Add self pause ability, which is required by vcpu0/dom0 when
running on a AP. This can''t be satisfied by existing interface,
since the new flag also serves as a sync point.
Signed-off-by Kevin Tian <kevin.tian@intel.com>
diff -r d5315422dbc8 xen/common/domain.c
--- a/xen/common/domain.c Mon May 14 18:35:31 2007 -0400
+++ b/xen/common/domain.c Mon May 14 20:21:04 2007 -0400
@@ -530,6 +530,17 @@ void vcpu_pause_nosync(struct vcpu *v)
vcpu_sleep_nosync(v);
}
+/* _VPF_need_sync serves not only as flag for sync pause, but also
+ * as hint for other cpu waiting for this pause.
+ */
+void vcpu_pause_self(void)
+{
+ struct vcpu *v = current;
+
+ set_bit(_VPF_need_sync, &v->pause_flags);
+ vcpu_pause_nosync(v);
+}
+
void vcpu_unpause(struct vcpu *v)
{
if ( atomic_dec_and_test(&v->pause_count) )
diff -r d5315422dbc8 xen/common/schedule.c
--- a/xen/common/schedule.c Mon May 14 18:35:31 2007 -0400
+++ b/xen/common/schedule.c Mon May 14 18:54:28 2007 -0400
@@ -691,6 +691,13 @@ void context_saved(struct vcpu *prev)
if ( unlikely(test_bit(_VPF_migrating, &prev->pause_flags)) )
vcpu_migrate(prev);
+
+ if ( unlikely(test_bit(_VPF_need_sync, &prev->pause_flags)) )
+ {
+ sync_vcpu_execstate(prev);
+ /* test and clear can be split, since here is the only clear
point */
+ clear_bit(_VPF_need_sync, &prev->pause_flags);
+ }
}
/* The scheduler timer: force a run through the scheduler */
diff -r d5315422dbc8 xen/include/xen/sched.h
--- a/xen/include/xen/sched.h Mon May 14 18:35:31 2007 -0400
+++ b/xen/include/xen/sched.h Mon May 14 20:21:30 2007 -0400
@@ -457,6 +457,9 @@ extern struct domain *domain_list;
/* VCPU affinity has changed: migrating to a new CPU. */
#define _VPF_migrating 3
#define VPF_migrating (1UL<<_VPF_migrating)
+ /* VCPU needs full context sync once switched out */
+#define _VPF_need_sync 4
+#define VPF_need_sync (1UL<<_VPF_need_sync)
static inline int vcpu_runnable(struct vcpu *v)
{
@@ -467,6 +470,7 @@ static inline int vcpu_runnable(struct v
void vcpu_pause(struct vcpu *v);
void vcpu_pause_nosync(struct vcpu *v);
+void vcpu_pause_self(void);
void domain_pause(struct domain *d);
void vcpu_unpause(struct vcpu *v);
void domain_unpause(struct domain *d);
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