pc: acpi: generate AML only for PCI0 devices if PCI bridge hotplug is disabled
Fixes migration regression from QEMU-1.7 to a newer QEMUs.
SSDT table size in QEMU-1.7 doesn't change regardless of
a number of PCI bridge devices present at startup.
However in QEMU-2.0 since addition of hotplug on PCI bridges,
each PCI bridge adds ~1875 bytes to SSDT table, including
pc-i440fx-1.7 machine type where PCI bridge hotplug disabled
via compat property.
It breaks migration from "QEMU-1.7" to "QEMU-2.[01] -M pc-i440fx-1.7"
since RAMBlock size of ACPI tables on target becomes larger
then on source and migration fails with:
"Length mismatch: /rom@etc/acpi/tables: 2000 in != 3000"
error.
Fix this by generating AML only for PCI0 bus if
hotplug on PCI bridges is disabled and preserves PCI brigde
description in AML as it was done in QEMU-1.7 for pc-i440fx-1.7.
It will help to maintain size of SSDT static regardless of
number of PCI bridges on startup for pc-i440fx-1.7 machine type.
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index d90c471..779160f 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -74,6 +74,7 @@
typedef struct AcpiPmInfo {
bool s3_disabled;
bool s4_disabled;
+ bool pcihp_bridge_en;
uint8_t s4_val;
uint16_t sci_int;
uint8_t acpi_enable_cmd;
@@ -95,6 +96,7 @@
GArray *device_table;
GArray *notify_table;
struct AcpiBuildPciBusHotplugState *parent;
+ bool pcihp_bridge_en;
} AcpiBuildPciBusHotplugState;
static void acpi_get_dsdt(AcpiMiscInfo *info)
@@ -198,6 +200,9 @@
NULL);
pm->gpe0_blk_len = object_property_get_int(obj, ACPI_PM_PROP_GPE0_BLK_LEN,
NULL);
+ pm->pcihp_bridge_en =
+ object_property_get_bool(obj, "acpi-pci-hotplug-with-bridge-support",
+ NULL);
}
static void acpi_get_misc_info(AcpiMiscInfo *info)
@@ -778,11 +783,13 @@
}
static void build_pci_bus_state_init(AcpiBuildPciBusHotplugState *state,
- AcpiBuildPciBusHotplugState *parent)
+ AcpiBuildPciBusHotplugState *parent,
+ bool pcihp_bridge_en)
{
state->parent = parent;
state->device_table = build_alloc_array();
state->notify_table = build_alloc_array();
+ state->pcihp_bridge_en = pcihp_bridge_en;
}
static void build_pci_bus_state_cleanup(AcpiBuildPciBusHotplugState *state)
@@ -796,7 +803,7 @@
AcpiBuildPciBusHotplugState *parent = parent_state;
AcpiBuildPciBusHotplugState *child = g_malloc(sizeof *child);
- build_pci_bus_state_init(child, parent);
+ build_pci_bus_state_init(child, parent, parent->pcihp_bridge_en);
return child;
}
@@ -817,6 +824,14 @@
GArray *method;
bool bus_hotplug_support = false;
+ /*
+ skip bridge subtree creation if bridge hotplug is disabled
+ to make it compatible with 1.7 machine type
+ */
+ if (!child->pcihp_bridge_en && bus->parent_dev) {
+ return;
+ }
+
if (bus->parent_dev) {
op = 0x82; /* DeviceOp */
build_append_nameseg(bus_table, "S%.02X_",
@@ -863,7 +878,8 @@
pc = PCI_DEVICE_GET_CLASS(pdev);
dc = DEVICE_GET_CLASS(pdev);
- if (pc->class_id == PCI_CLASS_BRIDGE_ISA || pc->is_bridge) {
+ if (pc->class_id == PCI_CLASS_BRIDGE_ISA ||
+ (pc->is_bridge && child->pcihp_bridge_en)) {
set_bit(slot, slot_device_system);
}
@@ -875,7 +891,7 @@
}
}
- if (!dc->hotpluggable || pc->is_bridge) {
+ if (!dc->hotpluggable || (pc->is_bridge && child->pcihp_bridge_en)) {
clear_bit(slot, slot_hotplug_enable);
}
}
@@ -1140,7 +1156,7 @@
bus = PCI_HOST_BRIDGE(pci_host)->bus;
}
- build_pci_bus_state_init(&hotplug_state, NULL);
+ build_pci_bus_state_init(&hotplug_state, NULL, pm->pcihp_bridge_en);
if (bus) {
/* Scan all PCI buses. Generate tables to support hotplug. */
