[Qemu-devel] [PATCH v5 6/6] hw/arm/virt: add dynamic sysbus device support

[Eric Auger <eric.auger@linaro.org>]

Allows sysbus devices to be instantiated from command line by
using -device option. Machvirt creates a platform bus at init.
The dynamic sysbus devices are attached to this platform bus device.

The platform bus device registers a machine init done notifier
whose role will be to bind the dynamic sysbus devices. Indeed
dynamic sysbus devices are created after machine init.

machvirt also registers a notifier that will build the device
tree nodes for the platform bus and its children dynamic sysbus
devices.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Eric Auger <eric.auger@linaro.org>

---
v4 -> v5:
- platform_bus_params becomes static const
- reword comment in create_platform_bus
- reword the commit message

v3 -> v4:
- use platform bus object, instantiated in create_platform_bus
- device tree generation for platform bus and children dynamic
  sysbus devices is no more handled at reset but in a
  machine_init_done_notifier (due to the change in implementaion
  of ARM load dtb using rom_add_blob_fixed).
- device tree enhancement now takes into account the case of
  user provided dtb. Before the user dtb was overwritten which
  was wrong. However in case the dtb is provided by the user,
  dynamic sysbus nodes are not added there.
- renaming of MACHVIRT_PLATFORM defines
- MACHVIRT_PLATFORM_PAGE_SHIFT and SIZE_PAGES not needed anymore,
  hence removed.
- DynSysbusParams struct renamed into ARMPlatformBusSystemParams
  and above params removed.
- separation of dt creation and QEMU binding is not mandated anymore
  since the device tree is not created from scratch anymore. Instead
  the modify_dtb function is used.
- create_platform_bus registers another machine init done notifier
  to start VFIO IRQ handling. This latter executes after the
  dynamic sysbus device binding.

v2 -> v3:
- renaming of arm_platform_bus_create_devtree and arm_load_dtb
- add copyright in hw/arm/dyn_sysbus_devtree.c

v1 -> v2:
- remove useless vfio-platform.h include file
- s/MACHVIRT_PLATFORM_HOLE/MACHVIRT_PLATFORM_SIZE
- use dyn_sysbus_binding and dyn_sysbus_devtree
- dynamic sysbus platform buse size shrinked to 4MB and
  moved between RTC and MMIO

v1:

Inspired from what Alex Graf did in ppc e500
https://lists.gnu.org/archive/html/qemu-ppc/2014-07/msg00012.html

Conflicts:
	hw/arm/sysbus-fdt.c
---
 hw/arm/virt.c | 57 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)

diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index 314e55b..37326a9 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -42,6 +42,8 @@
 #include "exec/address-spaces.h"
 #include "qemu/bitops.h"
 #include "qemu/error-report.h"
+#include "hw/arm/sysbus-fdt.h"
+#include "hw/platform-bus.h"
 
 #define NUM_VIRTIO_TRANSPORTS 32
 
@@ -59,6 +61,11 @@
 #define GIC_FDT_IRQ_PPI_CPU_START 8
 #define GIC_FDT_IRQ_PPI_CPU_WIDTH 8
 
+#define PLATFORM_BUS_BASE         0x9400000
+#define PLATFORM_BUS_SIZE         (4ULL * 1024 * 1024)
+#define PLATFORM_BUS_FIRST_IRQ    48
+#define PLATFORM_BUS_NUM_IRQS     20
+
 enum {
     VIRT_FLASH,
     VIRT_MEM,
@@ -68,6 +75,7 @@ enum {
     VIRT_UART,
     VIRT_MMIO,
     VIRT_RTC,
+    VIRT_PLATFORM_BUS,
 };
 
 typedef struct MemMapEntry {
@@ -107,6 +115,7 @@ static const MemMapEntry a15memmap[] = {
     [VIRT_GIC_CPU] =    { 0x08010000, 0x00010000 },
     [VIRT_UART] =       { 0x09000000, 0x00001000 },
     [VIRT_RTC] =        { 0x09010000, 0x00001000 },
+    [VIRT_PLATFORM_BUS] = {PLATFORM_BUS_BASE , PLATFORM_BUS_SIZE},
     [VIRT_MMIO] =       { 0x0a000000, 0x00000200 },
     /* ...repeating for a total of NUM_VIRTIO_TRANSPORTS, each of that size */
     /* 0x10000000 .. 0x40000000 reserved for PCI */
@@ -117,6 +126,14 @@ static const int a15irqmap[] = {
     [VIRT_UART] = 1,
     [VIRT_RTC] = 2,
     [VIRT_MMIO] = 16, /* ...to 16 + NUM_VIRTIO_TRANSPORTS - 1 */
+    [VIRT_PLATFORM_BUS] = PLATFORM_BUS_FIRST_IRQ,
+};
+
+static const ARMPlatformBusSystemParams platform_bus_params = {
+    .platform_bus_base = PLATFORM_BUS_BASE,
+    .platform_bus_size = PLATFORM_BUS_SIZE,
+    .platform_bus_first_irq = PLATFORM_BUS_FIRST_IRQ,
+    .platform_bus_num_irqs = PLATFORM_BUS_NUM_IRQS,
 };
 
 static VirtBoardInfo machines[] = {
@@ -519,6 +536,43 @@ static void create_flash(const VirtBoardInfo *vbi)
     g_free(nodename);
 }
 
+static void create_platform_bus(VirtBoardInfo *vbi, qemu_irq *pic,
+                                const ARMPlatformBusSystemParams *system_params)
+{
+    DeviceState *dev;
+    SysBusDevice *s;
+    int i;
+    ARMPlatformBusFdtParams *fdt_params = g_new(ARMPlatformBusFdtParams, 1);
+    MemoryRegion *sysmem = get_system_memory();
+
+    fdt_params->system_params = system_params;
+    fdt_params->binfo = &vbi->bootinfo;
+    fdt_params->intc = "/intc";
+    /*
+     * register a machine init done notifier that creates the device tree
+     * nodes of the platform bus and its children dynamic sysbus devices
+     */
+    arm_register_platform_bus_fdt_creator(fdt_params);
+
+    dev = qdev_create(NULL, TYPE_PLATFORM_BUS_DEVICE);
+    dev->id = TYPE_PLATFORM_BUS_DEVICE;
+    qdev_prop_set_uint32(dev, "num_irqs",
+        system_params->platform_bus_num_irqs);
+    qdev_prop_set_uint32(dev, "mmio_size",
+        system_params->platform_bus_size);
+    qdev_init_nofail(dev);
+    s = SYS_BUS_DEVICE(dev);
+
+    for (i = 0; i < system_params->platform_bus_num_irqs; i++) {
+        int irqn = system_params->platform_bus_first_irq + i;
+        sysbus_connect_irq(s, i, pic[irqn]);
+    }
+
+    memory_region_add_subregion(sysmem,
+                                system_params->platform_bus_base,
+                                sysbus_mmio_get_region(s, 0));
+}
+
 static void *machvirt_dtb(const struct arm_boot_info *binfo, int *fdt_size)
 {
     const VirtBoardInfo *board = (const VirtBoardInfo *)binfo;
@@ -604,6 +658,8 @@ static void machvirt_init(MachineState *machine)
      */
     create_virtio_devices(vbi, pic);
 
+    create_platform_bus(vbi, pic, &platform_bus_params);
+
     vbi->bootinfo.ram_size = machine->ram_size;
     vbi->bootinfo.kernel_filename = machine->kernel_filename;
     vbi->bootinfo.kernel_cmdline = machine->kernel_cmdline;
@@ -620,6 +676,7 @@ static QEMUMachine machvirt_a15_machine = {
     .desc = "ARM Virtual Machine",
     .init = machvirt_init,
     .max_cpus = 8,
+    .has_dynamic_sysbus = true,
 };
 
 static void machvirt_machine_init(void)
-- 
1.8.3.2