From 14296e0c447885d6c7b326e059fb528eb00526ed Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Tue, 4 May 2021 17:27:33 -0700 Subject: [PATCH] context_tracking: Consolidate guest enter/exit wrappers Consolidate the guest enter/exit wrappers, providing and tweaking stubs as needed. This will allow moving the wrappers under KVM without having to bleed #ifdefs into the soon-to-be KVM code. No functional change intended. Signed-off-by: Sean Christopherson Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20210505002735.1684165-7-seanjc@google.com --- include/linux/context_tracking.h | 65 ++++++++++++-------------------- 1 file changed, 24 insertions(+), 41 deletions(-) diff --git a/include/linux/context_tracking.h b/include/linux/context_tracking.h index 56c648bdbde8..aa58c2ac67ca 100644 --- a/include/linux/context_tracking.h +++ b/include/linux/context_tracking.h @@ -71,6 +71,19 @@ static inline void exception_exit(enum ctx_state prev_ctx) } } +static __always_inline bool context_tracking_guest_enter(void) +{ + if (context_tracking_enabled()) + __context_tracking_enter(CONTEXT_GUEST); + + return context_tracking_enabled_this_cpu(); +} + +static __always_inline void context_tracking_guest_exit(void) +{ + if (context_tracking_enabled()) + __context_tracking_exit(CONTEXT_GUEST); +} /** * ct_state() - return the current context tracking state if known @@ -92,6 +105,9 @@ static inline void user_exit_irqoff(void) { } static inline enum ctx_state exception_enter(void) { return 0; } static inline void exception_exit(enum ctx_state prev_ctx) { } static inline enum ctx_state ct_state(void) { return CONTEXT_DISABLED; } +static inline bool context_tracking_guest_enter(void) { return false; } +static inline void context_tracking_guest_exit(void) { } + #endif /* !CONFIG_CONTEXT_TRACKING */ #define CT_WARN_ON(cond) WARN_ON(context_tracking_enabled() && (cond)) @@ -102,74 +118,41 @@ extern void context_tracking_init(void); static inline void context_tracking_init(void) { } #endif /* CONFIG_CONTEXT_TRACKING_FORCE */ - -#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN /* must be called with irqs disabled */ static __always_inline void guest_enter_irqoff(void) { + /* + * This is running in ioctl context so its safe to assume that it's the + * stime pending cputime to flush. + */ instrumentation_begin(); - if (vtime_accounting_enabled_this_cpu()) - vtime_guest_enter(current); - else - current->flags |= PF_VCPU; + vtime_account_guest_enter(); instrumentation_end(); - if (context_tracking_enabled()) - __context_tracking_enter(CONTEXT_GUEST); - - /* KVM does not hold any references to rcu protected data when it + /* + * 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_enabled_this_cpu()) { + if (!context_tracking_guest_enter()) { instrumentation_begin(); rcu_virt_note_context_switch(smp_processor_id()); instrumentation_end(); } } -static __always_inline void context_tracking_guest_exit(void) -{ - if (context_tracking_enabled()) - __context_tracking_exit(CONTEXT_GUEST); -} - static __always_inline void guest_exit_irqoff(void) { context_tracking_guest_exit(); - instrumentation_begin(); - vtime_account_guest_exit(); - instrumentation_end(); -} - -#else -static __always_inline void guest_enter_irqoff(void) -{ - /* - * This is running in ioctl context so its safe - * to assume that it's the stime pending cputime - * to flush. - */ - instrumentation_begin(); - vtime_account_guest_enter(); - rcu_virt_note_context_switch(smp_processor_id()); - instrumentation_end(); -} - -static __always_inline void context_tracking_guest_exit(void) { } - -static __always_inline void guest_exit_irqoff(void) -{ instrumentation_begin(); /* Flush the guest cputime we spent on the guest */ vtime_account_guest_exit(); instrumentation_end(); } -#endif /* CONFIG_VIRT_CPU_ACCOUNTING_GEN */ static inline void guest_exit(void) { -- 2.20.1