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Diffstat (limited to 'include/linux/context_tracking.h')
-rw-r--r--include/linux/context_tracking.h38
1 files changed, 34 insertions, 4 deletions
diff --git a/include/linux/context_tracking.h b/include/linux/context_tracking.h
index d9aef2a0ec8e..c78fc27418f2 100644
--- a/include/linux/context_tracking.h
+++ b/include/linux/context_tracking.h
@@ -99,7 +99,8 @@ static inline void context_tracking_init(void) { }
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
-static inline void guest_enter(void)
+/* must be called with irqs disabled */
+static inline void guest_enter_irqoff(void)
{
if (vtime_accounting_cpu_enabled())
vtime_guest_enter(current);
@@ -108,9 +109,19 @@ static inline void guest_enter(void)
if (context_tracking_is_enabled())
__context_tracking_enter(CONTEXT_GUEST);
+
+ /* KVM does not hold any references to rcu protected data when it
+ * switches CPU into a guest mode. In fact switching to a guest mode
+ * is very similar to exiting to userspace from rcu point of view. In
+ * addition CPU may stay in a guest mode for quite a long time (up to
+ * one time slice). Lets treat guest mode as quiescent state, just like
+ * we do with user-mode execution.
+ */
+ if (!context_tracking_cpu_is_enabled())
+ rcu_virt_note_context_switch(smp_processor_id());
}
-static inline void guest_exit(void)
+static inline void guest_exit_irqoff(void)
{
if (context_tracking_is_enabled())
__context_tracking_exit(CONTEXT_GUEST);
@@ -122,7 +133,7 @@ static inline void guest_exit(void)
}
#else
-static inline void guest_enter(void)
+static inline void guest_enter_irqoff(void)
{
/*
* This is running in ioctl context so its safe
@@ -131,9 +142,10 @@ static inline void guest_enter(void)
*/
vtime_account_system(current);
current->flags |= PF_VCPU;
+ rcu_virt_note_context_switch(smp_processor_id());
}
-static inline void guest_exit(void)
+static inline void guest_exit_irqoff(void)
{
/* Flush the guest cputime we spent on the guest */
vtime_account_system(current);
@@ -141,4 +153,22 @@ static inline void guest_exit(void)
}
#endif /* CONFIG_VIRT_CPU_ACCOUNTING_GEN */
+static inline void guest_enter(void)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ guest_enter_irqoff();
+ local_irq_restore(flags);
+}
+
+static inline void guest_exit(void)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ guest_exit_irqoff();
+ local_irq_restore(flags);
+}
+
#endif