Re: [Qemu-devel] [PULL 20/22] hw/arm/boot: arm_load_kernel implemented as a machine init done notifier

[Eric Auger]

Hi Peter,
On 06/12/2015 04:54 AM, Peter Crosthwaite wrote:
> On Tue, Jun 2, 2015 at 9:33 AM, Peter Maydell <address@hidden> wrote:
>> From: Eric Auger <address@hidden>
>>
>> Device tree nodes for the platform bus and its children dynamic sysbus
>> devices are added in a machine init done notifier. To load the dtb once,
>> after those latter nodes are built and before ROM freeze, the actual
>> arm_load_kernel existing code is moved into a notifier notify function,
>> arm_load_kernel_notify. arm_load_kernel now only registers the
>> corresponding notifier.
>>
> 
> Does this work? I am experiencing a regression on this patch for
> xlnx-ep108 board.

Sorry for the inconvenience. On my side I tested it on virt board.

I am currently looking at the issue ...

Best Regards

Eric
 I think it is because this is now delaying
> arm_load_kernel_notify call until after rom_load_all. From vl.c:
> 
>     if (rom_load_all() != 0) {
>         fprintf(stderr, "rom loading failed\n");
>         exit(1);
>     }
> 
>     /* TODO: once all bus devices are qdevified, this should be done
>      * when bus is created by qdev.c */
>     qemu_register_reset(qbus_reset_all_fn, sysbus_get_default());
>     qemu_run_machine_init_done_notifiers();
> 
> the machine_init_done_notifiers are called after the rom_load_all()
> call which does the image loading. So the image-to-load registration
> is too late.
> 
> Straight revert of this patch fixes the issue for me.
> 
> Regards,
> Peter
> 
> 
>> Machine files that do not support platform bus stay unchanged. Machine
>> files willing to support dynamic sysbus devices must call arm_load_kernel
>> before sysbus-fdt arm_register_platform_bus_fdt_creator to make sure
>> dynamic sysbus device nodes are integrated in the dtb.
>>
>> Signed-off-by: Eric Auger <address@hidden>
>> Reviewed-by: Shannon Zhao <address@hidden>
>> Reviewed-by: Alexander Graf <address@hidden>
>> Reviewed-by: Alex Bennée <address@hidden>
>> Message-id: address@hidden
>> Signed-off-by: Peter Maydell <address@hidden>
>> ---
>>  hw/arm/boot.c        | 14 +++++++++++++-
>>  include/hw/arm/arm.h | 28 ++++++++++++++++++++++++++++
>>  2 files changed, 41 insertions(+), 1 deletion(-)
>>
>> diff --git a/hw/arm/boot.c b/hw/arm/boot.c
>> index fa69503..d036624 100644
>> --- a/hw/arm/boot.c
>> +++ b/hw/arm/boot.c
>> @@ -557,7 +557,7 @@ static void load_image_to_fw_cfg(FWCfgState *fw_cfg, 
>> uint16_t size_key,
>>      fw_cfg_add_bytes(fw_cfg, data_key, data, size);
>>  }
>>
>> -void arm_load_kernel(ARMCPU *cpu, struct arm_boot_info *info)
>> +static void arm_load_kernel_notify(Notifier *notifier, void *data)
>>  {
>>      CPUState *cs;
>>      int kernel_size;
>> @@ -568,6 +568,11 @@ void arm_load_kernel(ARMCPU *cpu, struct arm_boot_info 
>> *info)
>>      hwaddr entry, kernel_load_offset;
>>      int big_endian;
>>      static const ARMInsnFixup *primary_loader;
>> +    ArmLoadKernelNotifier *n = DO_UPCAST(ArmLoadKernelNotifier,
>> +                                         notifier, notifier);
>> +    ARMCPU *cpu = n->cpu;
>> +    struct arm_boot_info *info =
>> +        container_of(n, struct arm_boot_info, load_kernel_notifier);
>>
>>      /* CPU objects (unlike devices) are not automatically reset on system
>>       * reset, so we must always register a handler to do so. If we're
>> @@ -775,3 +780,10 @@ void arm_load_kernel(ARMCPU *cpu, struct arm_boot_info 
>> *info)
>>          ARM_CPU(cs)->env.boot_info = info;
>>      }
>>  }
>> +
>> +void arm_load_kernel(ARMCPU *cpu, struct arm_boot_info *info)
>> +{
>> +    info->load_kernel_notifier.cpu = cpu;
>> +    info->load_kernel_notifier.notifier.notify = arm_load_kernel_notify;
>> +    
>> qemu_add_machine_init_done_notifier(&info->load_kernel_notifier.notifier);
>> +}
>> diff --git a/include/hw/arm/arm.h b/include/hw/arm/arm.h
>> index 5c940eb..760804c 100644
>> --- a/include/hw/arm/arm.h
>> +++ b/include/hw/arm/arm.h
>> @@ -13,11 +13,21 @@
>>
>>  #include "exec/memory.h"
>>  #include "hw/irq.h"
>> +#include "qemu/notify.h"
>>
>>  /* armv7m.c */
>>  qemu_irq *armv7m_init(MemoryRegion *system_memory, int mem_size, int 
>> num_irq,
>>                        const char *kernel_filename, const char *cpu_model);
>>
>> +/*
>> + * struct used as a parameter of the arm_load_kernel machine init
>> + * done notifier
>> + */
>> +typedef struct {
>> +    Notifier notifier; /* actual notifier */
>> +    ARMCPU *cpu; /* handle to the first cpu object */
>> +} ArmLoadKernelNotifier;
>> +
>>  /* arm_boot.c */
>>  struct arm_boot_info {
>>      uint64_t ram_size;
>> @@ -64,6 +74,8 @@ struct arm_boot_info {
>>       * the user it should implement this hook.
>>       */
>>      void (*modify_dtb)(const struct arm_boot_info *info, void *fdt);
>> +    /* machine init done notifier executing arm_load_dtb */
>> +    ArmLoadKernelNotifier load_kernel_notifier;
>>      /* Used internally by arm_boot.c */
>>      int is_linux;
>>      hwaddr initrd_start;
>> @@ -75,6 +87,22 @@ struct arm_boot_info {
>>       */
>>      bool firmware_loaded;
>>  };
>> +
>> +/**
>> + * arm_load_kernel - Loads memory with everything needed to boot
>> + *
>> + * @cpu: handle to the first CPU object
>> + * @info: handle to the boot info struct
>> + * Registers a machine init done notifier that copies to memory
>> + * everything needed to boot, depending on machine and user options:
>> + * kernel image, boot loaders, initrd, dtb. Also registers the CPU
>> + * reset handler.
>> + *
>> + * In case the machine file supports the platform bus device and its
>> + * dynamically instantiable sysbus devices, this function must be called
>> + * before sysbus-fdt arm_register_platform_bus_fdt_creator. Indeed the
>> + * machine init done notifiers are called in registration reverse order.
>> + */
>>  void arm_load_kernel(ARMCPU *cpu, struct arm_boot_info *info);
>>
>>  /* Multiplication factor to convert from system clock ticks to qemu timer
>> --
>> 1.9.1
>>
>>