[PATCH v5 09/50] multi-process: setup PCI host bridge for remote device

[Jagannathan Raman <jag.raman@oracle.com>]

PCI host bridge is setup for the remote device process. It is
implemented using remote-pcihost object. It is an extension of the PCI
host bridge setup by QEMU.
Remote-pcihost configures a PCI bus which could be used by the remote
 PCI device to latch on to.

Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
Signed-off-by: John G Johnson <john.g.johnson@oracle.com>
Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
---
 v4 -> v5:
  - Setting PCI bus name on the fly
  - Unable to grab the PCI bus name from object hierarchy as
    RemPCIHost have access to it during instantiation

 hw/pci/Makefile.objs     |  2 +-
 include/remote/pcihost.h | 45 ++++++++++++++++++++++++++++++++++
 remote/Makefile.objs     |  1 +
 remote/pcihost.c         | 64 ++++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 111 insertions(+), 1 deletion(-)
 create mode 100644 include/remote/pcihost.h
 create mode 100644 remote/pcihost.c

diff --git a/hw/pci/Makefile.objs b/hw/pci/Makefile.objs
index 955be54..90693a7 100644
--- a/hw/pci/Makefile.objs
+++ b/hw/pci/Makefile.objs
@@ -13,6 +13,6 @@ common-obj-$(CONFIG_PCI_EXPRESS) += pcie_port.o pcie_host.o
 common-obj-$(call lnot,$(CONFIG_PCI)) += pci-stub.o
 common-obj-$(CONFIG_ALL) += pci-stub.o
 
-remote-pci-obj-$(CONFIG_MPQEMU) += pci.o pci_bridge.o
+remote-pci-obj-$(CONFIG_MPQEMU) += pci.o pci_bridge.o pci_host.o pcie_host.o
 remote-pci-obj-$(CONFIG_MPQEMU) += msi.o msix.o
 remote-pci-obj-$(CONFIG_MPQEMU) += pcie.o
diff --git a/include/remote/pcihost.h b/include/remote/pcihost.h
new file mode 100644
index 0000000..7aca9cc
--- /dev/null
+++ b/include/remote/pcihost.h
@@ -0,0 +1,45 @@
+/*
+ * PCI Host for remote device
+ *
+ * Copyright © 2018, 2020 Oracle and/or its affiliates.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#ifndef REMOTE_PCIHOST_H
+#define REMOTE_PCIHOST_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include "exec/memory.h"
+#include "hw/pci/pcie_host.h"
+
+#define TYPE_REMOTE_HOST_DEVICE "remote-pcihost"
+#define REMOTE_HOST_DEVICE(obj) \
+    OBJECT_CHECK(RemPCIHost, (obj), TYPE_REMOTE_HOST_DEVICE)
+
+typedef struct RemPCIHost {
+    /*< private >*/
+    PCIExpressHost parent_obj;
+    /*< public >*/
+
+    /*
+     * Memory Controller Hub (MCH) may not be necessary for the emulation
+     * program. The two important reasons for implementing a PCI host in the
+     * emulation program are:
+     * - Provide a PCI bus for IO devices
+     * - Enable translation of guest PA to the PCI bar regions
+     *
+     * For both the above mentioned purposes, it doesn't look like we would
+     * need the MCH
+     */
+
+    MemoryRegion *mr_pci_mem;
+    MemoryRegion *mr_sys_mem;
+    MemoryRegion *mr_sys_io;
+} RemPCIHost;
+
+#endif
diff --git a/remote/Makefile.objs b/remote/Makefile.objs
index a9b2256..2757f5a 100644
--- a/remote/Makefile.objs
+++ b/remote/Makefile.objs
@@ -1 +1,2 @@
 remote-pci-obj-$(CONFIG_MPQEMU) += remote-main.o
+remote-pci-obj-$(CONFIG_MPQEMU) += pcihost.o
diff --git a/remote/pcihost.c b/remote/pcihost.c
new file mode 100644
index 0000000..dbe0819
--- /dev/null
+++ b/remote/pcihost.c
@@ -0,0 +1,64 @@
+/*
+ * Remote PCI host device
+ *
+ * Copyright © 2018, 2020 Oracle and/or its affiliates.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "qemu/osdep.h"
+#include "hw/pci/pci.h"
+#include "hw/pci/pci_host.h"
+#include "hw/pci/pcie_host.h"
+#include "hw/qdev-properties.h"
+#include "remote/pcihost.h"
+#include "exec/memory.h"
+
+static const char *remote_host_root_bus_path(PCIHostState *host_bridge,
+                                             PCIBus *rootbus)
+{
+    return "0000:00";
+}
+
+static void remote_host_realize(DeviceState *dev, Error **errp)
+{
+    char *busname = g_strdup_printf("remote-pci-%ld", (unsigned long)getpid());
+    PCIHostState *pci = PCI_HOST_BRIDGE(dev);
+    RemPCIHost *s = REMOTE_HOST_DEVICE(dev);
+
+    pci->bus = pci_root_bus_new(DEVICE(s), busname,
+                                s->mr_pci_mem, s->mr_sys_io,
+                                0, TYPE_PCIE_BUS);
+}
+
+static void remote_host_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    PCIHostBridgeClass *hc = PCI_HOST_BRIDGE_CLASS(klass);
+
+    hc->root_bus_path = remote_host_root_bus_path;
+    dc->realize = remote_host_realize;
+
+    dc->user_creatable = false;
+    set_bit(DEVICE_CATEGORY_BRIDGE, dc->categories);
+    dc->fw_name = "pci";
+}
+
+static const TypeInfo remote_host_info = {
+    .name = TYPE_REMOTE_HOST_DEVICE,
+    .parent = TYPE_PCIE_HOST_BRIDGE,
+    .instance_size = sizeof(RemPCIHost),
+    .class_init = remote_host_class_init,
+};
+
+static void remote_machine_register(void)
+{
+    type_register_static(&remote_host_info);
+}
+
+type_init(remote_machine_register)
-- 
1.8.3.1