Commit 17858a1695 (hw/acpi/ich9: Set ACPI PCI hot-plug as default on Q35)
switched PCI hotplug from native to ACPI one by default.
That however breaks ihotplug 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 similaraly to bridge
on function 0 are unpluggable.
Fix consists of describing cold-plugged bridges[root ports] on functions
other than 0.
Fixes: 17858a169508609ca9063c544833e5a1adeb7b52
Signed-off-by: Igor Mammedov <imamm...@redhat.com>
Reported-by: Laurent Vivier <lviv...@redhat.com>
---
hw/i386/acpi-build.c | 31 ++++++++++++++++++++++++-------
1 file changed, 24 insertions(+), 7 deletions(-)
diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index b40e284b72..77cb7a338a 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -364,7 +364,7 @@ static void build_append_pcihp_notify_entry(Aml *method,
int slot)
int32_t devfn = PCI_DEVFN(slot, 0);
if_ctx = aml_if(aml_and(aml_arg(0), aml_int(0x1U << slot), NULL));
- aml_append(if_ctx, aml_notify(aml_name("S%.02X", devfn), aml_arg(1)));
+ aml_append(if_ctx, aml_notify(aml_name("^S%.03X", devfn), aml_arg(1)));
aml_append(method, if_ctx);
}
@@ -389,18 +389,26 @@ static void build_append_pci_bus_devices(Aml
*parent_scope, PCIBus *bus,
PCIDeviceClass *pc;
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 && !PCI_FUNC(devfn)) {
if (pci_bus_is_express(bus) && slot > 0) {
break;
}
- dev = aml_device("S%.02X", PCI_DEVFN(slot, 0));
+ dev = aml_device("S%.03X", 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;
}
+ /*
+ * allow describing coldplugged bridges in ACPI even if they are not
+ * on function 0, as they are not unpluggale, for all other devices
+ * generate description only for function 0 per slot
+ */
+ if (PCI_FUNC(devfn) && !bridge_in_acpi) {
+ 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)));
+ dev = aml_device("S%.03X", devfn);
+ aml_append(dev, aml_name_decl("_ADR", aml_int(adr)));
if (bsel) {
/*
@@ -529,7 +546,7 @@ static void build_append_pci_bus_devices(Aml *parent_scope,
PCIBus *bus,
continue;
}
- aml_append(method, aml_name("^S%.02X.PCNT",
+ aml_append(method, aml_name("^S%.03X.PCNT",
sec->parent_dev->devfn));
}
}
--
2.27.0
