Commit 86e182fe authored by Zhu Lingshan's avatar Zhu Lingshan Committed by Michael S. Tsirkin
Browse files

vhost_vdpa: remove unnecessary spin_lock in vhost_vring_call 



This commit removed unnecessary spin_locks in vhost_vring_call
and related operations. Because we manipulate irq offloading
contents in vhost_vdpa ioctl code path which is already
protected by dev mutex and vq mutex.

Signed-off-by: default avatarZhu Lingshan <lingshan.zhu@intel.com>
Link: https://lore.kernel.org/r/20200909065234.3313-1-lingshan.zhu@intel.com


Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Acked-by: default avatarJason Wang <jasowang@redhat.com>
parent 5745bcfb

drivers/vhost/vdpa.c

+1 −7
Original line number Diff line number Diff line
@@ -96,26 +96,20 @@ static void vhost_vdpa_setup_vq_irq(struct vhost_vdpa *v, u16 qid) 
		return;



	irq = ops->get_vq_irq(vdpa, qid);

	spin_lock(&vq->call_ctx.ctx_lock);

	irq_bypass_unregister_producer(&vq->call_ctx.producer);

	if (!vq->call_ctx.ctx || irq < 0) {

		spin_unlock(&vq->call_ctx.ctx_lock);

	if (!vq->call_ctx.ctx || irq < 0)

		return;

	}



	vq->call_ctx.producer.token = vq->call_ctx.ctx;

	vq->call_ctx.producer.irq = irq;

	ret = irq_bypass_register_producer(&vq->call_ctx.producer);

	spin_unlock(&vq->call_ctx.ctx_lock);

}



static void vhost_vdpa_unsetup_vq_irq(struct vhost_vdpa *v, u16 qid)

{

	struct vhost_virtqueue *vq = &v->vqs[qid];



	spin_lock(&vq->call_ctx.ctx_lock);

	irq_bypass_unregister_producer(&vq->call_ctx.producer);

	spin_unlock(&vq->call_ctx.ctx_lock);

}



static void vhost_vdpa_reset(struct vhost_vdpa *v)

drivers/vhost/vhost.c

+0 −3
Original line number Diff line number Diff line
@@ -302,7 +302,6 @@ static void vhost_vring_call_reset(struct vhost_vring_call *call_ctx) 
{

	call_ctx->ctx = NULL;

	memset(&call_ctx->producer, 0x0, sizeof(struct irq_bypass_producer));

	spin_lock_init(&call_ctx->ctx_lock);

}



static void vhost_vq_reset(struct vhost_dev *dev,
@@ -1650,9 +1649,7 @@ long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *arg 
			break;

		}



		spin_lock(&vq->call_ctx.ctx_lock);

		swap(ctx, vq->call_ctx.ctx);

		spin_unlock(&vq->call_ctx.ctx_lock);

		break;

	case VHOST_SET_VRING_ERR:

		if (copy_from_user(&f, argp, sizeof f)) {

drivers/vhost/vhost.h

+0 −1
Original line number Diff line number Diff line
@@ -64,7 +64,6 @@ enum vhost_uaddr_type { 
struct vhost_vring_call {

	struct eventfd_ctx *ctx;

	struct irq_bypass_producer producer;

	spinlock_t ctx_lock;

};



/* The virtqueue structure describes a queue attached to a device. */

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