Re: [Qemu-devel] [PATCH v2] Introduce machine specific default memory size

[Igor Mammedov]

On Wed,  4 Mar 2015 16:48:05 +0530
Nikunj A Dadhania <address@hidden> wrote:

> QEMU default memory of 128MB is not enough to boot sPAPR
> guest. Introduce a member in the machine class to override the default
> memory size enforced by QEMU.
> 
now we have DEFAULT_RAM_SIZE in vl.c and default_ram_size in Machine class.
it is confusing.

Could you make current ram_size in vl.c a property of Machine
with default DEFAULT_RAM_SIZE moved there for generic Machine class
and do what you are doing here in property setter. Then it will work
for all machines the same way.

I'd actually suggest to take set_memory_options() and make
ram_size, slots, maxmem a properties of Machine and remap
-m parsing to normal machine option parsing. Getting rid of
global ram_size along the way.


> Signed-off-by: Nikunj A Dadhania <address@hidden>
> ---
>  hw/ppc/spapr.c         | 1 +
>  include/hw/boards.h    | 1 +
>  include/hw/ppc/spapr.h | 3 +++
>  vl.c                   | 9 +++++++++
>  4 files changed, 14 insertions(+)
> 
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index 23cde20..f6b1137 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -1738,6 +1738,7 @@ static void spapr_machine_class_init(ObjectClass *oc, 
> void *data)
>      mc->max_cpus = MAX_CPUS;
>      mc->no_parallel = 1;
>      mc->default_boot_order = NULL;
> +    mc->default_ram_size = SPAPR_DEFAULT_RAM_SIZE;
>      mc->kvm_type = spapr_kvm_type;
>      mc->has_dynamic_sysbus = true;
>  
> diff --git a/include/hw/boards.h b/include/hw/boards.h
> index 3ddc449..b2b4698 100644
> --- a/include/hw/boards.h
> +++ b/include/hw/boards.h
> @@ -108,6 +108,7 @@ struct MachineClass {
>      const char *default_display;
>      GlobalProperty *compat_props;
>      const char *hw_version;
> +    ram_addr_t default_ram_size;
>  
>      HotplugHandler *(*get_hotplug_handler)(MachineState *machine,
>                                             DeviceState *dev);
> diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
> index 716bff4..d401dd0 100644
> --- a/include/hw/ppc/spapr.h
> +++ b/include/hw/ppc/spapr.h
> @@ -444,6 +444,9 @@ int spapr_rtas_device_tree_setup(void *fdt, hwaddr 
> rtas_addr,
>  #define SPAPR_VIO_BASE_LIOBN    0x00000000
>  #define SPAPR_PCI_BASE_LIOBN    0x80000000
>  
> +/* Default to 1GB guest ram_size */
> +#define SPAPR_DEFAULT_RAM_SIZE  (1ULL << 30)
> +
>  #define RTAS_ERROR_LOG_MAX      2048
>  
>  typedef struct sPAPRTCETable sPAPRTCETable;
> diff --git a/vl.c b/vl.c
> index 801d487..447b993 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -2649,6 +2649,7 @@ static void set_memory_options(uint64_t *ram_slots, 
> ram_addr_t *maxram_size)
>      const ram_addr_t default_ram_size = (ram_addr_t)DEFAULT_RAM_SIZE *
>                                          1024 * 1024;
>      QemuOpts *opts = qemu_find_opts_singleton("memory");
> +    MachineClass *machine_class;
>  
>      sz = 0;
>      mem_str = qemu_opt_get(opts, "size");
> @@ -2684,6 +2685,14 @@ static void set_memory_options(uint64_t *ram_slots, 
> ram_addr_t *maxram_size)
>          exit(EXIT_FAILURE);
>      }
>  
> +    machine_class = find_default_machine();
> +    if (machine_class->default_ram_size && ram_size < 
> machine_class->default_ram_size) {
> +        fprintf(stderr, "qemu: %s guest ram size defaulting to %ld MB\n",
> +                machine_class->name,
> +                machine_class->default_ram_size / (1024 * 1024));
> +        ram_size = machine_class->default_ram_size;
> +    }
> +
>      /* store value for the future use */
>      qemu_opt_set_number(opts, "size", ram_size, &error_abort);
>      *maxram_size = ram_size;