diff mbox series

[RFC,33/86] entry/kvm: handle TIF_NEED_RESCHED_LAZY

Message ID 20231107215742.363031-34-ankur.a.arora@oracle.com (mailing list archive)
State New
Headers show
Series Make the kernel preemptible | expand

Commit Message

Ankur Arora Nov. 7, 2023, 9:57 p.m. UTC 
Executing in xfer_to_guest_mode_work() we are free of kernel
entanglements that cannot span preemption.

So, handle TIF_NEED_RESCHED_LAZY alongside TIF_NEED_RESCHED.

Also, while we at it, remove the explicit check for need_resched()
in the exit condition as that is already covered in the loop
condition.

Originally-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com>
---
 include/linux/entry-kvm.h | 2 +-
 kernel/entry/kvm.c        | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/include/linux/entry-kvm.h b/include/linux/entry-kvm.h
index 6813171afccb..674a622c91be 100644
--- a/include/linux/entry-kvm.h
+++ b/include/linux/entry-kvm.h
@@ -18,7 +18,7 @@ 
 
 #define XFER_TO_GUEST_MODE_WORK						\
 	(_TIF_NEED_RESCHED | _TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL |	\
-	 _TIF_NOTIFY_RESUME | ARCH_XFER_TO_GUEST_MODE_WORK)
+	 _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED_LAZY | ARCH_XFER_TO_GUEST_MODE_WORK)
 
 struct kvm_vcpu;
 
diff --git a/kernel/entry/kvm.c b/kernel/entry/kvm.c
index 2e0f75bcb7fd..8485f63863af 100644
--- a/kernel/entry/kvm.c
+++ b/kernel/entry/kvm.c
@@ -13,7 +13,7 @@  static int xfer_to_guest_mode_work(struct kvm_vcpu *vcpu, unsigned long ti_work)
 			return -EINTR;
 		}
 
-		if (ti_work & _TIF_NEED_RESCHED)
+		if (ti_work & (_TIF_NEED_RESCHED | _TIF_NEED_RESCHED_LAZY))
 			schedule();
 
 		if (ti_work & _TIF_NOTIFY_RESUME)
@@ -24,7 +24,7 @@  static int xfer_to_guest_mode_work(struct kvm_vcpu *vcpu, unsigned long ti_work)
 			return ret;
 
 		ti_work = read_thread_flags();
-	} while (ti_work & XFER_TO_GUEST_MODE_WORK || need_resched());
+	} while (ti_work & XFER_TO_GUEST_MODE_WORK);
 	return 0;
 }