Re: [PATCH v2] hw/ppc/e500: Check for compatible CPU type instead of aborting ungracefully

[BALATON Zoltan <balaton@eik.bme.hu>]

On Wed, 15 Oct 2025, Thomas Huth wrote:
> From: Thomas Huth <thuth@redhat.com>
>
> When using the ppce500 machine with an embedded CPU type that has
> the right MMU model, but is not part of the e500 CPU family, QEMU
> currently aborts ungracefully:
>
> $ ./qemu-system-ppc -machine ppce500 -cpu e200z5 -nographic
> qemu-system-ppc: ../qemu/hw/core/gpio.c:108: qdev_get_gpio_in_named:
>  Assertion `n >= 0 && n < gpio_list->num_in' failed.
> Aborted (core dumped)
>
> The ppce500 machine expects a CPU with certain GPIO interrupt pins,
> so let's replace the coarse check for the MMU_BOOKE206 model with
> a more precise check that only allows CPUs from the e500 family.
>
> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/3162
> Signed-off-by: Thomas Huth <thuth@redhat.com>

Reviewed-by: BALATON Zoltan <balaton@eik.bme.hu>

> ---
> v2: Drop the old check for the MMU_BOOKE206 model
>
> hw/ppc/e500.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/hw/ppc/e500.c b/hw/ppc/e500.c
> index 723c97fad2e..3d69428f31c 100644
> --- a/hw/ppc/e500.c
> +++ b/hw/ppc/e500.c
> @@ -20,6 +20,7 @@
> #include "qemu/guest-random.h"
> #include "exec/target_page.h"
> #include "qapi/error.h"
> +#include "cpu-models.h"
> #include "e500.h"
> #include "e500-ccsr.h"
> #include "net/net.h"
> @@ -942,9 +943,8 @@ void ppce500_init(MachineState *machine)
>         env = &cpu->env;
>         cs = CPU(cpu);
>
> -        if (env->mmu_model != POWERPC_MMU_BOOKE206) {
> -            error_report("MMU model %i not supported by this machine",
> -                         env->mmu_model);
> +        if (!(POWERPC_CPU_GET_CLASS(cpu)->svr & POWERPC_SVR_E500)) {
> +            error_report("This machine needs a CPU from the e500 family");
>             exit(1);
>         }
>
>