Re: [Xen-devel] [PATCH] x86: add platform hypercall to retrieve pCPU-s' family, model, and stepping

[Keir Fraser <keir@xxxxxxx>]

On 12/12/2011 15:32, "Jan Beulich" <JBeulich@xxxxxxxx> wrote:

> With the recent hotplug changes to the Xen part of the microcode
> loading, this allows the kernel driver to avoid unnecessary calls into
> the hypervisor during pCPU hot-enabling: Knowing that the hypervisor
> retains the data for already booted CPUs, only data for CPUs with a
> different signature needs to be passed down. Since the microcode
> loading code can be pretty verbose, avoiding to invoke it can make the
> log much easier to look at in case of problems.
> 
> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

Acked-by: Keir Fraser <keir@xxxxxxx>

> --- 2011-11-23.orig/xen/arch/x86/platform_hypercall.c 2011-12-01
> 12:06:55.000000000 +0100
> +++ 2011-11-23/xen/arch/x86/platform_hypercall.c 2011-12-09 17:39:04.000000000
> +0100
> @@ -469,6 +469,42 @@ ret_t do_platform_op(XEN_GUEST_HANDLE(xe
>      }
>      break;
>  
> +    case XENPF_get_cpu_version:
> +    {
> +        struct xenpf_pcpu_version *ver = &op->u.pcpu_version;
> +
> +        if ( !get_cpu_maps() )
> +        {
> +            ret = -EBUSY;
> +            break;
> +        }
> +
> +        if ( (ver->xen_cpuid >= nr_cpu_ids) || !cpu_online(ver->xen_cpuid) )
> +        {
> +            memset(ver->vendor_id, 0, sizeof(ver->vendor_id));
> +            ver->family = 0;
> +            ver->model = 0;
> +            ver->stepping = 0;
> +        }
> +        else
> +        {
> +            const struct cpuinfo_x86 *c = &cpu_data[ver->xen_cpuid];
> +
> +            memcpy(ver->vendor_id, c->x86_vendor_id, sizeof(ver->vendor_id));
> +            ver->family = c->x86;
> +            ver->model = c->x86_model;
> +            ver->stepping = c->x86_mask;
> +        }
> +
> +        ver->max_present = cpumask_last(&cpu_present_map);
> +
> +        put_cpu_maps();
> +
> +        if ( copy_field_to_guest(u_xenpf_op, op, u.pcpu_version) )
> +            ret = -EFAULT;
> +    }
> +    break;
> +
>      case XENPF_cpu_online:
>      {
>          int cpu = op->u.cpu_ol.cpuid;
> --- 2011-11-23.orig/xen/arch/x86/x86_64/platform_hypercall.c 2011-12-09
> 17:40:49.000000000 +0100
> +++ 2011-11-23/xen/arch/x86/x86_64/platform_hypercall.c 2011-12-01
> 16:04:28.000000000 +0100
> @@ -3,7 +3,7 @@
>   */
>  
>  #include <xen/config.h>
> -#include <xen/types.h>
> +#include <xen/lib.h>
>  #include <compat/platform.h>
>  
>  DEFINE_XEN_GUEST_HANDLE(compat_platform_op_t);
> @@ -26,8 +26,13 @@ DEFINE_XEN_GUEST_HANDLE(compat_platform_
>  #define xen_processor_power_t   compat_processor_power_t
>  #define set_cx_pminfo           compat_set_cx_pminfo
>  
> -#define xenpf_pcpuinfo compat_pf_pcpuinfo
> -#define xenpf_pcpuinfo_t compat_pf_pcpuinfo_t
> +#define xen_pf_pcpuinfo xenpf_pcpuinfo
> +CHECK_pf_pcpuinfo;
> +#undef xen_pf_pcpuinfo
> +
> +#define xen_pf_pcpu_version xenpf_pcpu_version
> +CHECK_pf_pcpu_version;
> +#undef xen_pf_pcpu_version
>  
>  #define xenpf_enter_acpi_sleep compat_pf_enter_acpi_sleep
>  
> --- 2011-11-23.orig/xen/include/public/platform.h 2011-12-09
> 17:40:49.000000000 +0100
> +++ 2011-11-23/xen/include/public/platform.h 2011-12-09 17:39:17.000000000
> +0100
> @@ -449,6 +449,21 @@ struct xenpf_pcpuinfo {
>  typedef struct xenpf_pcpuinfo xenpf_pcpuinfo_t;
>  DEFINE_XEN_GUEST_HANDLE(xenpf_pcpuinfo_t);
>  
> +#define XENPF_get_cpu_version 48
> +struct xenpf_pcpu_version {
> +    /* IN */
> +    uint32_t xen_cpuid;
> +    /* OUT */
> +    /* The maxium cpu_id that is present */
> +    uint32_t max_present;
> +    char vendor_id[12];
> +    uint32_t family;
> +    uint32_t model;
> +    uint32_t stepping;
> +};
> +typedef struct xenpf_pcpu_version xenpf_pcpu_version_t;
> +DEFINE_XEN_GUEST_HANDLE(xenpf_pcpu_version_t);
> +
>  #define XENPF_cpu_online    56
>  #define XENPF_cpu_offline   57
>  struct xenpf_cpu_ol
> @@ -492,6 +507,7 @@ struct xen_platform_op {
>          struct xenpf_getidletime       getidletime;
>          struct xenpf_set_processor_pminfo set_pminfo;
>          struct xenpf_pcpuinfo          pcpu_info;
> +        struct xenpf_pcpu_version      pcpu_version;
>          struct xenpf_cpu_ol            cpu_ol;
>          struct xenpf_cpu_hotadd        cpu_add;
>          struct xenpf_mem_hotadd        mem_add;
> --- 2011-11-23.orig/xen/include/xlat.lst 2011-12-09 17:40:49.000000000 +0100
> +++ 2011-11-23/xen/include/xlat.lst 2011-12-01 15:46:31.000000000 +0100
> @@ -72,6 +72,17 @@
>  ? physdev_restore_msi  physdev.h
>  ? physdev_set_iopl  physdev.h
>  ? physdev_setup_gsi  physdev.h
> +! pct_register   platform.h
> +! power_register   platform.h
> +? processor_csd   platform.h
> +! processor_cx   platform.h
> +! processor_flags   platform.h
> +! processor_performance  platform.h
> +! processor_power   platform.h
> +? processor_px   platform.h
> +! psd_package   platform.h
> +? xenpf_pcpuinfo   platform.h
> +? xenpf_pcpu_version  platform.h
>  ! sched_poll   sched.h
>  ? sched_remote_shutdown  sched.h
>  ? sched_shutdown   sched.h
> @@ -84,12 +95,3 @@
>  ! vcpu_set_singleshot_timer vcpu.h
>  ? xenoprof_init   xenoprof.h
>  ? xenoprof_passive  xenoprof.h
> -! power_register   platform.h
> -? processor_csd   platform.h
> -! processor_cx   platform.h
> -! processor_flags   platform.h
> -! processor_power   platform.h
> -! pct_register   platform.h
> -? processor_px   platform.h
> -! psd_package   platform.h
> -! processor_performance  platform.h
> 
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@xxxxxxxxxxxxxxxxxxx
> http://lists.xensource.com/xen-devel



_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel