Attachment 295029 Details for Bug 430938 – add vcpu lock/unlock functions

[patch] add vcpu lock/unlock functions

RHEL5.2_new_vcpu_lock_affinity.patch (text/plain), 4.51 KB, created by Bhavna Sarathy on 2008-02-15 18:41:20 UTC

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Creator: Bhavna Sarathy

Created: 2008-02-15 18:41:20 UTC

Size: 4.51 KB

patch

obsolete

>Resolves BZ 430938
>
>Introduce new vcpu_lock_affinity() and vcpu_unlock_affinity() helper
>functions for use by x86's continue_hypercall_on_cpu().
>
>This has two advantages:
>1. We can lock out ordinary vcpu_set_affinity() commands from dom0.
>2. We avoid the (in this case bogus) check for dom0_vcpus_pin.
>
>
>--- xen/include/xen/sched.h.lockorig	2008-02-06 16:31:14.000000000 -0500
>+++ xen/include/xen/sched.h	2008-02-06 16:32:09.000000000 -0500
>@@ -119,6 +119,8 @@ struct vcpu 
>     bool_t           defer_shutdown;
>     /* VCPU is paused following shutdown request (d->is_shutting_down)? */
>     bool_t           paused_for_shutdown;
>+    /* VCPU affinity is temporarily locked from controller changes? */
>+    bool_t           affinity_locked;
> 
>     unsigned long    pause_flags;
>     atomic_t         pause_count;
>@@ -476,6 +478,8 @@ void cpu_init(void);
> 
> void vcpu_force_reschedule(struct vcpu *v);
> int vcpu_set_affinity(struct vcpu *v, cpumask_t *affinity);
>+int vcpu_lock_affinity(struct vcpu *v, cpumask_t *affinity);
>+void vcpu_unlock_affinity(struct vcpu *v, cpumask_t *affinity);
> 
> void vcpu_runstate_get(struct vcpu *v, struct vcpu_runstate_info *runstate);
> 
>--- xen/arch/x86/domain.c.lockorig	2008-02-06 16:30:44.000000000 -0500
>+++ xen/arch/x86/domain.c	2008-02-06 16:35:27.000000000 -0500
>@@ -1355,6 +1355,7 @@ static void continue_hypercall_on_cpu_he
> {
>     struct cpu_user_regs *regs = guest_cpu_user_regs();
>     struct migrate_info *info = v->arch.continue_info;
>+    cpumask_t mask = info->saved_affinity;
> 
>     regs->eax = info->func(info->data);
> 
>@@ -1363,7 +1364,7 @@ static void continue_hypercall_on_cpu_he
> 
>     xfree(info);
> 
>-    vcpu_set_affinity(v, &v->cpu_affinity);
>+    vcpu_unlock_affinity(v, &mask);
>     schedule_tail(v);
> }
> 
>@@ -1371,7 +1372,6 @@ int continue_hypercall_on_cpu(int cpu, l
> {
>     struct vcpu *v = current;
>     struct migrate_info *info;
>-    cpumask_t mask = cpumask_of_cpu(cpu);
>     int rc;
> 
>     if ( cpu == smp_processor_id() )
>@@ -1384,12 +1384,12 @@ int continue_hypercall_on_cpu(int cpu, l
>     info->func = func;
>     info->data = data;
>     info->saved_schedule_tail = v->arch.schedule_tail;
>-    info->saved_affinity = v->cpu_affinity;
>+    info->saved_affinity = cpumask_of_cpu(cpu);
> 
>     v->arch.schedule_tail = continue_hypercall_on_cpu_helper;
>     v->arch.continue_info = info;
> 
>-    rc = vcpu_set_affinity(v, &mask);
>+    rc = vcpu_lock_affinity(v, &info->saved_affinity);
>     if ( rc )
>     {
>         v->arch.schedule_tail = info->saved_schedule_tail;
>--- xen/common/schedule.c.lockorig	2008-02-06 16:31:00.000000000 -0500
>+++ xen/common/schedule.c	2008-02-06 16:37:37.000000000 -0500
>@@ -264,12 +264,11 @@ void vcpu_force_reschedule(struct vcpu *
>     }
> }
> 
>-int vcpu_set_affinity(struct vcpu *v, cpumask_t *affinity)
>+static int __vcpu_set_affinity(
>+    struct vcpu *v, cpumask_t *affinity,
>+    bool_t old_lock_status, bool_t new_lock_status)
> {
>-    cpumask_t online_affinity;
>-
>-    if ( (v->domain->domain_id == 0) && opt_dom0_vcpus_pin )
>-        return -EINVAL;
>+    cpumask_t online_affinity, old_affinity;
> 
>     cpus_and(online_affinity, *affinity, cpu_online_map);
>     if ( cpus_empty(online_affinity) )
>@@ -277,7 +276,18 @@ int vcpu_set_affinity(struct vcpu *v, cp
> 
>     vcpu_schedule_lock_irq(v);
> 
>+    if ( v->affinity_locked != old_lock_status )
>+    {
>+        BUG_ON(!v->affinity_locked);
>+        vcpu_schedule_unlock_irq(v);
>+        return -EBUSY;
>+    }
>+
>+    v->affinity_locked = new_lock_status;
>+
>+    old_affinity = v->cpu_affinity;
>     v->cpu_affinity = *affinity;
>+    *affinity = old_affinity;
>     if ( !cpu_isset(v->processor, v->cpu_affinity) )
>         set_bit(_VPF_migrating, &v->pause_flags);
> 
>@@ -292,6 +302,31 @@ int vcpu_set_affinity(struct vcpu *v, cp
>     return 0;
> }
> 
>+int vcpu_set_affinity(struct vcpu *v, cpumask_t *affinity)
>+{
>+    if ( (v->domain->domain_id == 0) && opt_dom0_vcpus_pin )
>+        return -EINVAL;
>+    return __vcpu_set_affinity(v, affinity, 0, 0);
>+}
>+
>+int vcpu_lock_affinity(struct vcpu *v, cpumask_t *affinity)
>+{
>+    return __vcpu_set_affinity(v, affinity, 0, 1);
>+}
>+
>+void vcpu_unlock_affinity(struct vcpu *v, cpumask_t *affinity)
>+{
>+    cpumask_t online_affinity;
>+
>+    /* Do not fail if no CPU in old affinity mask is online. */
>+    cpus_and(online_affinity, *affinity, cpu_online_map);
>+    if ( cpus_empty(online_affinity) )
>+        *affinity = cpu_online_map;
>+
>+    if ( __vcpu_set_affinity(v, affinity, 1, 0) != 0 )
>+        BUG();
>+}
>+
> /* Block the currently-executing domain until a pertinent event occurs. */
> static long do_block(void)
> {

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