Re: [PATCH 02/16] xen/x86: Move freeze/thaw_domains into common files

[Jan Beulich <jbeulich@xxxxxxxx>]

On 05.03.2025 10:11, Mykola Kvach wrote:
> From: Mirela Simonovic <mirela.simonovic@xxxxxxxxxx>
> 
> These functions will be reused by suspend/resume support for ARM.

And until then they are going to violate the Misra rule requiring there
to not be unreachable code.

> --- a/xen/common/domain.c
> +++ b/xen/common/domain.c
> @@ -2259,6 +2259,36 @@ int continue_hypercall_on_cpu(
>      return 0;
>  }
>  
> +
> +void freeze_domains(void)

Nit: No double blank lines please.

> +{
> +    struct domain *d;
> +
> +    rcu_read_lock(&domlist_read_lock);
> +    /*
> +     * Note that we iterate in order of domain-id. Hence we will pause dom0
> +     * first which is required for correctness (as only dom0 can add domains 
> to
> +     * the domain list). Otherwise we could miss concurrently-created 
> domains.
> +     */
> +    for_each_domain ( d )
> +        domain_pause(d);
> +    rcu_read_unlock(&domlist_read_lock);
> +
> +    scheduler_disable();

When made generally available I'm unsure having this and ...

> +}
> +
> +void thaw_domains(void)
> +{
> +    struct domain *d;
> +
> +    scheduler_enable();

... this here is a good idea. Both scheduler operations aren't related
to what the function names say is being done here.

Jan