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kvm: Prepare to add generic guest entry/exit callbacks

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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>
This commit is contained in:
Frederic Weisbecker 2013-01-21 00:50:22 +01:00
parent 6fac4829ce
commit c11f11fcbd
5 changed files with 32 additions and 21 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

1
arch/ia64/kernel/time.c
View file

@ -136,6 +136,7 @@ void vtime_account_system(struct task_struct *tsk)
account_system_time(tsk, 0, delta, delta);
}
EXPORT_SYMBOL_GPL(vtime_account_system);
void vtime_account_idle(struct task_struct *tsk)
{

1
arch/powerpc/kernel/time.c
View file

@ -347,6 +347,7 @@ void vtime_account_system(struct task_struct *tsk)
if (stolen)
account_steal_time(stolen);
}
EXPORT_SYMBOL_GPL(vtime_account_system);
void vtime_account_idle(struct task_struct *tsk)
{

39
include/linux/kvm_host.h
View file

@ -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 @@ static inline int kvm_deassign_device(struct kvm *kvm,
}
#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_enter(void)
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);
}
/*

2
include/linux/vtime.h
View file

@ -6,7 +6,6 @@ struct task_struct;
#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 @@ static inline bool vtime_accounting_enabled(void) { return true; }
#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; }

10
kernel/sched/cputime.c
View file

@ -465,16 +465,6 @@ void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime
*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)
{