-by: Igor Mammedov &lt;<a href="mailto:imammedo@redhat.com" target="_blank">imammedo@redhat.com</a>&gt;<br>
Reported-by: Laurent Vivier &lt;<a href="mailto:lvivier@redhat.com" target="_blank">lvivier@redhat.com</a>&gt;<br>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Igor Mammedov 2021-07-23 05:04:24 -04:00 committed by Michael S. Tsirkin
parent e2a6290aab
commit d7346e614f
1 changed files with 30 additions and 14 deletions
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44
hw/i386/acpi-build.c
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@ -374,7 +374,7 @@ static void build_append_pci_bus_devices(Aml *parent_scope, PCIBus *bus,
Aml *dev, *notify_method = NULL, *method;
QObject *bsel;
PCIBus *sec;
int i;
int devfn;
bsel = object_property_get_qobject(OBJECT(bus), ACPI_PCIHP_PROP_BSEL, NULL);
if (bsel) {
@ -384,23 +384,31 @@ static void build_append_pci_bus_devices(Aml *parent_scope, PCIBus *bus,
notify_method = aml_method("DVNT", 2, AML_NOTSERIALIZED);
}
for (i = 0; i < ARRAY_SIZE(bus->devices); i += PCI_FUNC_MAX) {
for (devfn = 0; devfn < ARRAY_SIZE(bus->devices); devfn++) {
DeviceClass *dc;
PCIDeviceClass *pc;
PCIDevice *pdev = bus->devices[i];
int slot = PCI_SLOT(i);
PCIDevice *pdev = bus->devices[devfn];
int slot = PCI_SLOT(devfn);
int func = PCI_FUNC(devfn);
/* ACPI spec: 1.0b: Table 6-2 _ADR Object Bus Types, PCI type */
int adr = slot << 16 | func;
bool hotplug_enabled_dev;
bool bridge_in_acpi;
bool cold_plugged_bridge;
if (!pdev) {
if (bsel) { /* add hotplug slots for non present devices */
/*
* add hotplug slots for non present devices.
* hotplug is supported only for non-multifunction device
* so generate device description only for function 0
*/
if (bsel && !func) {
if (pci_bus_is_express(bus) && slot > 0) {
break;
}
dev = aml_device("S%.02X", PCI_DEVFN(slot, 0));
dev = aml_device("S%.02X", devfn);
aml_append(dev, aml_name_decl("_SUN", aml_int(slot)));
aml_append(dev, aml_name_decl("_ADR", aml_int(slot << 16)));
aml_append(dev, aml_name_decl("_ADR", aml_int(adr)));
method = aml_method("_EJ0", 1, AML_NOTSERIALIZED);
aml_append(method,
aml_call2("PCEJ", aml_name("BSEL"), aml_name("_SUN"))
@ -436,9 +444,18 @@ static void build_append_pci_bus_devices(Aml *parent_scope, PCIBus *bus,
continue;
}
/* start to compose PCI slot descriptor */
dev = aml_device("S%.02X", PCI_DEVFN(slot, 0));
aml_append(dev, aml_name_decl("_ADR", aml_int(slot << 16)));
/*
* allow describing coldplugged bridges in ACPI even if they are not
* on function 0, as they are not unpluggable, for all other devices
* generate description only for function 0 per slot
*/
if (func && !bridge_in_acpi) {
continue;
}
/* start to compose PCI device descriptor */
dev = aml_device("S%.02X", devfn);
aml_append(dev, aml_name_decl("_ADR", aml_int(adr)));
if (bsel) {
/*
@ -496,7 +513,7 @@ static void build_append_pci_bus_devices(Aml *parent_scope, PCIBus *bus,
build_append_pci_bus_devices(dev, sec_bus, pcihp_bridge_en);
}
/* slot descriptor has been composed, add it into parent context */
/* device descriptor has been composed, add it into parent context */
aml_append(parent_scope, dev);
}
@ -525,13 +542,12 @@ static void build_append_pci_bus_devices(Aml *parent_scope, PCIBus *bus,
/* Notify about child bus events in any case */
if (pcihp_bridge_en) {
QLIST_FOREACH(sec, &bus->child, sibling) {
int32_t devfn = sec->parent_dev->devfn;
if (pci_bus_is_root(sec)) {
continue;
}
aml_append(method, aml_name("^S%.02X.PCNT", devfn));
aml_append(method, aml_name("^S%.02X.PCNT",
sec->parent_dev->devfn));
}
}