Re: [PATCH v2 for Xen 4.6 2/4] libxc: enabling XL to set per-VCPU parameters of a domain for RTDS scheduler

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

On Mon, 2015-05-25 at 19:07 -0500, Chong Li wrote:
> Add xc_sched_rtds_vcpu_get/set functions to interact with Xen to get/set a domain's
> per-VCPU parameters.
> 
> Signed-off-by: Chong Li <chong.li@wustl.edu>
> Signed-off-by: Meng Xu <mengxu@cis.upenn.edu>
> Signed-off-by: Sisu Xi <xisisu@gmail.com>

It looks like there is still some discussion around the shape of the
underlying hypercall interface.

I think this is an ok wrapping of the interface as it is n the previous
patch, so if that goes ahead:
        Acked-by: Ian Campbell <ian.campbell@citrix.com>
        
Obviously if this needs to change due to changes in the underlying
interface then this won't apply.

One nit below.


> ---
>  tools/libxc/include/xenctrl.h |  9 ++++++++
>  tools/libxc/xc_rt.c           | 53 +++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 62 insertions(+)
> 
> diff --git a/tools/libxc/include/xenctrl.h b/tools/libxc/include/xenctrl.h
> index 6994c51..45cbf91 100644
> --- a/tools/libxc/include/xenctrl.h
> +++ b/tools/libxc/include/xenctrl.h
> @@ -892,6 +892,15 @@ int xc_sched_rtds_domain_get(xc_interface *xch,
>                              uint32_t domid,
>                              struct xen_domctl_sched_rtds *sdom);
>  
> +int xc_sched_rtds_vcpu_set(xc_interface *xch,
> +                            uint32_t domid,
> +                            struct xen_domctl_sched_rtds_params *sdom,
> +                            uint16_t num_vcpus);
> +int xc_sched_rtds_vcpu_get(xc_interface *xch,
> +                            uint32_t domid,
> +                            struct xen_domctl_sched_rtds_params *sdom,
> +                            uint16_t num_vcpus);
> +
>  int
>  xc_sched_arinc653_schedule_set(
>      xc_interface *xch,
> diff --git a/tools/libxc/xc_rt.c b/tools/libxc/xc_rt.c
> index b2d1cc5..42aea22 100644
> --- a/tools/libxc/xc_rt.c
> +++ b/tools/libxc/xc_rt.c
> @@ -63,3 +63,56 @@ int xc_sched_rtds_domain_get(xc_interface *xch,
>  
>      return rc;
>  }
> +
> +int xc_sched_rtds_vcpu_set(xc_interface *xch,
> +                           uint32_t domid,
> +                           struct xen_domctl_sched_rtds_params *sdom,
> +                           uint16_t num_vcpus)
> +{
> +    int rc;
> +    DECLARE_DOMCTL;
> +    DECLARE_HYPERCALL_BOUNCE(sdom, sizeof(*sdom) * num_vcpus,
> +            XC_HYPERCALL_BUFFER_BOUNCE_IN);

Blank line here please.

> +    if ( xc_hypercall_bounce_pre(xch, sdom) )
> +        return -1;
> +
> +    domctl.cmd = XEN_DOMCTL_scheduler_vcpu_op;
> +    domctl.domain = (domid_t) domid;
> +    domctl.u.scheduler_vcpu_op.sched_id = XEN_SCHEDULER_RTDS;
> +    domctl.u.scheduler_vcpu_op.cmd = XEN_DOMCTL_SCHEDOP_putvcpuinfo;
> +    domctl.u.scheduler_vcpu_op.u.rtds.nr_vcpus = num_vcpus;
> +    set_xen_guest_handle(domctl.u.scheduler_vcpu_op.u.rtds.vcpus, sdom);
> +
> +    rc = do_domctl(xch, &domctl);
> +
> +    xc_hypercall_bounce_post(xch, sdom);
> +
> +    return rc;
> +}
> +
> +int xc_sched_rtds_vcpu_get(xc_interface *xch,
> +                           uint32_t domid,
> +                           struct xen_domctl_sched_rtds_params *sdom,
> +                           uint16_t num_vcpus)
> +{
> +    int rc;
> +    DECLARE_DOMCTL;
> +    DECLARE_HYPERCALL_BOUNCE(sdom, sizeof(*sdom) * num_vcpus,
> +            XC_HYPERCALL_BUFFER_BOUNCE_OUT);
> +
> +    if ( xc_hypercall_bounce_pre(xch, sdom) )
> +        return -1;
> +
> +    domctl.cmd = XEN_DOMCTL_scheduler_vcpu_op;
> +    domctl.domain = (domid_t) domid;
> +    domctl.u.scheduler_vcpu_op.sched_id = XEN_SCHEDULER_RTDS;
> +    domctl.u.scheduler_vcpu_op.cmd = XEN_DOMCTL_SCHEDOP_getvcpuinfo;
> +    domctl.u.scheduler_vcpu_op.u.rtds.nr_vcpus=num_vcpus;
> +    set_xen_guest_handle(domctl.u.scheduler_vcpu_op.u.rtds.vcpus, sdom);
> +
> +    rc = do_domctl(xch, &domctl);
> +
> +    xc_hypercall_bounce_post(xch, sdom);
> +
> +    return rc;
> +}