Re: [Qemu-ppc] [Qemu-devel] [PATCH] xics_kvm: cache already enabled vCPU ids

[Laurent Vivier]

On 17/05/2017 17:18, Laurent Vivier wrote:
> On 17/05/2017 16:38, Greg Kurz wrote:
>> Since commit a45863bda90d ("xics_kvm: Don't enable KVM_CAP_IRQ_XICS if
>> already enabled"), we were able to re-hotplug a vCPU that had been hot-
>> unplugged ealier, thanks to a boolean flag in ICPState that we set when
>> enabling KVM_CAP_IRQ_XICS.
>>
>> This could work because the lifecycle of all ICPState objects was the
>> same as the machine. Commit 5bc8d26de20c ("spapr: allocate the ICPState
>> object from under sPAPRCPUCore") broke this assumption and now we always
>> pass a freshly allocated ICPState object (ie, with the flag unset) to
>> icp_kvm_cpu_setup().
>>
>> This cause re-hotplug to fail with:
>>
>> Unable to connect CPU8 to kernel XICS: Device or resource busy
>>
>> Let's fix this by caching all the vCPU ids for which KVM_CAP_IRQ_XICS was
>> enabled. This also drops the now useless boolean flag from ICPState.
>>
>> Reported-by: Laurent Vivier <address@hidden>
>> Signed-off-by: Greg Kurz <address@hidden>
> 
> Tested-by: Laurent Vivier <address@hidden>

and:

Reviewed-by: Laurent Vivier <address@hidden>