Re: [PATCH v2 4/8] x86: dynamically attach/detach CQM service for a guest

[Andrew Cooper <andrew.cooper3@citrix.com>]

On 21/11/13 07:20, dongxiao.xu@intel.com wrote:
> From: Dongxiao Xu <dongxiao.xu@intel.com>
>
> Add hypervisor side support for dynamically attach and detach CQM
> services for a certain guest.
>
> Signed-off-by: Jiongxi Li <jiongxi.li@intel.com>
> Signed-off-by: Dongxiao Xu <dongxiao.xu@intel.com>
> ---
>  xen/arch/x86/domctl.c       |   40 ++++++++++++++++++++++++++++++++++++++++
>  xen/include/public/domctl.h |   14 ++++++++++++++
>  2 files changed, 54 insertions(+)
>
> diff --git a/xen/arch/x86/domctl.c b/xen/arch/x86/domctl.c
> index f7e4586..5ef21f9 100644
> --- a/xen/arch/x86/domctl.c
> +++ b/xen/arch/x86/domctl.c
> @@ -35,6 +35,7 @@
>  #include <asm/mem_sharing.h>
>  #include <asm/xstate.h>
>  #include <asm/debugger.h>
> +#include <asm/pqos.h>
>  
>  static int gdbsx_guest_mem_io(
>      domid_t domid, struct xen_domctl_gdbsx_memio *iop)
> @@ -1223,6 +1224,45 @@ long arch_do_domctl(
>      }
>      break;
>  
> +    case XEN_DOMCTL_attach_pqos:
> +    {
> +        if ( domctl->u.qos_res.flags & XEN_DOMCTL_ADF_pqos_cqm )
> +        {
> +            if ( !system_supports_cqm() )
> +                ret = -ENODEV;
> +            else if ( d->arch.pqos_cqm_rmid > 0 )
> +                ret = -EINVAL;

EEXISTS perhaps?

> +            else
> +            {
> +                ret = alloc_cqm_rmid(d);
> +                if ( ret < 0 )
> +                    ret = -EBUSY;

On reflection, EUSERS is probably more accurate here.

> +            }
> +        }
> +        else
> +            ret = -EINVAL;
> +    }
> +    break;
> +
> +    case XEN_DOMCTL_detach_pqos:
> +    {
> +        if ( domctl->u.qos_res.flags & XEN_DOMCTL_ADF_pqos_cqm )
> +        {
> +            if ( !system_supports_cqm() )
> +                ret = -ENODEV;
> +            else if ( d->arch.pqos_cqm_rmid > 0 )
> +            {
> +                free_cqm_rmid(d);
> +                ret = 0;
> +            }
> +            else
> +                ret = -EINVAL;
> +        }
> +        else
> +            ret = -EINVAL;
> +    }
> +    break;
> +
>      default:
>          ret = iommu_do_domctl(domctl, d, u_domctl);
>          break;
> diff --git a/xen/include/public/domctl.h b/xen/include/public/domctl.h
> index 47a850a..f5d7062 100644
> --- a/xen/include/public/domctl.h
> +++ b/xen/include/public/domctl.h
> @@ -872,6 +872,17 @@ struct xen_domctl_set_max_evtchn {
>  typedef struct xen_domctl_set_max_evtchn xen_domctl_set_max_evtchn_t;
>  DEFINE_XEN_GUEST_HANDLE(xen_domctl_set_max_evtchn_t);
>  
> +/* XEN_DOMCTL_attach_pqos */
> +/* XEN_DOMCTL_detach_pqos */
> +struct xen_domctl_qos_resource {
> + /* Attach or detach flag for cqm */
> +#define _XEN_DOMCTL_ADF_pqos_cqm      0
> +#define XEN_DOMCTL_ADF_pqos_cqm       (1U<<_XEN_DOMCTL_ADF_pqos_cqm)

Does the ADF help here?  My personal opinion is that it makes the
constants more confusing.

~Andrew

> +    uint32_t flags;
> +};
> +typedef struct xen_domctl_qos_resource xen_domctl_qos_resource_t;
> +DEFINE_XEN_GUEST_HANDLE(xen_domctl_qos_resource_t);
> +
>  struct xen_domctl {
>      uint32_t cmd;
>  #define XEN_DOMCTL_createdomain                   1
> @@ -941,6 +952,8 @@ struct xen_domctl {
>  #define XEN_DOMCTL_setnodeaffinity               68
>  #define XEN_DOMCTL_getnodeaffinity               69
>  #define XEN_DOMCTL_set_max_evtchn                70
> +#define XEN_DOMCTL_attach_pqos                   71
> +#define XEN_DOMCTL_detach_pqos                   72
>  #define XEN_DOMCTL_gdbsx_guestmemio            1000
>  #define XEN_DOMCTL_gdbsx_pausevcpu             1001
>  #define XEN_DOMCTL_gdbsx_unpausevcpu           1002
> @@ -1001,6 +1014,7 @@ struct xen_domctl {
>          struct xen_domctl_set_broken_page_p2m set_broken_page_p2m;
>          struct xen_domctl_gdbsx_pauseunp_vcpu gdbsx_pauseunp_vcpu;
>          struct xen_domctl_gdbsx_domstatus   gdbsx_domstatus;
> +        struct xen_domctl_qos_resource      qos_res;
>          uint8_t                             pad[128];
>      } u;
>  };