Re: [vNUMA v2][PATCH 2/8] public interface

[Andre Przywara <andre.przywara@amd.com>]

Dulloor wrote:
> Interface definition. Structure that will be shared with hvmloader (with HVMs)
> and directly with the VMs (with PV).
> 
> -dulloor
> 
> Signed-off-by : Dulloor <dulloor@gmail.com>
> 
> +struct xen_vnode_info {
> +    uint8_t mnode_id;  /* physical node vnode is allocated from */
> +    uint32_t start;    /* start of the vnode range (in pages) */
> +    uint32_t end;             /* end of the vnode range (in pages) */
> +};
Is there a particular reason you made the start and end members 32bit only?
This effectively limits the amount of memory to 16TB, which is not that
far from being used (if not larger NUMA machines already shipping with
this amount of memory).
So can you push these variables to 64 bits?
> +struct xen_domain_numa_info {
> +    uint8_t version;    /* Interface version */
> +    uint8_t type;       /* VM memory allocation scheme (see above) */
> +
> +    uint8_t nr_vcpus;
> +    uint8_t nr_vnodes;
The same for here. I'd like to see at least nr_vcpus to be prepared for 
more than 256 vCPUs.
Please keep in mind that if Dom0 is also NUMA aware, by default the 
whole host resources are first given to Dom0, so the NUMA info should 
not be restricted to the size of a typical guest only.

Regards,
Andre.

-- 
Andre Przywara
AMD-Operating System Research Center (OSRC), Dresden, Germany
Tel: +49 351 448-3567-12