From: David Woodhouse <dwmw2@infradead.org>
To: bonzini@redhat.com
Cc: Alex Williamson <alex.williamson@redhat.com>,
Cornelia Huck <cohuck@redhat.com>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Jens Axboe <axboe@kernel.dk>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-fsdevel@vger.kernel.org
Subject: [PATCH 2/3] vfio/virqfd: Drain events from eventfd in virqfd_wakeup()
Date: Tue, 27 Oct 2020 13:55:22 +0000 [thread overview]
Message-ID: <20201027135523.646811-3-dwmw2@infradead.org> (raw)
In-Reply-To: <20201027135523.646811-1-dwmw2@infradead.org>
From: David Woodhouse <dwmw@amazon.co.uk>
Don't allow the events to accumulate in the eventfd counter, drain them
as they are handled.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
---
drivers/vfio/virqfd.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/vfio/virqfd.c b/drivers/vfio/virqfd.c
index 997cb5d0a657..414e98d82b02 100644
--- a/drivers/vfio/virqfd.c
+++ b/drivers/vfio/virqfd.c
@@ -46,6 +46,9 @@ static int virqfd_wakeup(wait_queue_entry_t *wait, unsigned mode, int sync, void
__poll_t flags = key_to_poll(key);
if (flags & EPOLLIN) {
+ u64 cnt;
+ eventfd_ctx_do_read(virqfd->eventfd, &cnt);
+
/* An event has been signaled, call function */
if ((!virqfd->handler ||
virqfd->handler(virqfd->opaque, virqfd->data)) &&
--
2.26.2
next prev parent reply other threads:[~2020-10-27 13:55 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-26 17:53 [RFC PATCH 1/2] sched/wait: Add add_wait_queue_priority() David Woodhouse
2020-10-26 17:53 ` [RFC PATCH 2/2] kvm/eventfd: Use priority waitqueue to catch events before userspace David Woodhouse
2020-10-27 8:01 ` Paolo Bonzini
2020-10-27 10:15 ` David Woodhouse
2020-10-27 13:55 ` [PATCH 0/3] Allow in-kernel consumers to drain events from eventfd David Woodhouse
2020-10-27 13:55 ` [PATCH 1/3] eventfd: Export eventfd_ctx_do_read() David Woodhouse
2020-10-27 13:55 ` David Woodhouse [this message]
2020-11-06 23:29 ` [PATCH 2/3] vfio/virqfd: Drain events from eventfd in virqfd_wakeup() Alex Williamson
2020-11-08 9:17 ` Paolo Bonzini
2020-10-27 13:55 ` [PATCH 3/3] kvm/eventfd: Drain events from eventfd in irqfd_wakeup() David Woodhouse
2020-10-27 18:41 ` kernel test robot
2020-10-27 18:41 ` kernel test robot
2020-10-27 21:42 ` kernel test robot
2020-10-27 21:42 ` kernel test robot
2020-10-27 23:13 ` kernel test robot
2020-10-27 23:13 ` kernel test robot
2020-10-27 14:39 ` [PATCH v2 0/2] Allow KVM IRQFD to consistently intercept events David Woodhouse
2020-10-27 14:39 ` [PATCH v2 1/2] sched/wait: Add add_wait_queue_priority() David Woodhouse
2020-10-27 19:09 ` Peter Zijlstra
2020-10-27 19:27 ` David Woodhouse
2020-10-27 20:30 ` Peter Zijlstra
2020-10-27 20:49 ` David Woodhouse
2020-10-27 21:32 ` David Woodhouse
2020-10-28 14:20 ` Peter Zijlstra
2020-10-28 14:44 ` Paolo Bonzini
2020-10-28 14:35 ` Peter Zijlstra
2020-11-04 9:35 ` David Woodhouse
2020-11-04 11:25 ` Paolo Bonzini
2020-11-06 10:17 ` Paolo Bonzini
2020-11-06 16:32 ` Alex Williamson
2020-11-06 17:18 ` David Woodhouse
2020-10-27 14:39 ` [PATCH v2 2/2] kvm/eventfd: Use priority waitqueue to catch events before userspace David Woodhouse
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