From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Thierry Subject: [PATCH kvmtool v2 13/13] virtio/console: Implement reset Date: Thu, 10 Jan 2019 14:12:50 +0000 Message-ID: <1547129570-14351-14-git-send-email-julien.thierry@arm.com> References: <1547129570-14351-1-git-send-email-julien.thierry@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: will.deacon@arm.com, kraxel@redhat.com To: kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu Return-path: In-Reply-To: <1547129570-14351-1-git-send-email-julien.thierry@arm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu List-Id: kvm.vger.kernel.org From: Jean-Philippe Brucker The virtio-console reset cancels all running jobs. Unfortunately we don't have a good way to prevent the term polling thread from getting in the way, read invalid data during reset and cause a segfault. To prevent this, move all handling of the Rx queue in the threadpool job. Signed-off-by: Jean-Philippe Brucker Signed-off-by: Julien Thierry --- virtio/console.c | 32 ++++++++++++++++++++------------ 1 file changed, 20 insertions(+), 12 deletions(-) diff --git a/virtio/console.c b/virtio/console.c index d2b312c..f1be025 100644 --- a/virtio/console.c +++ b/virtio/console.c @@ -35,8 +35,6 @@ struct con_dev { struct virt_queue vqs[VIRTIO_CONSOLE_NUM_QUEUES]; struct virtio_console_config config; u32 features; - - pthread_cond_t poll_cond; int vq_ready; struct thread_pool__job jobs[VIRTIO_CONSOLE_NUM_QUEUES]; @@ -44,7 +42,6 @@ struct con_dev { static struct con_dev cdev = { .mutex = MUTEX_INITIALIZER, - .poll_cond = PTHREAD_COND_INITIALIZER, .vq_ready = 0, @@ -68,16 +65,10 @@ static void virtio_console__inject_interrupt_callback(struct kvm *kvm, void *par u16 head; int len; - if (kvm->cfg.active_console != CONSOLE_VIRTIO) - return; - mutex_lock(&cdev.mutex); vq = param; - if (!cdev.vq_ready) - pthread_cond_wait(&cdev.poll_cond, &cdev.mutex.mutex); - if (term_readable(0) && virt_queue__available(vq)) { head = virt_queue__get_iov(vq, iov, &out, &in, kvm); len = term_getc_iov(kvm, iov, in, 0); @@ -90,8 +81,13 @@ static void virtio_console__inject_interrupt_callback(struct kvm *kvm, void *par void virtio_console__inject_interrupt(struct kvm *kvm) { - virtio_console__inject_interrupt_callback(kvm, - &cdev.vqs[VIRTIO_CONSOLE_RX_QUEUE]); + if (kvm->cfg.active_console != CONSOLE_VIRTIO) + return; + + mutex_lock(&cdev.mutex); + if (cdev.vq_ready) + thread_pool__do_job(&cdev.jobs[VIRTIO_CONSOLE_RX_QUEUE]); + mutex_unlock(&cdev.mutex); } static void virtio_console_handle_callback(struct kvm *kvm, void *param) @@ -168,13 +164,24 @@ static int init_vq(struct kvm *kvm, void *dev, u32 vq, u32 page_size, u32 align, /* Tell the waiting poll thread that we're ready to go */ mutex_lock(&cdev.mutex); cdev.vq_ready = 1; - pthread_cond_signal(&cdev.poll_cond); mutex_unlock(&cdev.mutex); } return 0; } +static void exit_vq(struct kvm *kvm, void *dev, u32 vq) +{ + if (vq == VIRTIO_CONSOLE_RX_QUEUE) { + mutex_lock(&cdev.mutex); + cdev.vq_ready = 0; + mutex_unlock(&cdev.mutex); + thread_pool__cancel_job(&cdev.jobs[vq]); + } else if (vq == VIRTIO_CONSOLE_TX_QUEUE) { + thread_pool__cancel_job(&cdev.jobs[vq]); + } +} + static int notify_vq(struct kvm *kvm, void *dev, u32 vq) { struct con_dev *cdev = dev; @@ -213,6 +220,7 @@ static struct virtio_ops con_dev_virtio_ops = { .set_guest_features = set_guest_features, .get_vq_count = get_vq_count, .init_vq = init_vq, + .exit_vq = exit_vq, .notify_status = notify_status, .notify_vq = notify_vq, .get_vq = get_vq, -- 1.9.1