Re: [PATCH] xen/domain: Introduce vcpu_teardown()

[Jan Beulich <jbeulich@xxxxxxxx>]

On 19.01.2021 01:32, Andrew Cooper wrote:
> Similarly to c/s 98d4d6d8a6 "xen/domain: Introduce domain_teardown()",
> introduce a common mechanism for restartable per-vcpu teardown logic.
> 
> Extend the PROGRESS() mechanism to support saving and restoring the vcpu loop
> variable across hypercalls.
> 
> This will eventually supersede domain_reliquish_resources(), and reduce the
> quantity of redundant logic performed.
> 
> No functional change (yet).
> 
> Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>

Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
albeit perhaps with a name or type change:

> --- a/xen/include/xen/sched.h
> +++ b/xen/include/xen/sched.h
> @@ -532,6 +532,7 @@ struct domain
>       */
>      struct {
>          unsigned int val;
> +        struct vcpu *ptr;
>      } teardown;

I think the field either wants to be generic (and then of type void *)
or specific (and then be named "vcpu"). Which one is better certainly
depends on possibly anticipated future usage.

Jan