Re: [PATCH] hw/arm/xlnx-zynqmp: fix unsigned error when checking the RPUs number

[Francisco Iglesias <frasse.iglesias@gmail.com>]

On [2023 May 24] Wed 16:37:14, Clément Chigot wrote:
> When passing --smp with a number lower than XLNX_ZYNQMP_NUM_APU_CPUS,
> the expression (ms->smp.cpus - XLNX_ZYNQMP_NUM_APU_CPUS) will result
> in a positive number as ms->smp.cpus is a unsigned int.
> This will raise the following error afterwards, as Qemu will try to
> instantiate some additional RPUs.
>   | $ qemu-system-aarch64 --smp 1 -M xlnx-zcu102
>   | **
>   | ERROR:../src/tcg/tcg.c:777:tcg_register_thread:
>   |   assertion failed: (n < tcg_max_ctxs)
> 
> Signed-off-by: Clément Chigot <chigot@adacore.com>

Reviewed-by: Francisco Iglesias <frasse.iglesias@gmail.com>
Tested-by: Francisco Iglesias <frasse.iglesias@gmail.com>

> ---
>  hw/arm/xlnx-zynqmp.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/hw/arm/xlnx-zynqmp.c b/hw/arm/xlnx-zynqmp.c
> index 335cfc417d..5905a33015 100644
> --- a/hw/arm/xlnx-zynqmp.c
> +++ b/hw/arm/xlnx-zynqmp.c
> @@ -213,7 +213,7 @@ static void xlnx_zynqmp_create_rpu(MachineState *ms, XlnxZynqMPState *s,
>                                     const char *boot_cpu, Error **errp)
>  {
>      int i;
> -    int num_rpus = MIN(ms->smp.cpus - XLNX_ZYNQMP_NUM_APU_CPUS,
> +    int num_rpus = MIN((int)(ms->smp.cpus - XLNX_ZYNQMP_NUM_APU_CPUS),
>                         XLNX_ZYNQMP_NUM_RPU_CPUS);
>  
>      if (num_rpus <= 0) {
> -- 
> 2.25.1
> 
>