[tip: x86/urgent] context_tracking: Move guest exit vtime accounting to separate helpers

[tip-bot2 for Wanpeng Li]

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

Commit-ID:     88d8220bbf06dd8045b2ac4be1046290eaa7773a
Gitweb:        https://git.kernel.org/tip/88d8220bbf06dd8045b2ac4be1046290eaa7773a
Author:        Wanpeng Li <wanpengli@xxxxxxxxxxx>
AuthorDate:    Tue, 04 May 2021 17:27:29 -07:00
Committer:     Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Wed, 05 May 2021 22:54:11 +02:00

context_tracking: Move guest exit vtime accounting to separate helpers

Provide separate vtime accounting functions for guest exit instead of
open coding the logic within the context tracking code.  This will allow
KVM x86 to handle vtime accounting slightly differently when using
tick-based accounting.

Suggested-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Wanpeng Li <wanpengli@xxxxxxxxxxx>
Co-developed-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Reviewed-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20210505002735.1684165-3-seanjc@xxxxxxxxxx

---
 include/linux/context_tracking.h | 22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/include/linux/context_tracking.h b/include/linux/context_tracking.h
index b8c7313..4f45562 100644
--- a/include/linux/context_tracking.h
+++ b/include/linux/context_tracking.h
@@ -137,15 +137,20 @@ static __always_inline void context_tracking_guest_exit(void)
 		__context_tracking_exit(CONTEXT_GUEST);
 }
 
-static __always_inline void guest_exit_irqoff(void)
+static __always_inline void vtime_account_guest_exit(void)
 {
-	context_tracking_guest_exit();
-
-	instrumentation_begin();
 	if (vtime_accounting_enabled_this_cpu())
 		vtime_guest_exit(current);
 	else
 		current->flags &= ~PF_VCPU;
+}
+
+static __always_inline void guest_exit_irqoff(void)
+{
+	context_tracking_guest_exit();
+
+	instrumentation_begin();
+	vtime_account_guest_exit();
 	instrumentation_end();
 }
 
@@ -166,12 +171,17 @@ static __always_inline void guest_enter_irqoff(void)
 
 static __always_inline void context_tracking_guest_exit(void) { }
 
+static __always_inline void vtime_account_guest_exit(void)
+{
+	vtime_account_kernel(current);
+	current->flags &= ~PF_VCPU;
+}
+
 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;
+	vtime_account_guest_exit();
 	instrumentation_end();
 }
 #endif /* CONFIG_VIRT_CPU_ACCOUNTING_GEN */