Re: [PATCH 1/1] Xen ARINC 653 Scheduler

[George Dunlap <George.Dunlap@eu.citrix.com>]

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Kathy, thanks for your work on this.  Unfortunately, with the new cpupools
feature, your actual scheduler will need a little more modification before
it can be merged into -unstable.  Cpu pools carves up the cpus into several
"pools", each of which has independent schedulers.  This means that
schedulers need to make pointers to per-pool "global" structures, rather
than having global static structures.  It should be a fairly straightforward
transformation; you can see example transformations done on the credit and
sedf schedulers.  Let us know if you need any help.

 -George

On Fri, Apr 16, 2010 at 9:18 AM, Kathy Hadley
<Kathy.Hadley@dornerworks.com>wrote:

>  This patch adds an ARINC 653 scheduler to Xen.  This is a modification of
> an earlier patch ([Xen-devel] [PATCH 1/1] Xen ARINC653 scheduler).  In
> particular, it has been modified to use the new .adjust_global callback
> function, which was added in “[Xen-devel] [PATCH 1/1] Add .adjust_global
> callback”.
>
>
>
> Thanks and regards,
>
>
>
>
>
> [image: cid:image001.jpg@01CAD7E0.50E45D70]
>
> *Kathy Hadley
> *DornerWorks, Ltd.
> *Embedded Systems Engineering
>
> *3445 Lake Eastbrook Blvd SE
> Grand Rapids, MI  49546
>
> Direct: 616.389.6127
>
> Tel:      616.245.8369
>
> Fax:     616.245.8372
>
>
>
> Kathy.Hadley@DornerWorks.com
>
> www.DornerWorks.com <http://www.dornerworks.com/>
>
> [image: cid:image002.jpg@01CAD7E0.50E45D70]
>
> *Honored as one of the 2010 “Michigan 50 Companies to Watch”*
>
>
>
> diff -rupN a/tools/libxc/Makefile b/tools/libxc/Makefile
>
> --- a/tools/libxc/Makefile            2010-04-13 10:49:37.573793000 -0400
>
> +++ b/tools/libxc/Makefile         2010-04-14 17:49:26.952638000 -0400
>
> @@ -17,6 +17,7 @@ CTRL_SRCS-y       += xc_physdev.c
>
>  CTRL_SRCS-y       += xc_private.c
>
>  CTRL_SRCS-y       += xc_sedf.c
>
>  CTRL_SRCS-y       += xc_csched.c
>
> +CTRL_SRCS-y       += xc_arinc653.c
>
>  CTRL_SRCS-y       += xc_tbuf.c
>
>  CTRL_SRCS-y       += xc_pm.c
>
>  CTRL_SRCS-y       += xc_cpu_hotplug.c
>
> diff -rupN a/tools/libxc/xc_arinc653.c b/tools/libxc/xc_arinc653.c
>
> --- a/tools/libxc/xc_arinc653.c     1969-12-31 19:00:00.000000000 -0500
>
> +++ b/tools/libxc/xc_arinc653.c 2010-04-14 17:49:26.952638000 -0400
>
> @@ -0,0 +1,28 @@
>
>
> +/****************************************************************************
>
> + * (C) 2010 - DornerWorks, Ltd <DornerWorks.com>
>
> +
> ****************************************************************************
>
> + *
>
> + *        File: xc_arinc653.c
>
> + *      Author: Josh Holtrop <DornerWorks.com>
>
> + *
>
> + * Description: XC Interface to the ARINC 653 scheduler
>
> + *
>
> + */
>
> +
>
> +#include "xc_private.h"
>
> +
>
> +int
>
> +xc_sched_arinc653_sched_set(
>
> +    int xc_handle,
>
> +    xen_domctl_sched_arinc653_schedule_t * sched)
>
> +{
>
> +    DECLARE_DOMCTL;
>
> +
>
> +    domctl.cmd = XEN_DOMCTL_scheduler_op;
>
> +    domctl.domain = (domid_t) 0;
>
> +    domctl.u.scheduler_op.sched_id = XEN_SCHEDULER_ARINC653;
>
> +    domctl.u.scheduler_op.cmd = XEN_DOMCTL_SCHEDOP_put_global_info;
>
> +    set_xen_guest_handle(domctl.u.scheduler_op.u.arinc653.schedule,
> sched);
>
> +
>
> +    return do_domctl(xc_handle, &domctl);
>
> +}
>
> diff -rupN a/tools/libxc/xenctrl.h b/tools/libxc/xenctrl.h
>
> --- a/tools/libxc/xenctrl.h            2010-04-13 10:49:37.573793000 -0400
>
> +++ b/tools/libxc/xenctrl.h         2010-04-14 17:49:26.952638000 -0400
>
> @@ -476,6 +476,16 @@ int xc_sched_credit_domain_get(int xc_ha
>
>                                 struct xen_domctl_sched_credit *sdom);
>
>
>
>  /**
>
> + * This function sets the global ARINC 653 schedule.
>
> + *
>
> + * @parm xc_handle a handle to an open hypervisor interface
>
> + * @parm sched a pointer to the new ARINC 653 schedule
>
> + * return 0 on success
>
> + */
>
> +int xc_sched_arinc653_sched_set(int xc_handle,
>
> +                                xen_domctl_sched_arinc653_schedule_t *
> sched);
>
> +
>
> +/**
>
>   * This function sends a trigger to a domain.
>
>   *
>
>   * @parm xc_handle a handle to an open hypervisor interface
>
> diff -rupN a/xen/common/Makefile b/xen/common/Makefile
>
> --- a/xen/common/Makefile         2010-04-13 10:49:37.573793000 -0400
>
> +++ b/xen/common/Makefile     2010-04-13 13:00:31.651749000 -0400
>
> @@ -14,6 +14,7 @@ obj-y += page_alloc.o
>
>  obj-y += rangeset.o
>
>  obj-y += sched_credit.o
>
>  obj-y += sched_sedf.o
>
> +obj-y += sched_arinc653.o
>
>  obj-y += schedule.o
>
>  obj-y += shutdown.o
>
>  obj-y += softirq.o
>
> diff -rupN a/xen/common/sched_arinc653.c b/xen/common/sched_arinc653.c
>
> --- a/xen/common/sched_arinc653.c       1969-12-31 19:00:00.000000000 -0500
>
> +++ b/xen/common/sched_arinc653.c    2010-04-14 18:13:26.163404000 -0400
>
> @@ -0,0 +1,590 @@
>
> +/*
>
> + * File: sched_arinc653.c
>
> + * Copyright (c) 2010, DornerWorks, Ltd. <DornerWorks.com>
>
> + *
>
> + * Description:
>
> + *   This file provides an ARINC653-compatible scheduling algorithm
>
> + *   for use in Xen.
>
> + *
>
> + * This program is free software; you can redistribute it and/or modify it
>
> + * under the terms of the GNU General Public License as published by the
> Free
>
> + * software Foundation; either version 2 of the License, or (at your
> option)
>
> + * any later version.
>
> + *
>
> + * This program is distributed in the hope that it will be useful,
>
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
>
> + * See the GNU General Public License for more details.
>
> + */
>
> +
>
> +
>
>
> +/**************************************************************************
>
> + * Includes
> *
>
> +
> *************************************************************************/
>
> +#include <xen/lib.h>
>
> +#include <xen/sched.h>
>
> +#include <xen/sched-if.h>
>
> +#include <xen/timer.h>
>
> +#include <xen/softirq.h>
>
> +#include <xen/time.h>
>
> +#include <xen/errno.h>
>
> +#include <xen/list.h>
>
> +#include <public/domctl.h>          /* ARINC653_MAX_DOMAINS_PER_SCHEDULE
> */
>
> +#include <xen/guest_access.h>
>
> +
>
> +
>
>
> +/**************************************************************************
>
> + * Private Macros
> *
>
> +
> **************************************************************************/
>
> +
>
> +/**
>
> + * Retrieve the idle VCPU for a given physical CPU
>
> + */
>
> +#define IDLETASK(cpu)  ((struct vcpu *) per_cpu(schedule_data,
> (cpu)).idle)
>
> +
>
> +/**
>
> + * Return a pointer to the ARINC 653-specific scheduler data information
>
> + * associated with the given VCPU (vc)
>
> + */
>
> +#define AVCPU(vc) ((arinc653_vcpu_t *)(vc)->sched_priv)
>
> +
>
>
> +/**************************************************************************
>
> + * Private Type Definitions
> *
>
> +
> **************************************************************************/
>
> +
>
> +/**
>
> + * The sched_entry_t structure holds a single entry of the
>
> + * ARINC 653 schedule.
>
> + */
>
> +typedef struct sched_entry_s
>
> +{
>
> +    /* dom_handle holds the handle ("UUID") for the domain that this
>
> +     * schedule entry refers to. */
>
> +    xen_domain_handle_t dom_handle;
>
> +    /* vcpu_id holds the VCPU number for the VCPU that this schedule
>
> +     * entry refers to. */
>
> +    int                 vcpu_id;
>
> +    /* runtime holds the number of nanoseconds that the VCPU for this
>
> +     * schedule entry should be allowed to run per major frame. */
>
> +    s_time_t            runtime;
>
> +    /* vc holds a pointer to the Xen VCPU structure */
>
> +    struct vcpu *       vc;
>
> +} sched_entry_t;
>
> +
>
> +/**
>
> + * The arinc653_vcpu_t structure holds ARINC 653-scheduler-specific
>
> + * information for all non-idle VCPUs
>
> + */
>
> +typedef struct arinc653_vcpu_s
>
> +{
>
> +    /* vc points to Xen's struct vcpu so we can get to it from an
>
> +     * arinc653_vcpu_t pointer. */
>
> +    struct vcpu *       vc;
>
> +    /* awake holds whether the VCPU has been woken with vcpu_wake() */
>
> +    bool_t              awake;
>
> +    /* list holds the linked list information for the list this VCPU
>
> +     * is stored in */
>
> +    struct list_head    list;
>
> +} arinc653_vcpu_t;
>
> +
>
> +
>
>
> +/**************************************************************************
>
> + * Global Data
>                            *
>
> +
> **************************************************************************/
>
> +
>
> +/**
>
> + * This array holds the active ARINC 653 schedule.
>
> + *
>
> + * When the system tries to start a new VCPU, this schedule is scanned
>
> + * to look for a matching (handle, VCPU #) pair. If both the handle
> ("UUID")
>
> + * and VCPU number match, then the VCPU is allowed to run. Its run time
>
> + * (per major frame) is given in the third entry of the schedule.
>
> + */
>
> +static sched_entry_t arinc653_schedule[ARINC653_MAX_DOMAINS_PER_SCHEDULE]
> = {
>
> +    { "", 0, MILLISECS(10), NULL }
>
> +};
>
> +
>
> +/**
>
> + * This variable holds the number of entries that are valid in
>
> + * the arinc653_schedule table.
>
> + *
>
> + * This is not necessarily the same as the number of domains in the
>
> + * schedule. A domain could be listed multiple times within the schedule,
>
> + * or a domain with multiple VCPUs could have a different
>
> + * schedule entry for each VCPU.
>
> + *
>
> + * A value of 1 means that only 1 domain (Dom0) will initially be started.
>
> + */
>
> +static int num_schedule_entries = 1;
>
> +
>
> +/**
>
> + * arinc653_major_frame holds the major frame time for the ARINC 653
> schedule.
>
> + */
>
> +static s_time_t arinc653_major_frame = MILLISECS(10);
>
> +
>
> +/**
>
> + * next_major_frame holds the time that the next major frame starts
>
> + */
>
> +static s_time_t next_major_frame = 0;
>
> +
>
> +/**
>
> + * vcpu_list holds pointers to all Xen VCPU structures for iterating
> through
>
> + */
>
> +static LIST_HEAD(vcpu_list);
>
> +
>
>
> +/**************************************************************************
>
> + * Scheduler functions
> *
>
> +
> **************************************************************************/
>
> +
>
> +/**
>
> + * This function compares two domain handles.
>
> + *
>
> + * @param h1        Pointer to handle 1
>
> + * @param h2        Pointer to handle 2
>
> + *
>
> + * @return          <ul>
>
> + *                  <li> <0:  handle 1 is less than handle 2
>
> + *                  <li>  0:  handle 1 is equal to handle 2
>
> + *                  <li> >0:  handle 1 is greater than handle 2
>
> + *                  </ul>
>
> + */
>
> +static int dom_handle_cmp(const xen_domain_handle_t h1,
>
> +                          const xen_domain_handle_t h2)
>
> +{
>
> +    return memcmp(h1, h2, sizeof(xen_domain_handle_t));
>
> +} /* end dom_handle_cmp */
>
> +
>
> +/**
>
> + * This function searches the vcpu list to find a VCPU that matches
>
> + * the domain handle and VCPU ID specified.
>
> + *
>
> + * @param handle    Pointer to handler
>
> + * @param vcpu_id   VCPU ID
>
> + *
>
> + * @return          <ul>
>
> + *                  <li> Pointer to the matching VCPU if one is found
>
> + *                  <li> NULL otherwise
>
> + *                  </ul>
>
> + */
>
> +static struct vcpu * find_vcpu(xen_domain_handle_t handle, int vcpu_id)
>
> +{
>
> +    arinc653_vcpu_t * avcpu; /* loop index variable */
>
> +    struct vcpu * vc = NULL;
>
> +
>
> +    /* loop through the vcpu_list looking for the specified VCPU */
>
> +    list_for_each_entry(avcpu, &vcpu_list, list)
>
> +    {
>
> +        /* If the handles & VCPU IDs match, we've found a matching VCPU */
>
> +        if ((dom_handle_cmp(avcpu->vc->domain->handle, handle) == 0)
>
> +             && (vcpu_id == avcpu->vc->vcpu_id))
>
> +        {
>
> +            vc = avcpu->vc;
>
> +            /*
>
> +             * "break" statement used instead of loop control variable
> because
>
> +             * the macro used for this loop does not support using loop
> control
>
> +             * variables
>
> +             */
>
> +            break;
>
> +        }
>
> +    }
>
> +
>
> +    return vc;
>
> +} /* end find_vcpu */
>
> +
>
> +/**
>
> + * This function updates the pointer to the Xen VCPU structure for each
> entry in
>
> + * the ARINC 653 schedule.
>
> + *
>
> + * @param           <None>
>
> + * @return          <None>
>
> + */
>
> +static void update_schedule_vcpus(void)
>
> +{
>
> +    /* Loop through the number of entries in the schedule */
>
> +    for (int i = 0; i < num_schedule_entries; i++)
>
> +    {
>
> +        /* Update the pointer to the Xen VCPU structure for the current
> entry */
>
> +        arinc653_schedule[i].vc =
>
> +            find_vcpu(arinc653_schedule[i].dom_handle,
>
> +                      arinc653_schedule[i].vcpu_id);
>
> +    }
>
> +} /* end update_schedule_vcpus */
>
> +
>
> +/**
>
> + * This function is called by the arinc653_adjust_global scheduler
>
> + * callback function in response to a domain control hypercall with
>
> + * a scheduler operation.
>
> + *
>
> + * The parameter schedule is set to be the address of a local variable
> from
>
> + * within arinc653_adjust_global(), so it is guaranteed to not be NULL.
>
> + *
>
> + * @param schedule  Pointer to the new ARINC 653 schedule.
>
> + *
>
> + * @return          <ul>
>
> + *                  <li> 0 = success
>
> + *                  <li> !0 = error
>
> + *                  </ul>
>
> + */
>
> +static int arinc653_sched_set(xen_domctl_sched_arinc653_schedule_t *
> schedule)
>
> +{
>
> +    int ret = 0;
>
> +    s_time_t total_runtime = 0;
>
> +    bool_t found_dom0 = 0;
>
> +    const static xen_domain_handle_t dom0_handle = {0};
>
> +
>
> +    /* check for valid major frame and number of schedule entries */
>
> +    if ( (schedule->major_frame <= 0)
>
> +      || (schedule->num_sched_entries < 1)
>
> +      || (schedule->num_sched_entries > ARINC653_MAX_DOMAINS_PER_SCHEDULE)
> )
>
> +    {
>
> +        ret = -EINVAL;
>
> +    }
>
> +
>
> +    if (ret == 0)
>
> +    {
>
> +        for (int i = 0; i < schedule->num_sched_entries; i++)
>
> +        {
>
> +            /*
>
> +             * look for domain 0 handle - every schedule must contain
>
> +             * some time for domain 0 to run
>
> +             */
>
> +            if (dom_handle_cmp(schedule->sched_entries[i].dom_handle,
>
> +                               dom0_handle) == 0)
>
> +            {
>
> +                found_dom0 = 1;
>
> +            }
>
> +
>
> +            /* check for a valid VCPU ID and run time */
>
> +            if ( (schedule->sched_entries[i].vcpu_id < 0)
>
> +              || (schedule->sched_entries[i].runtime <= 0) )
>
> +            {
>
> +                ret = -EINVAL;
>
> +            }
>
> +            else
>
> +            {
>
> +                /* Add this entry's run time to total run time */
>
> +                total_runtime += schedule->sched_entries[i].runtime;
>
> +            }
>
> +        } /* end loop through schedule entries */
>
> +    }
>
> +
>
> +    if (ret == 0)
>
> +    {
>
> +        /* error if the schedule doesn't contain a slot for domain 0 */
>
> +        if (found_dom0 == 0)
>
> +        {
>
> +            ret = -EINVAL;
>
> +        }
>
> +    }
>
> +
>
> +    if (ret == 0)
>
> +    {
>
> +        /*
>
> +         * error if the major frame is not large enough to run all entries
>
> +         * as indicated by comparing the total run time to the major frame
>
> +         * length
>
> +         */
>
> +        if (total_runtime > schedule->major_frame)
>
> +        {
>
> +            ret = -EINVAL;
>
> +        }
>
> +    }
>
> +
>
> +    if (ret == 0)
>
> +    {
>
> +        /* copy the new schedule into place */
>
> +        num_schedule_entries = schedule->num_sched_entries;
>
> +        arinc653_major_frame = schedule->major_frame;
>
> +        for (int i = 0; i < num_schedule_entries; i++)
>
> +        {
>
> +            memcpy(arinc653_schedule[i].dom_handle,
>
> +                   schedule->sched_entries[i].dom_handle,
>
> +                   sizeof(arinc653_schedule[i].dom_handle));
>
> +            arinc653_schedule[i].vcpu_id =
> schedule->sched_entries[i].vcpu_id;
>
> +            arinc653_schedule[i].runtime =
> schedule->sched_entries[i].runtime;
>
> +        }
>
> +        update_schedule_vcpus();
>
> +
>
> +        /*
>
> +         * The newly-installed schedule takes effect immediately.
>
> +         * We do not even wait for the current major frame to expire.
>
> +         *
>
> +         * Signal a new major frame to begin. The next major frame
>
> +         * is set up by the do_schedule callback function when it
>
> +         * is next invoked.
>
> +         */
>
> +        next_major_frame = NOW();
>
> +    }
>
> +
>
> +    return ret;
>
> +} /* end arinc653_sched_set */
>
> +
>
> +/**
>
> + * Xen scheduler callback function to adjust global scheduling parameters
>
> + *
>
> + * @param op    Pointer to the domain control scheduler operation
> structure
>
> + *
>
> + * @return          <ul>
>
> + *                  <li> 0 for success
>
> + *                  <li> !0 if there is an error
>
> + *                  </ul>
>
> + */
>
> +static int arinc653_adjust_global(struct xen_domctl_scheduler_op * op)
>
> +{
>
> +    int ret = -1;
>
> +    xen_domctl_sched_arinc653_schedule_t new_sched;
>
> +
>
> +    if (op->cmd == XEN_DOMCTL_SCHEDOP_put_global_info)
>
> +    {
>
> +        if (copy_from_guest(&new_sched, op->u.arinc653.schedule, 1) != 0)
>
> +        {
>
> +            ret = -EFAULT;
>
> +        }
>
> +        else
>
> +        {
>
> +            ret = arinc653_sched_set(&new_sched);
>
> +        }
>
> +    }
>
> +
>
> +    return ret;
>
> +} /* end arinc653_adjust_global */
>
> +
>
> +/**
>
> + * Xen scheduler callback function to initialize a virtual CPU (VCPU).
>
> + *
>
> + * @param v         Pointer to the VCPU structure
>
> + *
>
> + * @return          <ul>
>
> + *                  <li> 0 if the VCPU is allowed to run
>
> + *                  <li> !0 if there is an error
>
> + *                  </ul>
>
> + */
>
> +static int arinc653_init_vcpu(struct vcpu * v)
>
> +{
>
> +    int ret = -1;
>
> +
>
> +    if (is_idle_vcpu(v))
>
> +    {
>
> +        /*
>
> +         * The idle VCPU is created by Xen to run when no domains
>
> +         * are runnable or require CPU time.
>
> +         * It is similar to an "idle task" or "halt loop" process
>
> +         * in an operating system.
>
> +         * We do not track any scheduler information for the idle VCPU.
>
> +         */
>
> +        v->sched_priv = NULL;
>
> +        ret = 0;
>
> +    }
>
> +    else
>
> +    {
>
> +        /*
>
> +         * Allocate memory for the ARINC 653-specific scheduler data
> information
>
> +         * associated with the given VCPU (vc).
>
> +         */
>
> +        v->sched_priv = xmalloc(arinc653_vcpu_t);
>
> +        if (AVCPU(v) != NULL)
>
> +        {
>
> +            /*
>
> +             * Initialize our ARINC 653 scheduler-specific information
>
> +             * for the VCPU.
>
> +             * The VCPU starts "asleep."
>
> +             * When Xen is ready for the VCPU to run, it will call
>
> +             * the vcpu_wake scheduler callback function and our
>
> +             * scheduler will mark the VCPU awake.
>
> +             */
>
> +            AVCPU(v)->vc = v;
>
> +            AVCPU(v)->awake = 0;
>
> +            list_add(&AVCPU(v)->list, &vcpu_list);
>
> +            ret = 0;
>
> +            update_schedule_vcpus();
>
> +        }
>
> +    }
>
> +
>
> +    return ret;
>
> +} /* end arinc653_init_vcpu */
>
> +
>
> +/**
>
> + * Xen scheduler callback function to remove a VCPU
>
> + *
>
> + * @param v         Pointer to the VCPU structure to remove
>
> + *
>
> + * @return          <None>
>
> + */
>
> +static void arinc653_destroy_vcpu(struct vcpu * v)
>
> +{
>
> +    if (AVCPU(v) != NULL)
>
> +    {
>
> +        /* remove the VCPU from whichever list it is on */
>
> +        list_del(&AVCPU(v)->list);
>
> +        /* free the arinc653_vcpu structure */
>
> +        xfree(AVCPU(v));
>
> +        update_schedule_vcpus();
>
> +    }
>
> +} /* end arinc653_destroy_vcpu */
>
> +
>
> +/**
>
> + * Xen scheduler callback function to select a VCPU to run.
>
> + * This is the main scheduler routine.
>
> + *
>
> + * @param t         Current time
>
> + *
>
> + * @return          Time slice and address of the VCPU structure for the
> chosen
>
> + *                  domain
>
> + */
>
> +static struct task_slice arinc653_do_schedule(s_time_t t)
>
> +{
>
> +    struct task_slice ret;                      /* hold the chosen domain
> */
>
> +    struct vcpu * new_task = NULL;
>
> +    static int sched_index = 0;
>
> +    static s_time_t last_major_frame;
>
> +    static s_time_t last_switch_time;
>
> +    static s_time_t next_switch_time;
>
> +
>
> +    if (t >= next_major_frame)
>
> +    {
>
> +        /* time to enter a new major frame
>
> +         * the first time this function is called, this will be true */
>
> +        sched_index = 0;
>
> +        last_major_frame = last_switch_time = t;
>
> +        next_major_frame = t + arinc653_major_frame;
>
> +    }
>
> +    else if (t >= next_switch_time)
>
> +    {
>
> +        /* time to switch to the next domain in this major frame */
>
> +        sched_index++;
>
> +        last_switch_time = next_switch_time;
>
> +    }
>
> +
>
> +    /*
>
> +     * If there are more domains to run in the current major frame, set
>
> +     * next_switch_time equal to the last switch time + this domain's run
> time.
>
> +     * Otherwise, set next_switch_time equal to the start of the next
> major
>
> +     * frame.
>
> +     */
>
> +    next_switch_time = (sched_index < num_schedule_entries)
>
> +                     ? last_switch_time +
> arinc653_schedule[sched_index].runtime
>
> +                     : next_major_frame;
>
> +
>
> +    /*
>
> +     * If there are more domains to run in the current major frame, set
>
> +     * new_task equal to the address of next domain's VCPU structure.
>
> +     * Otherwise, set new_task equal to the address of the idle task's
> VCPU
>
> +     * structure.
>
> +     */
>
> +    new_task = (sched_index < num_schedule_entries)
>
> +                   ? arinc653_schedule[sched_index].vc
>
> +                   : IDLETASK(0);
>
> +
>
> +    /* Check to see if the new task can be run (awake & runnable). */
>
> +    if (!((new_task != NULL)
>
> +            && AVCPU(new_task)->awake
>
> +            && vcpu_runnable(new_task)) )
>
> +    {
>
> +        new_task = IDLETASK(0);
>
> +    }
>
> +    BUG_ON(new_task == NULL);
>
> +
>
> +    /*
>
> +     * Check to make sure we did not miss a major frame.
>
> +     * This is a good test for robust partitioning.
>
> +     */
>
> +    BUG_ON(t >= next_major_frame);
>
> +
>
> +    /*
>
> +     * Return the amount of time the next domain has to run and the
> address
>
> +     * of the selected task's VCPU structure.
>
> +     */
>
> +    ret.time = next_switch_time - t;
>
> +    ret.task = new_task;
>
> +
>
> +    BUG_ON(ret.time <= 0);
>
> +
>
> +    return ret;
>
> +} /* end arinc653_do_schedule */
>
> +
>
> +/**
>
> + * Xen scheduler callback function to select a CPU for the VCPU to run on
>
> + *
>
> + * @param v         Pointer to the VCPU structure for the current domain
>
> + *
>
> + * @return          Number of selected physical CPU
>
> + */
>
> +static int arinc653_pick_cpu(struct vcpu * v)
>
> +{
>
> +    /* this implementation only supports one physical CPU */
>
> +    return 0;
>
> +} /* end arinc653_pick_cpu */
>
> +
>
> +/**
>
> + * Xen scheduler callback function to wake up a VCPU
>
> + *
>
> + * @param vc        Pointer to the VCPU structure for the current domain
>
> + *
>
> + * @return          <None>
>
> + */
>
> +static void arinc653_vcpu_wake(struct vcpu * vc)
>
> +{
>
> +    /* boolean flag to indicate first run */
>
> +    static bool_t dont_raise_softirq = 0;
>
> +
>
> +    if (AVCPU(vc) != NULL)  /* check that this is a VCPU we are tracking
> */
>
> +    {
>
> +        AVCPU(vc)->awake = 1;
>
> +    }
>
> +
>
> +    /* the first time the vcpu_wake function is called, we should raise
>
> +     * a softirq to invoke the do_scheduler callback */
>
> +    if (!dont_raise_softirq)
>
> +    {
>
> +        cpu_raise_softirq(vc->processor, SCHEDULE_SOFTIRQ);
>
> +        dont_raise_softirq = 1;
>
> +    }
>
> +} /* end arinc653_vcpu_wake */
>
> +
>
> +/**
>
> + * Xen scheduler callback function to sleep a VCPU
>
> + *
>
> + * @param vc        Pointer to the VCPU structure for the current domain
>
> + *
>
> + * @return          <None>
>
> + */
>
> +static void arinc653_vcpu_sleep(struct vcpu * vc)
>
> +{
>
> +    if (AVCPU(vc) != NULL)  /* check that this is a VCPU we are tracking
> */
>
> +    {
>
> +        AVCPU(vc)->awake = 0;
>
> +    }
>
> +
>
> +    /* if the VCPU being put to sleep is the same one that is currently
>
> +     * running, raise a softirq to invoke the scheduler to switch domains
> */
>
> +    if (per_cpu(schedule_data, vc->processor).curr == vc)
>
> +    {
>
> +        cpu_raise_softirq(vc->processor, SCHEDULE_SOFTIRQ);
>
> +    }
>
> +} /* end arinc653_vcpu_sleep */
>
> +
>
> +/**
>
> + * This structure defines our scheduler for Xen.
>
> + * The entries tell Xen where to find our scheduler-specific
>
> + * callback functions.
>
> + * The symbol must be visible to the rest of Xen at link time.
>
> + */
>
> +struct scheduler sched_arinc653_def = {
>
> +    .name           = "ARINC 653 Scheduler",
>
> +    .opt_name       = "arinc653",
>
> +    .sched_id       = XEN_SCHEDULER_ARINC653,
>
> +
>
> +    .init_domain    = NULL,
>
> +    .destroy_domain = NULL,
>
> +
>
> +    .init_vcpu      = arinc653_init_vcpu,
>
> +    .destroy_vcpu   = arinc653_destroy_vcpu,
>
> +
>
> +    .do_schedule    = arinc653_do_schedule,
>
> +    .pick_cpu       = arinc653_pick_cpu,
>
> +    .dump_cpu_state = NULL,
>
> +    .sleep          = arinc653_vcpu_sleep,
>
> +    .wake           = arinc653_vcpu_wake,
>
> +    .adjust         = NULL,
>
> +    .adjust_global  = arinc653_adjust_global,
>
> +};
>
> diff -rupN a/xen/common/schedule.c b/xen/common/schedule.c
>
> --- a/xen/common/schedule.c     2010-04-14 10:57:11.262796000 -0400
>
> +++ b/xen/common/schedule.c  2010-04-14 16:40:21.543608000 -0400
>
> @@ -7,7 +7,8 @@
>
>   *        File: common/schedule.c
>
>   *      Author: Rolf Neugebauer & Keir Fraser
>
>   *              Updated for generic API by Mark Williamson
>
> - *
>
> + *              ARINC653 scheduler added by DornerWorks <DornerWorks.com>
>
> + *
>
>   * Description: Generic CPU scheduling code
>
>   *              implements support functionality for the Xen scheduler
> API.
>
>   *
>
> @@ -56,9 +57,11 @@ DEFINE_PER_CPU(struct schedule_data, sch
>
>
>
>  extern const struct scheduler sched_sedf_def;
>
>  extern const struct scheduler sched_credit_def;
>
> +extern const struct scheduler sched_arinc653_def;
>
>  static const struct scheduler *__initdata schedulers[] = {
>
>      &sched_sedf_def,
>
>      &sched_credit_def,
>
> +    &sched_arinc653_def,
>
>      NULL
>
>  };
>
>
>
> diff -rupN a/xen/include/public/domctl.h b/xen/include/public/domctl.h
>
> --- a/xen/include/public/domctl.h 2010-04-14 10:57:11.262796000 -0400
>
> +++ b/xen/include/public/domctl.h         2010-04-14 16:40:21.543608000
> -0400
>
> @@ -23,6 +23,8 @@
>
>   *
>
>   * Copyright (c) 2002-2003, B Dragovic
>
>   * Copyright (c) 2002-2006, K Fraser
>
> + *
>
> + * ARINC653 Scheduler type added by DornerWorks <DornerWorks.com>.
>
>   */
>
>
>
>  #ifndef __XEN_PUBLIC_DOMCTL_H__
>
> @@ -303,11 +305,43 @@ DEFINE_XEN_GUEST_HANDLE(xen_domctl_max_v
>
>  /* Scheduler types. */
>
>  #define XEN_SCHEDULER_SEDF     4
>
>  #define XEN_SCHEDULER_CREDIT   5
>
> +#define XEN_SCHEDULER_ARINC653 6
>
> +
>
>  /* Set or get info? */
>
>  #define XEN_DOMCTL_SCHEDOP_putinfo 0
>
>  #define XEN_DOMCTL_SCHEDOP_getinfo 1
>
>  #define XEN_DOMCTL_SCHEDOP_put_global_info 2
>
>  #define XEN_DOMCTL_SCHEDOP_get_global_info 3
>
> +
>
> +/*
>
> + * This structure is used to pass a new ARINC653 schedule from a
>
> + * privileged domain (ie dom0) to Xen.
>
> + */
>
> +#define ARINC653_MAX_DOMAINS_PER_SCHEDULE   64
>
> +struct xen_domctl_sched_arinc653_schedule {
>
> +    /* major_frame holds the time for the new schedule's major frame
>
> +     * in nanoseconds. */
>
> +    int64_t     major_frame;
>
> +    /* num_sched_entries holds how many of the entries in the
>
> +     * sched_entries[] array are valid. */
>
> +    uint8_t     num_sched_entries;
>
> +    /* The sched_entries array holds the actual schedule entries. */
>
> +    struct {
>
> +        /* dom_handle must match a domain's UUID */
>
> +        xen_domain_handle_t dom_handle;
>
> +        /* If a domain has multiple VCPUs, vcpu_id specifies which one
>
> +         * this schedule entry applies to. It should be set to 0 if
>
> +         * there is only one VCPU for the domain. */
>
> +        int                 vcpu_id;
>
> +        /* runtime specifies the amount of time that should be allocated
>
> +         * to this VCPU per major frame. It is specified in nanoseconds */
>
> +        int64_t             runtime;
>
> +    } sched_entries[ARINC653_MAX_DOMAINS_PER_SCHEDULE];
>
> +};
>
> +typedef struct xen_domctl_sched_arinc653_schedule
>
> +    xen_domctl_sched_arinc653_schedule_t;
>
> +DEFINE_XEN_GUEST_HANDLE(xen_domctl_sched_arinc653_schedule_t);
>
> +
>
>  struct xen_domctl_scheduler_op {
>
>      uint32_t sched_id;  /* XEN_SCHEDULER_* */
>
>      uint32_t cmd;       /* XEN_DOMCTL_SCHEDOP_* */
>
> @@ -323,6 +357,9 @@ struct xen_domctl_scheduler_op {
>
>              uint16_t weight;
>
>              uint16_t cap;
>
>          } credit;
>
> +        struct xen_domctl_sched_arinc653 {
>
> +            XEN_GUEST_HANDLE(xen_domctl_sched_arinc653_schedule_t)
> schedule;
>
> +        } arinc653;
>
>      } u;
>
>  };
>
>  typedef struct xen_domctl_scheduler_op xen_domctl_scheduler_op_t;
>
>
>
>
>
>
>
>
>
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xensource.com
> http://lists.xensource.com/xen-devel
>
>

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