diff options
Diffstat (limited to 'include/linux/context_tracking.h')
| -rw-r--r-- | include/linux/context_tracking.h | 38 |
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 |