Re: [PATCH v2] target/ppc: Return default CPU for max CPU

[Daniel Henrique Barboza]

On 6/28/22 17:55, Murilo Opsfelder Araujo wrote:
> All ppc CPUs represent hardware that exists in the real world, i.e.: we
> do not have a "max" CPU with all possible emulated features enabled.
> Return the default CPU type for the machine because that has greater
> chance of being useful as the "max" CPU.
>
> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1038
> Cc: Cédric Le Goater <clg@kaod.org>
> Cc: Daniel Henrique Barboza <danielhb413@gmail.com>
> Cc: Daniel P. Berrangé <berrange@redhat.com>
> Cc: Greg Kurz <groug@kaod.org>
> Cc: Matheus K. Ferst <matheus.ferst@eldorado.org.br>
> Cc: Thomas Huth <thuth@redhat.com>
> Signed-off-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
> Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com>
> ---

Queued in gitlab.com/danielhb/qemu/tree/ppc-next. Thanks,


Daniel

> v2:
> - Return the default CPU of the machine instead of hard-coded alias.
>
> v1: 
> https://lore.kernel.org/qemu-devel/20220531172711.94564-1-muriloo@linux.ibm.com/
>
>   target/ppc/cpu-models.c |  1 -
>   target/ppc/cpu_init.c   | 19 +++++++++++++++++++
>   2 files changed, 19 insertions(+), 1 deletion(-)
>
> diff --git a/target/ppc/cpu-models.c b/target/ppc/cpu-models.c
> index 976be5e0d1..05589eb21d 100644
> --- a/target/ppc/cpu-models.c
> +++ b/target/ppc/cpu-models.c
> @@ -879,7 +879,6 @@ PowerPCCPUAlias ppc_cpu_aliases[] = {
>       { "755", "755_v2.8" },
>       { "goldfinger", "755_v2.8" },
>       { "7400", "7400_v2.9" },
> -    { "max", "7400_v2.9" },
>       { "g4",  "7400_v2.9" },
>       { "7410", "7410_v1.4" },
>       { "nitro", "7410_v1.4" },
> diff --git a/target/ppc/cpu_init.c b/target/ppc/cpu_init.c
> index c16cb8dbe7..8ee0b7c785 100644
> --- a/target/ppc/cpu_init.c
> +++ b/target/ppc/cpu_init.c
> @@ -47,6 +47,10 @@
>   #include "spr_common.h"
>   #include "power8-pmu.h"
>   
> +#ifndef CONFIG_USER_ONLY
> +#include "hw/boards.h"
> +#endif
> +
>   /* #define PPC_DEBUG_SPR */
>   /* #define USE_APPLE_GDB */
>   
> @@ -6963,6 +6967,21 @@ static ObjectClass *ppc_cpu_class_by_name(const char *name)
>           }
>       }
>   
> +    /*
> +     * All ppc CPUs represent hardware that exists in the real world, i.e.: we
> +     * do not have a "max" CPU with all possible emulated features enabled.
> +     * Return the default CPU type for the machine because that has greater
> +     * chance of being useful as the "max" CPU.
> +     */
> +#if !defined(CONFIG_USER_ONLY)
> +    if (strcmp(name, "max") == 0) {
> +        MachineClass *mc = MACHINE_GET_CLASS(qdev_get_machine());
> +        if (mc) {
> +            return object_class_by_name(mc->default_cpu_type);
> +        }
> +    }
> +#endif
> +
>       cpu_model = g_ascii_strdown(name, -1);
>       p = ppc_cpu_lookup_alias(cpu_model);
>       if (p) {