Re: [XEN PATCH v1 1/1] Invalidate cache for cpus affinitized to the domain

[Jan Beulich <jbeulich@xxxxxxxx>]

On 11.12.2020 12:44, Harsha Shamsundara Havanur wrote:
> A HVM domain flushes cache on all the cpus using
> `flush_all` macro which uses cpu_online_map, during
> i) creation of a new domain
> ii) when device-model op is performed
> iii) when domain is destructed.
> 
> This triggers IPI on all the cpus, thus affecting other
> domains that are pinned to different pcpus. This patch
> restricts cache flush to the set of cpus affinitized to
> the current domain using `domain->dirty_cpumask`.

But then you need to effect cache flushing when a CPU gets
taken out of domain->dirty_cpumask. I don't think you/we want
to do that.

Jan