Re: [PATCH linux 0/8] xen: pvhvm: support bootup on secondary vCPUs

[Vitaly Kuznetsov]

David Vrabel <david.vrabel@xxxxxxxxxx> writes:

> On 28/06/16 17:47, Vitaly Kuznetsov wrote:
>> It may happen that Xen's and Linux's ideas of vCPU id diverge. In
>> particular, when we crash on a secondary vCPU we may want to do kdump
>> and unlike plain kexec where we do migrate_to_reboot_cpu() we try booting
>> on the vCPU which crashed. This doesn't work very well for PVHVM guests as
>> we have a number of hypercalls where we pass vCPU id as a parameter. These
>> hypercalls either fail or do something unexpected. To solve the issue we
>> need to have a mapping between Linux's and Xen's vCPU ids.
>
> Could the soft-reboot hypercall (optionally) return on vcpu 0?
>

In theory, yes, I think we can re-arrange vCPUs inside the hypervisor so
Linux will get them in the natural order after soft reset.

-- 
  Vitaly