[tip: x86/entry] context_tracking: Make guest_enter/exit() .noinstr ready

From: tip-bot2 for Thomas Gleixner
Date: Tue May 19 2020 - 16:00:44 EST


The following commit has been merged into the x86/entry branch of tip:

Commit-ID: af1e56b78534c38bb0e0c712ca70e59f816b74e9
Gitweb: https://git.kernel.org/tip/af1e56b78534c38bb0e0c712ca70e59f816b74e9
Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate: Thu, 19 Mar 2020 14:53:56 +01:00
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Tue, 19 May 2020 15:47:21 +02:00

context_tracking: Make guest_enter/exit() .noinstr ready

Force inlining of the helpers and mark the instrumentable parts
accordingly.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Reviewed-by: Alexandre Chartre <alexandre.chartre@xxxxxxxxxx>
Acked-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Link: https://lkml.kernel.org/r/20200505134341.672545766@xxxxxxxxxxxxx


---
include/linux/context_tracking.h | 21 ++++++++++++++++-----
1 file changed, 16 insertions(+), 5 deletions(-)

diff --git a/include/linux/context_tracking.h b/include/linux/context_tracking.h
index 8150f5a..8cac62e 100644
--- a/include/linux/context_tracking.h
+++ b/include/linux/context_tracking.h
@@ -101,12 +101,14 @@ static inline void context_tracking_init(void) { }

#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
/* must be called with irqs disabled */
-static inline void guest_enter_irqoff(void)
+static __always_inline void guest_enter_irqoff(void)
{
+ instrumentation_begin();
if (vtime_accounting_enabled_this_cpu())
vtime_guest_enter(current);
else
current->flags |= PF_VCPU;
+ instrumentation_end();

if (context_tracking_enabled())
__context_tracking_enter(CONTEXT_GUEST);
@@ -118,39 +120,48 @@ static inline void guest_enter_irqoff(void)
* 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_enabled_this_cpu()) {
+ instrumentation_begin();
rcu_virt_note_context_switch(smp_processor_id());
+ instrumentation_end();
+ }
}

-static inline void guest_exit_irqoff(void)
+static __always_inline void guest_exit_irqoff(void)
{
if (context_tracking_enabled())
__context_tracking_exit(CONTEXT_GUEST);

+ instrumentation_begin();
if (vtime_accounting_enabled_this_cpu())
vtime_guest_exit(current);
else
current->flags &= ~PF_VCPU;
+ instrumentation_end();
}

#else
-static inline void guest_enter_irqoff(void)
+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_kernel(current);
current->flags |= PF_VCPU;
rcu_virt_note_context_switch(smp_processor_id());
+ instrumentation_end();
}

-static inline void guest_exit_irqoff(void)
+static __always_inline void guest_exit_irqoff(void)
{
+ instrumentation_begin();
/* Flush the guest cputime we spent on the guest */
vtime_account_kernel(current);
current->flags &= ~PF_VCPU;
+ instrumentation_end();
}
#endif /* CONFIG_VIRT_CPU_ACCOUNTING_GEN */