From: Sean Christopherson <seanjc@google.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
Thomas Gleixner <tglx@linutronix.de>,
Christian Borntraeger <borntraeger@de.ibm.com>,
Michael Tokarev <mjt@tls.msk.ru>
Subject: [RFC PATCH 1/7] sched/vtime: Move guest enter/exit vtime accounting to separate helpers
Date: Tue, 13 Apr 2021 11:29:27 -0700 [thread overview]
Message-ID: <20210413182933.1046389-2-seanjc@google.com> (raw)
In-Reply-To: <20210413182933.1046389-1-seanjc@google.com>
Provide separate helpers for guest enter/exit vtime accounting 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.
Opportunstically delete the vtime_account_kernel() stub now that all
callers are wrapped with CONFIG_VIRT_CPU_ACCOUNTING_NATIVE=y.
No functional change intended.
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
include/linux/context_tracking.h | 17 +++---------
include/linux/vtime.h | 45 +++++++++++++++++++++++++++++---
2 files changed, 45 insertions(+), 17 deletions(-)
diff --git a/include/linux/context_tracking.h b/include/linux/context_tracking.h
index bceb06498521..58f9a7251d3b 100644
--- a/include/linux/context_tracking.h
+++ b/include/linux/context_tracking.h
@@ -102,16 +102,12 @@ 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)
{
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())
@@ -137,10 +133,7 @@ static __always_inline void guest_exit_irqoff(void)
__context_tracking_exit(CONTEXT_GUEST);
instrumentation_begin();
- if (vtime_accounting_enabled_this_cpu())
- vtime_guest_exit(current);
- else
- current->flags &= ~PF_VCPU;
+ vtime_account_guest_exit();
instrumentation_end();
}
@@ -153,8 +146,7 @@ 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();
}
@@ -163,8 +155,7 @@ 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 */
diff --git a/include/linux/vtime.h b/include/linux/vtime.h
index 041d6524d144..f30b472a2201 100644
--- a/include/linux/vtime.h
+++ b/include/linux/vtime.h
@@ -3,6 +3,8 @@
#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
@@ -18,6 +20,17 @@ struct task_struct;
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)
+{
+
+}
+
#elif defined(CONFIG_VIRT_CPU_ACCOUNTING_GEN)
/*
@@ -49,12 +62,38 @@ 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
/*
@@ -63,9 +102,7 @@ static inline void vtime_task_switch(struct task_struct *prev) { }
#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 */
+#endif /* CONFIG_VIRT_CPU_ACCOUNTING */
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
extern void arch_vtime_task_switch(struct task_struct *tsk);
--
2.31.1.295.g9ea45b61b8-goog
next prev parent reply other threads:[~2021-04-13 18:29 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-13 18:29 [RFC PATCH 0/7] KVM: Fix tick-based vtime accounting on x86 Sean Christopherson
2021-04-13 18:29 ` Sean Christopherson [this message]
2021-04-13 18:29 ` [RFC PATCH 2/7] context_tracking: Move guest enter/exit logic to standalone helpers Sean Christopherson
2021-04-13 18:29 ` [RFC PATCH 3/7] context_tracking: Consolidate guest enter/exit wrappers Sean Christopherson
2021-04-13 18:29 ` [RFC PATCH 4/7] context_tracking: KVM: Move guest enter/exit wrappers to KVM's domain Sean Christopherson
2021-04-13 18:29 ` [RFC PATCH 5/7] KVM: Move vtime accounting of guest exit to separate helper Sean Christopherson
2021-04-13 18:29 ` [RFC PATCH 6/7] KVM: x86: Consolidate guest enter/exit logic to common helpers Sean Christopherson
2021-04-13 18:29 ` [RFC PATCH 7/7] KVM: x86: Defer tick-based accounting 'til after IRQ handling Sean Christopherson
2021-04-14 17:33 ` [RFC PATCH 0/7] KVM: Fix tick-based vtime accounting on x86 Thomas Gleixner
2021-04-14 17:57 ` Sean Christopherson
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