On 21/02/2020 12:52, Xia, Hongyan wrote:
> On Fri, 2020-02-21 at 11:50 +0000, Wei Liu wrote:
>> Given that:
>>
>> 1. mapcache_domain is now a structure with only one member.
>> 2. ents is a constant throughout domain's lifecycle.
>>
>> You can replace mapcache_domain with a boolean --
>> mapcache_mapping_populated (?) in arch.pv.
>>
>> If I'm not mistaken, the size of the mapping is derived from the vcpu
>> being initialised, so a further improvement is to lift the mapping
>> creation out of mapcache_vcpu_init.
> But you can just XEN_DOMCTL_max_vcpus on a running domain to increase
> its max_vcpus count, so that ents is not constant?
The comments suggest that, but it has never been implemented, and I'm in
the process of purging the ability.
Already now, max is passed into domain_create, and the
XEN_DOMCTL_max_vcpus call has to exactly match what was passed to
create. As soon as the {domain,vcpu}_destroy() functions become
properly idempotent (so we can unwind from midway through after an
-ENOMEM/etc), XEN_DOMCTL_max_vcpus will be dropped completely.
d->max_cpus is set early during construction, and remains constant for
the lifetime of the domain.
~Andrew
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel
