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[95.117.170.66]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-49cee7fec25sm523841335e9.13.2026.09.07.22.39.42 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Mon, 07 Sep 2026 22:39:44 -0700 (PDT) From: Karl Mehltretter To: "Michael S. Tsirkin" , Jason Wang , Gerd Hoffmann Cc: Karl Mehltretter , Xuan Zhuo , =?UTF-8?q?Eugenio=20P=C3=A9rez?= , Dmitry Torokhov , Rusty Russell , Pawel Moll , Cornelia Huck , Halil Pasic , Eric Farman , Richard Weinberger , Anton Ivanov , Johannes Berg , Hans de Goede , =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= , Vadim Pasternak , Bjorn Andersson , Mathieu Poirier , virtualization@lists.linux.dev, linux-input@vger.kernel.org, linux-s390@vger.kernel.org, kvm@vger.kernel.org, linux-um@lists.infradead.org, platform-driver-x86@vger.kernel.org, linux-remoteproc@vger.kernel.org, linux-kernel@vger.kernel.org, Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle Subject: [PATCH v3 4/6] um: virtio_uml: implement synchronize_cbs() Date: Tue, 8 Sep 2026 07:38:15 +0200 Message-Id: <20260908053817.26065-5-kmehltretter@gmail.com> X-Mailer: git-send-email 2.39.5 (Apple Git-154) In-Reply-To: <20260908053817.26065-1-kmehltretter@gmail.com> References: <20260908053817.26065-1-kmehltretter@gmail.com> Precedence: bulk X-Mailing-List: linux-s390@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit virtio_uml invokes virtqueue callbacks from vu_interrupt() and vu_req_interrupt(), which share vu_dev->irq. The core's synchronize_rcu() fallback already covers these IRQ handlers. Implement synchronize_cbs() with synchronize_irq() to synchronize with that IRQ instead of waiting for an RCU grace period. Assisted-by: LLM Signed-off-by: Karl Mehltretter --- arch/um/drivers/virtio_uml.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/arch/um/drivers/virtio_uml.c b/arch/um/drivers/virtio_uml.c index 7425a8548141..1f2e62e29a27 100644 --- a/arch/um/drivers/virtio_uml.c +++ b/arch/um/drivers/virtio_uml.c @@ -20,6 +20,7 @@ * * Based on Virtio MMIO driver by Pawel Moll, copyright 2011-2014, ARM Ltd. */ +#include #include #include #include @@ -869,6 +870,14 @@ static void vu_reset(struct virtio_device *vdev) vu_dev->status = 0; } +static void vu_synchronize_cbs(struct virtio_device *vdev) +{ + struct virtio_uml_device *vu_dev = to_virtio_uml_device(vdev); + + if (vu_dev->irq != UM_IRQ_ALLOC) + synchronize_irq(vu_dev->irq); +} + static void vu_del_vq(struct virtqueue *vq) { struct virtio_uml_vq_info *info = vq->priv; @@ -1121,6 +1130,7 @@ static const struct virtio_config_ops virtio_uml_config_ops = { .reset = vu_reset, .find_vqs = vu_find_vqs, .del_vqs = vu_del_vqs, + .synchronize_cbs = vu_synchronize_cbs, .get_features = vu_get_features, .finalize_features = vu_finalize_features, .bus_name = vu_bus_name, -- 2.39.5 (Apple Git-154)