kvm: Prepare to add generic guest entry/exit callbacks
Do some ground preparatory work before adding guest_enter()
and guest_exit() context tracking callbacks. Those will
be later used to read the guest cputime safely when we
run in full dynticks mode.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/ia64/kernel/time.c b/arch/ia64/kernel/time.c
index a3a3f5a..fbaac1a 100644
--- a/arch/ia64/kernel/time.c
+++ b/arch/ia64/kernel/time.c
@@ -136,6 +136,7 @@
account_system_time(tsk, 0, delta, delta);
}
+EXPORT_SYMBOL_GPL(vtime_account_system);
void vtime_account_idle(struct task_struct *tsk)
{
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 22c9b67..2e04b37 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -347,6 +347,7 @@
if (stolen)
account_steal_time(stolen);
}
+EXPORT_SYMBOL_GPL(vtime_account_system);
void vtime_account_idle(struct task_struct *tsk)
{
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 2c497ab..4fe2396 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -22,6 +22,7 @@
#include <linux/rcupdate.h>
#include <linux/ratelimit.h>
#include <linux/err.h>
+#include <linux/irqflags.h>
#include <asm/signal.h>
#include <linux/kvm.h>
@@ -740,15 +741,36 @@
}
#endif /* CONFIG_IOMMU_API */
-static inline void kvm_guest_enter(void)
+static inline void guest_enter(void)
{
- BUG_ON(preemptible());
/*
* This is running in ioctl context so we can avoid
* the call to vtime_account() with its unnecessary idle check.
*/
- vtime_account_system_irqsafe(current);
+ vtime_account_system(current);
current->flags |= PF_VCPU;
+}
+
+static inline void guest_exit(void)
+{
+ /*
+ * This is running in ioctl context so we can avoid
+ * the call to vtime_account() with its unnecessary idle check.
+ */
+ vtime_account_system(current);
+ current->flags &= ~PF_VCPU;
+}
+
+static inline void kvm_guest_enter(void)
+{
+ unsigned long flags;
+
+ BUG_ON(preemptible());
+
+ local_irq_save(flags);
+ guest_enter();
+ local_irq_restore(flags);
+
/* 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 userspase from rcu point of view. In
@@ -761,12 +783,11 @@
static inline void kvm_guest_exit(void)
{
- /*
- * This is running in ioctl context so we can avoid
- * the call to vtime_account() with its unnecessary idle check.
- */
- vtime_account_system_irqsafe(current);
- current->flags &= ~PF_VCPU;
+ unsigned long flags;
+
+ local_irq_save(flags);
+ guest_exit();
+ local_irq_restore(flags);
}
/*
diff --git a/include/linux/vtime.h b/include/linux/vtime.h
index 5368af9..bb50c3c 100644
--- a/include/linux/vtime.h
+++ b/include/linux/vtime.h
@@ -6,7 +6,6 @@
#ifdef CONFIG_VIRT_CPU_ACCOUNTING
extern void vtime_task_switch(struct task_struct *prev);
extern void vtime_account_system(struct task_struct *tsk);
-extern void vtime_account_system_irqsafe(struct task_struct *tsk);
extern void vtime_account_idle(struct task_struct *tsk);
extern void vtime_account_user(struct task_struct *tsk);
extern void vtime_account(struct task_struct *tsk);
@@ -20,7 +19,6 @@
#else /* !CONFIG_VIRT_CPU_ACCOUNTING */
static inline void vtime_task_switch(struct task_struct *prev) { }
static inline void vtime_account_system(struct task_struct *tsk) { }
-static inline void vtime_account_system_irqsafe(struct task_struct *tsk) { }
static inline void vtime_account_user(struct task_struct *tsk) { }
static inline void vtime_account(struct task_struct *tsk) { }
static inline bool vtime_accounting_enabled(void) { return false; }
diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index c533dea..a44ecdf 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -465,16 +465,6 @@
*st = cputime.stime;
}
-void vtime_account_system_irqsafe(struct task_struct *tsk)
-{
- unsigned long flags;
-
- local_irq_save(flags);
- vtime_account_system(tsk);
- local_irq_restore(flags);
-}
-EXPORT_SYMBOL_GPL(vtime_account_system_irqsafe);
-
#ifndef __ARCH_HAS_VTIME_TASK_SWITCH
void vtime_task_switch(struct task_struct *prev)
{
