From c11f11fcbdb5be790c565aed46411486a7586afc Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Mon, 21 Jan 2013 00:50:22 +0100 Subject: [PATCH] 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 Cc: Andrew Morton Cc: Gleb Natapov Cc: Ingo Molnar Cc: Li Zhong Cc: Marcelo Tosatti Cc: Namhyung Kim Cc: Paul E. McKenney Cc: Paul Gortmaker Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Thomas Gleixner --- arch/ia64/kernel/time.c | 1 + arch/powerpc/kernel/time.c | 1 + include/linux/kvm_host.h | 39 +++++++++++++++++++++++++++++--------- include/linux/vtime.h | 2 -- kernel/sched/cputime.c | 10 ---------- 5 files changed, 32 insertions(+), 21 deletions(-) diff --git a/arch/ia64/kernel/time.c b/arch/ia64/kernel/time.c index a3a3f5a1cb3a..fbaac1afb844 100644 --- a/arch/ia64/kernel/time.c +++ b/arch/ia64/kernel/time.c @@ -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) { diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c index 22c9b67f9983..2e04b37f67f9 100644 --- a/arch/powerpc/kernel/time.c +++ b/arch/powerpc/kernel/time.c @@ -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) { diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 2c497ab0d03d..4fe2396401da 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -22,6 +22,7 @@ #include #include #include +#include #include #include @@ -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); } /* diff --git a/include/linux/vtime.h b/include/linux/vtime.h index 5368af9bdf06..bb50c3ca0d79 100644 --- a/include/linux/vtime.h +++ b/include/linux/vtime.h @@ -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; } diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c index c533deaf06d5..a44ecdf809a1 100644 --- a/kernel/sched/cputime.c +++ b/kernel/sched/cputime.c @@ -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) { -- 2.20.1