[Qemu-devel] [PATCH V3 2/3] hw/pxb: introduce pxb-pcie expander for PCIe machines

[Marcel Apfelbaum <marcel@redhat.com>]

The pxb-pcie is the counterpart of pxb for PCI express machines.
The new device re-uses the pxb code, but appears to the guests
as a different device. The pxb-pcie device does not have an internal
pci-pci bridge and exposes a PCIe root bus instead of a PCI one.

Signed-off-by: Marcel Apfelbaum <marcel@redhat.com>
---
 hw/pci-bridge/pci_expander_bridge.c | 98 +++++++++++++++++++++++++++++++------
 include/hw/pci/pci.h                |  1 +
 2 files changed, 84 insertions(+), 15 deletions(-)

diff --git a/hw/pci-bridge/pci_expander_bridge.c b/hw/pci-bridge/pci_expander_bridge.c
index 57f8a37..bb98fb2 100644
--- a/hw/pci-bridge/pci_expander_bridge.c
+++ b/hw/pci-bridge/pci_expander_bridge.c
@@ -23,6 +23,9 @@
 #define TYPE_PXB_BUS "pxb-bus"
 #define PXB_BUS(obj) OBJECT_CHECK(PXBBus, (obj), TYPE_PXB_BUS)
 
+#define TYPE_PXB_PCIE_BUS "pxb-pcie-bus"
+#define PXB_PCIE_BUS(obj) OBJECT_CHECK(PXBBus, (obj), TYPE_PXB_PCIE_BUS)
+
 typedef struct PXBBus {
     /*< private >*/
     PCIBus parent_obj;
@@ -34,6 +37,9 @@ typedef struct PXBBus {
 #define TYPE_PXB_DEVICE "pxb"
 #define PXB_DEV(obj) OBJECT_CHECK(PXBDev, (obj), TYPE_PXB_DEVICE)
 
+#define TYPE_PXB_PCIE_DEVICE "pxb-pcie"
+#define PXB_PCIE_DEV(obj) OBJECT_CHECK(PXBDev, (obj), TYPE_PXB_PCIE_DEVICE)
+
 typedef struct PXBDev {
     /*< private >*/
     PCIDevice parent_obj;
@@ -43,13 +49,18 @@ typedef struct PXBDev {
     uint16_t numa_node;
 } PXBDev;
 
+static PXBDev *convert_to_pxb(PCIDevice *dev)
+{
+    return pci_bus_is_express(dev->bus) ? PXB_PCIE_DEV(dev) : PXB_DEV(dev);
+}
+
 static GList *pxb_dev_list;
 
 #define TYPE_PXB_HOST "pxb-host"
 
 static int pxb_bus_num(PCIBus *bus)
 {
-    PXBDev *pxb = PXB_DEV(bus->parent_dev);
+    PXBDev *pxb = convert_to_pxb(bus->parent_dev);
 
     return pxb->bus_nr;
 }
@@ -61,7 +72,7 @@ static bool pxb_is_root(PCIBus *bus)
 
 static uint16_t pxb_bus_numa_node(PCIBus *bus)
 {
-    PXBDev *pxb = PXB_DEV(bus->parent_dev);
+    PXBDev *pxb = convert_to_pxb(bus->parent_dev);
 
     return pxb->numa_node;
 }
@@ -82,10 +93,18 @@ static const TypeInfo pxb_bus_info = {
     .class_init    = pxb_bus_class_init,
 };
 
+static const TypeInfo pxb_pcie_bus_info = {
+    .name          = TYPE_PXB_PCIE_BUS,
+    .parent        = TYPE_PCIE_BUS,
+    .instance_size = sizeof(PXBBus),
+    .class_init    = pxb_bus_class_init,
+};
+
 static const char *pxb_host_root_bus_path(PCIHostState *host_bridge,
                                           PCIBus *rootbus)
 {
-    PXBBus *bus = PXB_BUS(rootbus);
+    PXBBus *bus = pci_bus_is_express(rootbus) ?
+                  PXB_PCIE_BUS(rootbus) : PXB_BUS(rootbus);
 
     snprintf(bus->bus_path, 8, "0000:%02x", pxb_bus_num(rootbus));
     return bus->bus_path;
@@ -103,7 +122,7 @@ static char *pxb_host_ofw_unit_address(const SysBusDevice *dev)
 
     pxb_host = PCI_HOST_BRIDGE(dev);
     pxb_bus = pxb_host->bus;
-    pxb_dev = PXB_DEV(pxb_bus->parent_dev);
+    pxb_dev = convert_to_pxb(pxb_bus->parent_dev);
     position = g_list_index(pxb_dev_list, pxb_dev);
     assert(position >= 0);
 
@@ -193,10 +212,10 @@ static gint pxb_compare(gconstpointer a, gconstpointer b)
            0;
 }
 
-static int pxb_dev_initfn(PCIDevice *dev)
+static int pxb_dev_init_common(PCIDevice *dev, bool pcie)
 {
-    PXBDev *pxb = PXB_DEV(dev);
-    DeviceState *ds, *bds;
+    PXBDev *pxb = convert_to_pxb(dev);
+    DeviceState *ds, *bds = NULL;
     PCIBus *bus;
     const char *dev_name = NULL;
 
@@ -211,18 +230,21 @@ static int pxb_dev_initfn(PCIDevice *dev)
     }
 
     ds = qdev_create(NULL, TYPE_PXB_HOST);
-    bus = pci_bus_new(ds, "pxb-internal", NULL, NULL, 0, TYPE_PXB_BUS);
+    if (pcie) {
+        bus = pci_bus_new(ds, dev_name, NULL, NULL, 0, TYPE_PXB_PCIE_BUS);
+    } else {
+        bus = pci_bus_new(ds, "pxb-internal", NULL, NULL, 0, TYPE_PXB_BUS);
+        bds = qdev_create(BUS(bus), "pci-bridge");
+        bds->id = dev_name;
+        qdev_prop_set_uint8(bds, PCI_BRIDGE_DEV_PROP_CHASSIS_NR, pxb->bus_nr);
+        qdev_prop_set_bit(bds, PCI_BRIDGE_DEV_PROP_SHPC, false);
+    }
 
     bus->parent_dev = dev;
     bus->address_space_mem = dev->bus->address_space_mem;
     bus->address_space_io = dev->bus->address_space_io;
     bus->map_irq = pxb_map_irq_fn;
 
-    bds = qdev_create(BUS(bus), "pci-bridge");
-    bds->id = dev_name;
-    qdev_prop_set_uint8(bds, PCI_BRIDGE_DEV_PROP_CHASSIS_NR, pxb->bus_nr);
-    qdev_prop_set_bit(bds, PCI_BRIDGE_DEV_PROP_SHPC, false);
-
     PCI_HOST_BRIDGE(ds)->bus = bus;
 
     if (pxb_register_bus(dev, bus)) {
@@ -230,7 +252,9 @@ static int pxb_dev_initfn(PCIDevice *dev)
     }
 
     qdev_init_nofail(ds);
-    qdev_init_nofail(bds);
+    if (bds) {
+        qdev_init_nofail(bds);
+    }
 
     pci_word_test_and_set_mask(dev->config + PCI_STATUS,
                                PCI_STATUS_66MHZ | PCI_STATUS_FAST_BACK);
@@ -240,9 +264,19 @@ static int pxb_dev_initfn(PCIDevice *dev)
     return 0;
 }
 
+static int pxb_dev_initfn(PCIDevice *dev)
+{
+    if (pci_bus_is_express(dev->bus)) {
+        error_report("pxb devices cannot reside on a PCIe bus!");
+        return -EINVAL;
+    }
+
+    return pxb_dev_init_common(dev, false);
+}
+
 static void pxb_dev_exitfn(PCIDevice *pci_dev)
 {
-    PXBDev *pxb = PXB_DEV(pci_dev);
+    PXBDev *pxb = convert_to_pxb(pci_dev);
 
     pxb_dev_list = g_list_remove(pxb_dev_list, pxb);
 }
@@ -276,11 +310,45 @@ static const TypeInfo pxb_dev_info = {
     .class_init    = pxb_dev_class_init,
 };
 
+static int pxb_pcie_dev_initfn(PCIDevice *dev)
+{
+    if (!pci_bus_is_express(dev->bus)) {
+        error_report("pxb-pcie devices cannot reside on a PCI bus!");
+        return -EINVAL;
+    }
+
+    return pxb_dev_init_common(dev, true);
+}
+
+static void pxb_pcie_dev_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
+
+    k->init = pxb_pcie_dev_initfn;
+    k->exit = pxb_dev_exitfn;
+    k->vendor_id = PCI_VENDOR_ID_REDHAT;
+    k->device_id = PCI_DEVICE_ID_REDHAT_PXB_PCIE;
+    k->class_id = PCI_CLASS_BRIDGE_HOST;
+
+    dc->desc = "PCI Express Expander Bridge";
+    dc->props = pxb_dev_properties;
+}
+
+static const TypeInfo pxb_pcie_dev_info = {
+    .name          = TYPE_PXB_PCIE_DEVICE,
+    .parent        = TYPE_PCI_DEVICE,
+    .instance_size = sizeof(PXBDev),
+    .class_init    = pxb_pcie_dev_class_init,
+};
+
 static void pxb_register_types(void)
 {
     type_register_static(&pxb_bus_info);
+    type_register_static(&pxb_pcie_bus_info);
     type_register_static(&pxb_host_info);
     type_register_static(&pxb_dev_info);
+    type_register_static(&pxb_pcie_dev_info);
 }
 
 type_init(pxb_register_types)
diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
index 379b6e1..dedf277 100644
--- a/include/hw/pci/pci.h
+++ b/include/hw/pci/pci.h
@@ -93,6 +93,7 @@
 #define PCI_DEVICE_ID_REDHAT_PCIE_HOST   0x0008
 #define PCI_DEVICE_ID_REDHAT_PXB         0x0009
 #define PCI_DEVICE_ID_REDHAT_BRIDGE_SEAT 0x000a
+#define PCI_DEVICE_ID_REDHAT_PXB_PCIE    0x000b
 #define PCI_DEVICE_ID_REDHAT_QXL         0x0100
 
 #define FMT_PCIBUS                      PRIx64
-- 
2.1.0