Re: [PATCH v5 7/8] libxl/libxc: Move libxl_get_numainfo()'s hypercall buffer management to libxc

[Ian Campbell <ian.campbell@citrix.com>]

On Thu, 2015-03-19 at 17:54 -0400, Boris Ostrovsky wrote:
> diff --git a/tools/libxc/xc_misc.c b/tools/libxc/xc_misc.c
> index 411128e..607ae61 100644
> --- a/tools/libxc/xc_misc.c
> +++ b/tools/libxc/xc_misc.c
> @@ -209,22 +209,49 @@ out:
>      return ret;
>  }
>  
> -int xc_numainfo(xc_interface *xch,
> -                xc_numainfo_t *put_info)
> +int xc_numainfo(xc_interface *xch, unsigned *max_nodes,
> +                xc_meminfo_t *meminfo, uint32_t *distance)
>  {
>      int ret;
>      DECLARE_SYSCTL;
> +    DECLARE_HYPERCALL_BOUNCE(meminfo, *max_nodes * sizeof(*meminfo),
> +                             XC_HYPERCALL_BUFFER_BOUNCE_OUT);
> +    DECLARE_HYPERCALL_BOUNCE(distance,
> +                             *max_nodes * *max_nodes * sizeof(*distance),
> +                             XC_HYPERCALL_BUFFER_BOUNCE_OUT);
>  
> -    sysctl.cmd = XEN_SYSCTL_numainfo;
> +    if (meminfo && distance) {
> +        if ((ret = xc_hypercall_bounce_pre(xch, meminfo)))
> +            goto out;
> +        if ((ret = xc_hypercall_bounce_pre(xch, distance)))
> +            goto out;

Same comment about handling NULL as before.

In addition what if only one of meminfo and distance is NULL? Is that
valid or do you need a !!meminfo ^ !!distance check?

Rests looks ok.