From 4ae7dc97f726ea95c58ac58af71cc034ad22d7de Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Mon, 1 Feb 2021 00:05:48 +0100 Subject: entry/kvm: Explicitly flush pending rcuog wakeup before last rescheduling point Following the idle loop model, cleanly check for pending rcuog wakeup before the last rescheduling point upon resuming to guest mode. This way we can avoid to do it from rcu_user_enter() with the last resort self-IPI hack that enforces rescheduling. Suggested-by: Peter Zijlstra Signed-off-by: Frederic Weisbecker Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20210131230548.32970-6-frederic@kernel.org --- include/linux/entry-kvm.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'include') diff --git a/include/linux/entry-kvm.h b/include/linux/entry-kvm.h index 9b93f8584ff7..8b2b1d68b954 100644 --- a/include/linux/entry-kvm.h +++ b/include/linux/entry-kvm.h @@ -46,6 +46,20 @@ static inline int arch_xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu, */ int xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu); +/** + * xfer_to_guest_mode_prepare - Perform last minute preparation work that + * need to be handled while IRQs are disabled + * upon entering to guest. + * + * Has to be invoked with interrupts disabled before the last call + * to xfer_to_guest_mode_work_pending(). + */ +static inline void xfer_to_guest_mode_prepare(void) +{ + lockdep_assert_irqs_disabled(); + rcu_nocb_flush_deferred_wakeup(); +} + /** * __xfer_to_guest_mode_work_pending - Check if work is pending * -- cgit v1.2.3