Re: [Qemu-devel] [PATCH v3 6/6] hw/arm/virt: Support dynamically spawned sysbus devices

[Paolo Bonzini <pbonzini@redhat.com>]

Il 09/09/2014 09:54, Eric Auger ha scritto:
> Allows sysbus devices to be instantiated from command line by
> using -device option
> 
> Signed-off-by: Alexander Graf <agraf@suse.de>
> Signed-off-by: Eric Auger <eric.auger@linaro.org>
> 
> ---
> 
> 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
> ---
>  hw/arm/dyn_sysbus_devtree.c | 26 +++++++++++++++++++
>  hw/arm/virt.c               | 62 +++++++++++++++++++++++++++++++++++++++++++--
>  2 files changed, 86 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/arm/dyn_sysbus_devtree.c b/hw/arm/dyn_sysbus_devtree.c
> index 6375024..61e5b5f 100644
> --- a/hw/arm/dyn_sysbus_devtree.c
> +++ b/hw/arm/dyn_sysbus_devtree.c
> @@ -1,7 +1,30 @@
> +/*
> + * ARM Platform Bus device tree generation helpers 
> + *
> + * Copyright (c) 2014 Linaro Limited
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2 or later, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
> + * more details.
> + *
> + * You should have received a copy of the GNU General Public License along with
> + * this program.  If not, see <http://www.gnu.org/licenses/>.
> + *
> + */
> +
>  #include "hw/arm/dyn_sysbus_devtree.h"
>  #include "qemu/error-report.h"
>  #include "sysemu/device_tree.h"
>  
> +/**
> + * arm_sysbus_device_create_devtree - create the node of devices
> + * attached to the platform bus
> + */
>  static int arm_sysbus_device_create_devtree(Object *obj, void *opaque)
>  {
>      PlatformDevtreeData *data = opaque;
> @@ -27,6 +50,9 @@ static int arm_sysbus_device_create_devtree(Object *obj, void *opaque)
>      return 0;
>  }
>  
> +/**
> + * arm_platform_bus_create_devtree - create the platform bus node
> + */
>  void arm_platform_bus_create_devtree(DynSysbusParams *params,
>                                   void *fdt, const char *intc)
>  {

All this should go in patch 2.  For the documentation comments, please
follow the model of include/hw/memory.h (including putting the
documentation in the header for public functions).

> diff --git a/hw/arm/virt.c b/hw/arm/virt.c
> index 9085b88..16acf44 100644
> --- a/hw/arm/virt.c
> +++ b/hw/arm/virt.c
> @@ -40,6 +40,8 @@
>  #include "exec/address-spaces.h"
>  #include "qemu/bitops.h"
>  #include "qemu/error-report.h"
> +#include "hw/misc/dyn_sysbus_binding.h"
> +#include "hw/arm/dyn_sysbus_devtree.h"
>  
>  #define NUM_VIRTIO_TRANSPORTS 32
>  
> @@ -57,6 +59,14 @@
>  #define GIC_FDT_IRQ_PPI_CPU_START 8
>  #define GIC_FDT_IRQ_PPI_CPU_WIDTH 8
>  
> +#define MACHVIRT_PLATFORM_BASE         0x9400000
> +#define MACHVIRT_PLATFORM_SIZE         (4ULL * 1024 * 1024) /* 4 MB */
> +#define MACHVIRT_PLATFORM_PAGE_SHIFT   12
> +#define MACHVIRT_PLATFORM_SIZE_PAGES   (MACHVIRT_PLATFORM_SIZE >> \
> +                                    MACHVIRT_PLATFORM_PAGE_SHIFT)
> +#define MACHVIRT_PLATFORM_FIRST_IRQ    48
> +#define MACHVIRT_PLATFORM_NUM_IRQS     20
> +
>  enum {
>      VIRT_FLASH,
>      VIRT_MEM,
> @@ -66,6 +76,7 @@ enum {
>      VIRT_UART,
>      VIRT_MMIO,
>      VIRT_RTC,
> +    VIRT_PLATFORM,
>  };
>  
>  typedef struct MemMapEntry {
> @@ -105,16 +116,27 @@ static const MemMapEntry a15memmap[] = {
>      [VIRT_GIC_CPU] =    { 0x08010000, 0x00010000 },
>      [VIRT_UART] =       { 0x09000000, 0x00001000 },
>      [VIRT_RTC] =        { 0x09010000, 0x00001000 },
> +    [VIRT_PLATFORM] = {MACHVIRT_PLATFORM_BASE , MACHVIRT_PLATFORM_SIZE},
>      [VIRT_MMIO] =       { 0x0a000000, 0x00000200 },
>      /* ...repeating for a total of NUM_VIRTIO_TRANSPORTS, each of that size */
>      /* 0x10000000 .. 0x40000000 reserved for PCI */
> -    [VIRT_MEM] =        { 0x40000000, 30ULL * 1024 * 1024 * 1024 },
> +    [VIRT_MEM] = { 0x40000000, 30ULL * 1024 * 1024 * 1024 },
>  };
>  
>  static const int a15irqmap[] = {
>      [VIRT_UART] = 1,
>      [VIRT_RTC] = 2,
>      [VIRT_MMIO] = 16, /* ...to 16 + NUM_VIRTIO_TRANSPORTS - 1 */
> +    [VIRT_PLATFORM] = MACHVIRT_PLATFORM_FIRST_IRQ,
> +};
> +
> +static DynSysbusParams dyn_sysbus_platform_params = {
> +    .has_platform_bus = true,
> +    .platform_bus_base = MACHVIRT_PLATFORM_BASE,
> +    .platform_bus_size = MACHVIRT_PLATFORM_SIZE,
> +    .platform_bus_first_irq = MACHVIRT_PLATFORM_FIRST_IRQ,
> +    .platform_bus_num_irqs = MACHVIRT_PLATFORM_NUM_IRQS,
> +    .page_shift = MACHVIRT_PLATFORM_PAGE_SHIFT,
>  };
>  
>  static VirtBoardInfo machines[] = {
> @@ -458,6 +480,18 @@ static void create_virtio_devices(const VirtBoardInfo *vbi, qemu_irq *pic)
>      fdt_add_virtio_nodes(vbi);
>  }
>  
> +static void machvirt_prep_device_tree(VirtBoardInfo *vbi)
> +{
> +    create_fdt(vbi);
> +    fdt_add_timer_nodes(vbi);
> +    fdt_add_cpu_nodes(vbi);
> +    fdt_add_psci_node(vbi);
> +    fdt_add_gic_node(vbi);
> +    fdt_add_uart_node(vbi);
> +    fdt_add_rtc_node(vbi);
> +    fdt_add_virtio_nodes(vbi);
> +}
> +
>  static void *machvirt_dtb(const struct arm_boot_info *binfo, int *fdt_size)
>  {
>      const VirtBoardInfo *board = (const VirtBoardInfo *)binfo;
> @@ -466,14 +500,28 @@ static void *machvirt_dtb(const struct arm_boot_info *binfo, int *fdt_size)
>      return board->fdt;
>  }
>  
> +static void machvirt_reset_device_tree(void *opaque)
> +{
> +    VirtBoardInfo *board = (VirtBoardInfo *)opaque;
> +    struct arm_boot_info *info = &board->bootinfo;
> +    hwaddr dtb_start = QEMU_ALIGN_UP(info->initrd_start + info->initrd_size,
> +                                     4096);
> +    machvirt_prep_device_tree(board);
> +    arm_platform_bus_create_devtree(&dyn_sysbus_platform_params,
> +                                board->fdt, "/intc");

Why do you have to recreate the device tree every time (as opposed to
just doing the load)?  And if arm_load_dtb used rom_add_blob_fixed
instead of cpu_physical_memory_write, you wouldn't need a reset hook at all.

Paolo

> +    arm_load_dtb(dtb_start, info);
> +}
> +
>  static void machvirt_init(MachineState *machine)
>  {
> -    qemu_irq pic[NUM_IRQS];
> +    qemu_irq *pic = g_new(qemu_irq, NUM_IRQS);
>      MemoryRegion *sysmem = get_system_memory();
>      int n;
>      MemoryRegion *ram = g_new(MemoryRegion, 1);
>      const char *cpu_model = machine->cpu_model;
>      VirtBoardInfo *vbi;
> +    DynSysbusNotifier *notifier;
>  
>      if (!cpu_model) {
>          cpu_model = "cortex-a15";
> @@ -547,6 +595,13 @@ static void machvirt_init(MachineState *machine)
>       */
>      create_virtio_devices(vbi, pic);
>  
> +    notifier = g_new(DynSysbusNotifier, 1);
> +    notifier->notifier.notify = platform_bus_init_notify;
> +    notifier->address_space_mem = sysmem;
> +    notifier->mpic = pic;
> +    notifier->params = dyn_sysbus_platform_params;
> +    qemu_add_machine_init_done_notifier(&notifier->notifier);
> +
>      vbi->bootinfo.ram_size = machine->ram_size;
>      vbi->bootinfo.kernel_filename = machine->kernel_filename;
>      vbi->bootinfo.kernel_cmdline = machine->kernel_cmdline;
> @@ -556,6 +611,8 @@ static void machvirt_init(MachineState *machine)
>      vbi->bootinfo.loader_start = vbi->memmap[VIRT_MEM].base;
>      vbi->bootinfo.get_dtb = machvirt_dtb;
>      arm_load_kernel(ARM_CPU(first_cpu), &vbi->bootinfo);
> +
> +    qemu_register_reset(machvirt_reset_device_tree, vbi);
>  }
>  
>  static QEMUMachine machvirt_a15_machine = {
> @@ -563,6 +620,7 @@ 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)
>