Re: [Qemu-devel] [PATCH v2 1/3] pc-dimm: add a function to calculate VM's current RAM size

[Igor Mammedov]

On Mon, 17 Nov 2014 13:11:08 +0800
zhanghailiang <address@hidden> wrote:

> The global parameter 'ram_size' does not take into account
> the hotplugged memory.
> 
> In some codes, we use 'ram_size' as current VM's real RAM size,
> which is not correct.
> 
> Add function 'get_current_ram_size' to calculate VM's current RAM
> size, it will enumerate present memory devices and also plus ram_size.
> 
> Signed-off-by: zhanghailiang <address@hidden>
> ---
>  hw/mem/pc-dimm.c                | 26 ++++++++++++++++++++++++++
>  include/exec/cpu-common.h       |  1 +
>  stubs/qmp_pc_dimm_device_list.c |  5 +++++
>  3 files changed, 32 insertions(+)
> 
> diff --git a/hw/mem/pc-dimm.c b/hw/mem/pc-dimm.c
> index a800ea7..38465d0 100644
> --- a/hw/mem/pc-dimm.c
> +++ b/hw/mem/pc-dimm.c
> @@ -62,6 +62,32 @@ int qmp_pc_dimm_device_list(Object *obj, void
> *opaque) return 0;
>  }
>  
> +ram_addr_t get_current_ram_size(void)
> +{
> +    MemoryDeviceInfoList *info_list = NULL;
> +    MemoryDeviceInfoList **prev = &info_list;

> +    MemoryDeviceInfoList *info;
> +    ram_addr_t size = ram_size;
> +
> +    qmp_pc_dimm_device_list(qdev_get_machine(), &prev);
> +    for (info = info_list; info; info = info->next) {
> +        MemoryDeviceInfo *value = info->value;
> +
> +        if (value) {
> +            switch (value->kind) {
> +            case MEMORY_DEVICE_INFO_KIND_DIMM:
> +                size += value->dimm->size;
> +                break;
> +            default:
> +                break;
> +            }
> +        }
> +    }
> +    qapi_free_MemoryDeviceInfoList(info_list);
> +
> +    return size;
> +}
function is a generic one and it could handle not only pc-dimm device
in future, so it would be better to put it in some device neutral place.

That would allow to drop following stub as well.

> +
>  static int pc_dimm_slot2bitmap(Object *obj, void *opaque)
>  {
>      unsigned long *bitmap = opaque;
> diff --git a/include/exec/cpu-common.h b/include/exec/cpu-common.h
> index 427b851..fcc3162 100644
> --- a/include/exec/cpu-common.h
> +++ b/include/exec/cpu-common.h
> @@ -52,6 +52,7 @@ typedef uintptr_t ram_addr_t;
>  #endif
>  
>  extern ram_addr_t ram_size;
> +ram_addr_t get_current_ram_size(void);
>  
>  /* memory API */
>  
> diff --git a/stubs/qmp_pc_dimm_device_list.c
> b/stubs/qmp_pc_dimm_device_list.c index 5cb220c..b584bd8 100644
> --- a/stubs/qmp_pc_dimm_device_list.c
> +++ b/stubs/qmp_pc_dimm_device_list.c
> @@ -5,3 +5,8 @@ int qmp_pc_dimm_device_list(Object *obj, void *opaque)
>  {
>     return 0;
>  }
> +
> +ram_addr_t get_current_ram_size(void)
> +{
> +    return ram_size;
> +}