[Qemu-devel] [PATCH RFC 14/17] hw/pci: piix - suport multiple host bridges

[Marcel Apfelbaum <marcel@redhat.com>]

From: Marcel Apfelbaum <marcel.a@redhat.com>

Instead of assuming it has only one bus, it
enumerates all the host bridges until it finds
the one with bus number corresponding with the
config register.

Signed-off-by: Marcel Apfelbaum <marcel@redhat.com>
---
 hw/pci-host/piix.c | 57 +++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 56 insertions(+), 1 deletion(-)

diff --git a/hw/pci-host/piix.c b/hw/pci-host/piix.c
index 970b9e9..7310b4c 100644
--- a/hw/pci-host/piix.c
+++ b/hw/pci-host/piix.c
@@ -255,6 +255,61 @@ static void i440fx_pcihost_get_pci_hole64_end(Object *obj, Visitor *v,
     visit_type_uint64(v, &w64.end, name, errp);
 }
 
+static PCIBus *i440fx_find_primary_bus(int bus_num)
+{
+    PCIHostState *host;
+    PCIBus *bus = NULL;
+    int current = -1;
+
+    HOST_BRIDGE_FOREACH(host) {
+        int b = pci_bus_num(host->bus);
+        if (b <= bus_num && b > current) {
+            current = b;
+            bus = host->bus;
+        }
+    }
+
+    return bus;
+}
+
+static void i440fx_pcihost_data_write(void *opaque, hwaddr addr,
+                                      uint64_t val, unsigned len)
+{
+    uint32_t config_reg = PCI_HOST_BRIDGE(opaque)->config_reg;
+
+    if (config_reg & (1u << 31)) {
+        int bus_num = (config_reg >> 16) & 0xFF;
+        PCIBus *bus = i440fx_find_primary_bus(bus_num);
+
+        if (bus) {
+            pci_data_write(bus, config_reg | (addr & 3), val, len);
+        }
+    }
+}
+
+static uint64_t i440fx_pcihost_data_read(void *opaque,
+                                         hwaddr addr, unsigned len)
+{
+    uint32_t config_reg = PCI_HOST_BRIDGE(opaque)->config_reg;
+
+    if (config_reg & (1U << 31)) {
+        int bus_num = (config_reg >> 16) & 0xFF;
+        PCIBus *bus = i440fx_find_primary_bus(bus_num);
+
+        if (bus) {
+            return pci_data_read(bus, config_reg | (addr & 3), len);
+        }
+    }
+
+    return 0xffffffff;
+}
+
+const MemoryRegionOps i440fx_pcihost_data_le_ops = {
+    .read = i440fx_pcihost_data_read,
+    .write = i440fx_pcihost_data_write,
+    .endianness = DEVICE_LITTLE_ENDIAN,
+};
+
 static void i440fx_pcihost_initfn(Object *obj)
 {
     PCIHostState *s = PCI_HOST_BRIDGE(obj);
@@ -262,7 +317,7 @@ static void i440fx_pcihost_initfn(Object *obj)
 
     memory_region_init_io(&s->conf_mem, obj, &pci_host_conf_le_ops, s,
                           "pci-conf-idx", 4);
-    memory_region_init_io(&s->data_mem, obj, &pci_host_data_le_ops, s,
+    memory_region_init_io(&s->data_mem, obj, &i440fx_pcihost_data_le_ops, s,
                           "pci-conf-data", 4);
 
     object_property_add(obj, PCI_HOST_PROP_PCI_HOLE_START, "int",
-- 
2.1.0