Re: [Xen-devel] [PATCH v8 2/8] xen/arm: Add functions of mapping between vCPUID and virtual affinity

[Ian Campbell <ian.campbell@xxxxxxxxxx>]

On Fri, 2015-06-12 at 16:32 +0800, Chen Baozi wrote:
> From: Chen Baozi <baozich@xxxxxxxxx>
> 
> GICv3 restricts that the maximum number of CPUs in affinity 0 (one
> cluster) is 16. (See the note of 'Bits[15:0]' in '5.7.29 ICC_SGI0R_EL1
> ICC_SGI1R_EL1 and ICC_ASGI1R_EL1, GICv3 Architecture Specification')
> That is to say the upper 4 bits of affinity 0 is unused. Current
> implementation considers that AFF0 is equal to vCPUID, which makes all
> vCPUs in one cluster, limiting its number to 16. If we would like to
> support more than 16 number of vCPU in one guest, we need to make use
> of AFF1. Considering the unused upper 4 bits, we need to create a pair
> of functions mapping the vCPUID and virtual affinity.
> 
> Signed-off-by: Chen Baozi <baozich@xxxxxxxxx>
> Reviewed-by: Julien Grall <julien.grall@xxxxxxxxxx>

Acked-by: Ian Campbell <ian.campbell@xxxxxxxxxx>



_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel