From e38632dd71818d99bcebeb55f27dc764a9f7d547 Mon Sep 17 00:00:00 2001 From: Xie Yongji Date: Thu, 23 Mar 2023 13:30:41 +0800 Subject: [PATCH] vduse: Signal vq trigger eventfd directly if possible Now the vdpa callback will associate an trigger eventfd in some cases. For performance reasons, VDUSE can signal it directly during irq injection. Signed-off-by: Xie Yongji Acked-by: Jason Wang Message-Id: <20230323053043.35-10-xieyongji@bytedance.com> Signed-off-by: Michael S. Tsirkin --- drivers/vdpa/vdpa_user/vduse_dev.c | 30 ++++++++++++++++++++++++++---- 1 file changed, 26 insertions(+), 4 deletions(-) diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c index 77da368..8c06f6a 100644 --- a/drivers/vdpa/vdpa_user/vduse_dev.c +++ b/drivers/vdpa/vdpa_user/vduse_dev.c @@ -459,6 +459,7 @@ static void vduse_dev_reset(struct vduse_dev *dev) spin_lock(&vq->irq_lock); vq->cb.callback = NULL; vq->cb.private = NULL; + vq->cb.trigger = NULL; spin_unlock(&vq->irq_lock); flush_work(&vq->inject); flush_work(&vq->kick); @@ -524,6 +525,7 @@ static void vduse_vdpa_set_vq_cb(struct vdpa_device *vdpa, u16 idx, spin_lock(&vq->irq_lock); vq->cb.callback = cb->callback; vq->cb.private = cb->private; + vq->cb.trigger = cb->trigger; spin_unlock(&vq->irq_lock); } @@ -941,6 +943,23 @@ static void vduse_vq_irq_inject(struct work_struct *work) spin_unlock_irq(&vq->irq_lock); } +static bool vduse_vq_signal_irqfd(struct vduse_virtqueue *vq) +{ + bool signal = false; + + if (!vq->cb.trigger) + return false; + + spin_lock_irq(&vq->irq_lock); + if (vq->ready && vq->cb.trigger) { + eventfd_signal(vq->cb.trigger, 1); + signal = true; + } + spin_unlock_irq(&vq->irq_lock); + + return signal; +} + static int vduse_dev_queue_irq_work(struct vduse_dev *dev, struct work_struct *irq_work, int irq_effective_cpu) @@ -1243,11 +1262,14 @@ static long vduse_dev_ioctl(struct file *file, unsigned int cmd, if (index >= dev->vq_num) break; + ret = 0; index = array_index_nospec(index, dev->vq_num); - - vduse_vq_update_effective_cpu(dev->vqs[index]); - ret = vduse_dev_queue_irq_work(dev, &dev->vqs[index]->inject, - dev->vqs[index]->irq_effective_cpu); + if (!vduse_vq_signal_irqfd(dev->vqs[index])) { + vduse_vq_update_effective_cpu(dev->vqs[index]); + ret = vduse_dev_queue_irq_work(dev, + &dev->vqs[index]->inject, + dev->vqs[index]->irq_effective_cpu); + } break; } case VDUSE_IOTLB_REG_UMEM: { -- 2.7.4