linux-kernel - [PATCH v3 5/9] sched/vtime: Move guest enter/exit vtime accounting to vtime.h

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Message-Id: <20210415222106.1643837-6-seanjc@google.com>
Date:   Thu, 15 Apr 2021 15:21:02 -0700
From:   Sean Christopherson <seanjc@...gle.com>
To:     Paolo Bonzini <pbonzini@...hat.com>
Cc:     Sean Christopherson <seanjc@...gle.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Joerg Roedel <joro@...tes.org>, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org, Thomas Gleixner <tglx@...utronix.de>,
        Michael Tokarev <mjt@....msk.ru>,
        Christian Borntraeger <borntraeger@...ibm.com>
Subject: [PATCH v3 5/9] sched/vtime: Move guest enter/exit vtime accounting to vtime.h

Provide separate helpers for guest enter vtime accounting (in addition to
the existing guest exit helpers), and move all vtime accounting helpers
to vtime.h where the existing #ifdef infrastructure can be leveraged to
better delineate the different types of accounting.  This will also allow
future cleanups via deduplication of context tracking code.

Opportunstically delete the vtime_account_kernel() stub now that all
callers are wrapped with CONFIG_VIRT_CPU_ACCOUNTING_NATIVE=y.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 include/linux/context_tracking.h | 17 +-----------
 include/linux/vtime.h            | 46 +++++++++++++++++++++++++++-----
 2 files changed, 41 insertions(+), 22 deletions(-)

diff --git a/include/linux/context_tracking.h b/include/linux/context_tracking.h
index 7cf03a8e5708..1c05035396ad 100644
--- a/include/linux/context_tracking.h
+++ b/include/linux/context_tracking.h
@@ -137,14 +137,6 @@ static __always_inline void context_tracking_guest_exit_irqoff(void)
 		__context_tracking_exit(CONTEXT_GUEST);
 }
 
-static __always_inline void vtime_account_guest_exit(void)
-{
-	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_irqoff();
@@ -163,20 +155,13 @@ static __always_inline void guest_enter_irqoff(void)
 	 * to flush.
 	 */
 	instrumentation_begin();
-	vtime_account_kernel(current);
-	current->flags |= PF_VCPU;
+	vtime_account_guest_enter();
 	rcu_virt_note_context_switch(smp_processor_id());
 	instrumentation_end();
 }
 
 static __always_inline void context_tracking_guest_exit_irqoff(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();
diff --git a/include/linux/vtime.h b/include/linux/vtime.h
index 6a4317560539..3684487d01e1 100644
--- a/include/linux/vtime.h
+++ b/include/linux/vtime.h
@@ -3,21 +3,18 @@
 #define _LINUX_KERNEL_VTIME_H
 
 #include <linux/context_tracking_state.h>
+#include <linux/sched.h>
+
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 #include <asm/vtime.h>
 #endif
 
-
-struct task_struct;
-
 /*
  * Common vtime APIs
  */
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
 extern void vtime_account_kernel(struct task_struct *tsk);
 extern void vtime_account_idle(struct task_struct *tsk);
-#else /* !CONFIG_VIRT_CPU_ACCOUNTING */
-static inline void vtime_account_kernel(struct task_struct *tsk) { }
 #endif /* !CONFIG_VIRT_CPU_ACCOUNTING */
 
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
@@ -55,6 +52,18 @@ static inline void vtime_flush(struct task_struct *tsk) { }
 static inline bool vtime_accounting_enabled_this_cpu(void) { return true; }
 extern void vtime_task_switch(struct task_struct *prev);
 
+static __always_inline void vtime_account_guest_enter(void)
+{
+	vtime_account_kernel(current);
+	current->flags |= PF_VCPU;
+}
+
+static __always_inline void vtime_account_guest_exit(void)
+{
+	vtime_account_kernel(current);
+	current->flags &= ~PF_VCPU;
+}
+
 #elif defined(CONFIG_VIRT_CPU_ACCOUNTING_GEN)
 
 /*
@@ -86,12 +95,37 @@ static inline void vtime_task_switch(struct task_struct *prev)
 		vtime_task_switch_generic(prev);
 }
 
+static __always_inline void vtime_account_guest_enter(void)
+{
+	if (vtime_accounting_enabled_this_cpu())
+		vtime_guest_enter(current);
+	else
+		current->flags |= PF_VCPU;
+}
+
+static __always_inline void vtime_account_guest_exit(void)
+{
+	if (vtime_accounting_enabled_this_cpu())
+		vtime_guest_exit(current);
+	else
+		current->flags &= ~PF_VCPU;
+}
+
 #else /* !CONFIG_VIRT_CPU_ACCOUNTING */
 
-static inline bool vtime_accounting_enabled_cpu(int cpu) {return false; }
 static inline bool vtime_accounting_enabled_this_cpu(void) { return false; }
 static inline void vtime_task_switch(struct task_struct *prev) { }
 
+static __always_inline void vtime_account_guest_enter(void)
+{
+	current->flags |= PF_VCPU;
+}
+
+static __always_inline void vtime_account_guest_exit(void)
+{
+	current->flags &= ~PF_VCPU;
+}
+
 #endif
 
 
-- 
2.31.1.368.gbe11c130af-goog