[Qemu-devel] [PATCH V6 for-2.3 15/26] hw/acpi: add support for i440fx 'snooping' root busses

[Marcel Apfelbaum <marcel@redhat.com>]

If the machine has extra root busses that are snooping to
the i440fx host bridge, we need to add them to
acpi in order to be properly detected by guests.

Signed-off-by: Marcel Apfelbaum <marcel@redhat.com>
---
 hw/i386/acpi-build.c | 30 ++++++++++++++++++++++++++++--
 hw/pci-host/piix.c   |  4 ++--
 include/hw/i386/pc.h |  2 +-
 3 files changed, 31 insertions(+), 5 deletions(-)

diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index 86e474a..ecd5684 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -60,6 +60,8 @@
 #include "qom/qom-qobject.h"
 #include "exec/ram_addr.h"
 
+#include "qmp-commands.h"
+
 /* These are used to size the ACPI tables for -M pc-i440fx-1.7 and
  * -M pc-i440fx-2.0.  Even if the actual amount of AML generated grows
  * a little bit, there should be plenty of free space since the DSDT
@@ -491,10 +493,11 @@ static void *acpi_set_bsel(PCIBus *bus, void *opaque)
 
 static void acpi_set_pci_info(void)
 {
-    PCIBus *bus = find_i440fx(); /* TODO: Q35 support */
+    PCIHostState *host = find_i440fx();
     unsigned bsel_alloc = 0;
 
-    if (bus) {
+    if (host) {
+        PCIBus *bus = host->bus; /* TODO: Q35 support */
         /* Scan all PCI buses. Set property to enable acpi based hotplug. */
         pci_for_each_bus_depth_first(bus, acpi_set_bsel, NULL, &bsel_alloc);
     }
@@ -660,6 +663,7 @@ build_ssdt(GArray *table_data, GArray *linker,
     uint32_t nr_mem = machine->ram_slots;
     unsigned acpi_cpus = guest_info->apic_id_limit;
     Aml *ssdt, *sb_scope, *scope, *pkg, *dev, *method, *crs, *field, *ifctx;
+    PCIHostState *snooped_host;
     int i;
 
     ssdt = init_aml_allocator();
@@ -671,6 +675,28 @@ build_ssdt(GArray *table_data, GArray *linker,
     /* Reserve space for header */
     acpi_data_push(ssdt->buf, sizeof(AcpiTableHeader));
 
+    /* Snooping mechanism is implemented only for i440fx */
+    snooped_host = find_i440fx();
+    if (snooped_host) {
+        PCIHostBridgeSnoopedClass *snooped_class =
+            PCI_HOST_BRIDGE_SNOOPED_GET_CLASS(snooped_host);
+        GPtrArray *snooping_hosts = snooped_class->snooping_hosts(snooped_host);
+
+        for (i = 0; i < snooping_hosts->len; i++) {
+            PCIHostState *host = g_ptr_array_index(snooping_hosts, i);
+            uint8_t bus_num = pci_bus_num(host->bus);
+
+            scope = aml_scope("\\_SB");
+            dev = aml_device("PC%.02X", bus_num);
+            aml_append(dev,
+                       aml_name_decl("_UID", aml_string("PC%.02X", bus_num)));
+            aml_append(dev, aml_name_decl("_HID", aml_string("PNP0A03")));
+            aml_append(dev, aml_name_decl("_BBN", aml_int(bus_num)));
+            aml_append(scope, dev);
+            aml_append(ssdt, scope);
+        }
+    }
+
     scope = aml_scope("\\_SB.PCI0");
     /* build PCI0._CRS */
     crs = aml_resource_template();
diff --git a/hw/pci-host/piix.c b/hw/pci-host/piix.c
index f512765..50418ca 100644
--- a/hw/pci-host/piix.c
+++ b/hw/pci-host/piix.c
@@ -464,12 +464,12 @@ PCIBus *i440fx_init(PCII440FXState **pi440fx_state,
     return b;
 }
 
-PCIBus *find_i440fx(void)
+PCIHostState *find_i440fx(void)
 {
     PCIHostState *s = OBJECT_CHECK(PCIHostState,
                                    object_resolve_path("/machine/i440fx", NULL),
                                    TYPE_PCI_HOST_BRIDGE);
-    return s ? s->bus : NULL;
+    return s;
 }
 
 /*
diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
index a918a61..7c89fae 100644
--- a/include/hw/i386/pc.h
+++ b/include/hw/i386/pc.h
@@ -240,7 +240,7 @@ PCIBus *i440fx_init(PCII440FXState **pi440fx_state, int *piix_devfn,
                     MemoryRegion *pci_memory,
                     MemoryRegion *ram_memory);
 
-PCIBus *find_i440fx(void);
+PCIHostState *find_i440fx(void);
 /*
  * Register hosts without their own configuration registers
  * to i440fx main PCI host bridge
-- 
2.1.0