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>
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

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);
}
/*