[PATCH] vduse: Use proper spinlock for IRQ injection

From: Maxime Coquelin
Date: Wed Jul 05 2023 - 07:46:24 EST


The IRQ injection work used spin_lock_irq() to protect the
scheduling of the softirq, but spin_lock_bh() should be
used.

With spin_lock_irq(), we noticed delay of more than 6
seconds between the time a NAPI polling work is scheduled
and the time it is executed.

Fixes: c8a6153b6c59 ("vduse: Introduce VDUSE - vDPA Device in Userspace")
Cc: xieyongji@xxxxxxxxxxxxx

Suggested-by: Jason Wang <jasowang@xxxxxxxxxx>
Signed-off-by: Maxime Coquelin <maxime.coquelin@xxxxxxxxxx>
---
drivers/vdpa/vdpa_user/vduse_dev.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c
index dc38ed21319d..df7869537ef1 100644
--- a/drivers/vdpa/vdpa_user/vduse_dev.c
+++ b/drivers/vdpa/vdpa_user/vduse_dev.c
@@ -935,10 +935,10 @@ static void vduse_dev_irq_inject(struct work_struct *work)
{
struct vduse_dev *dev = container_of(work, struct vduse_dev, inject);

- spin_lock_irq(&dev->irq_lock);
+ spin_lock_bh(&dev->irq_lock);
if (dev->config_cb.callback)
dev->config_cb.callback(dev->config_cb.private);
- spin_unlock_irq(&dev->irq_lock);
+ spin_unlock_bh(&dev->irq_lock);
}

static void vduse_vq_irq_inject(struct work_struct *work)
@@ -946,10 +946,10 @@ static void vduse_vq_irq_inject(struct work_struct *work)
struct vduse_virtqueue *vq = container_of(work,
struct vduse_virtqueue, inject);

- spin_lock_irq(&vq->irq_lock);
+ spin_lock_bh(&vq->irq_lock);
if (vq->ready && vq->cb.callback)
vq->cb.callback(vq->cb.private);
- spin_unlock_irq(&vq->irq_lock);
+ spin_unlock_bh(&vq->irq_lock);
}

static bool vduse_vq_signal_irqfd(struct vduse_virtqueue *vq)
--
2.41.0