Commit d7621c28 authored by Stefano Garzarella's avatar Stefano Garzarella Committed by Michael S. Tsirkin
Browse files

vdpa_sim: replace the spinlock with a mutex to protect the state 



The spinlock we use to protect the state of the simulator is sometimes
held for a long time (for example, when devices handle requests).

This also prevents us from calling functions that might sleep (such as
kthread_flush_work() in the next patch), and thus having to release
and retake the lock.

For these reasons, let's replace the spinlock with a mutex that gives
us more flexibility.

Suggested-by: default avatarJason Wang <jasowang@redhat.com>
Acked-by: default avatarJason Wang <jasowang@redhat.com>
Signed-off-by: default avatarStefano Garzarella <sgarzare@redhat.com>
Message-Id: <20230404131730.45920-1-sgarzare@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 76acfa7b

drivers/vdpa/vdpa_sim/vdpa_sim.c

+17 −17
Original line number Diff line number Diff line
@@ -178,7 +178,7 @@ struct vdpasim *vdpasim_create(struct vdpasim_dev_attr *dev_attr, 
	if (IS_ERR(vdpasim->worker))

		goto err_iommu;



	spin_lock_init(&vdpasim->lock);

	mutex_init(&vdpasim->mutex);

	spin_lock_init(&vdpasim->iommu_lock);



	dev->dma_mask = &dev->coherent_dma_mask;
@@ -286,13 +286,13 @@ static void vdpasim_set_vq_ready(struct vdpa_device *vdpa, u16 idx, bool ready) 
	struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];

	bool old_ready;



	spin_lock(&vdpasim->lock);

	mutex_lock(&vdpasim->mutex);

	old_ready = vq->ready;

	vq->ready = ready;

	if (vq->ready && !old_ready) {

		vdpasim_queue_ready(vdpasim, idx);

	}

	spin_unlock(&vdpasim->lock);

	mutex_unlock(&vdpasim->mutex);

}



static bool vdpasim_get_vq_ready(struct vdpa_device *vdpa, u16 idx)
@@ -310,9 +310,9 @@ static int vdpasim_set_vq_state(struct vdpa_device *vdpa, u16 idx, 
	struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];

	struct vringh *vrh = &vq->vring;



	spin_lock(&vdpasim->lock);

	mutex_lock(&vdpasim->mutex);

	vrh->last_avail_idx = state->split.avail_index;

	spin_unlock(&vdpasim->lock);

	mutex_unlock(&vdpasim->mutex);



	return 0;

}
@@ -409,9 +409,9 @@ static u8 vdpasim_get_status(struct vdpa_device *vdpa) 
	struct vdpasim *vdpasim = vdpa_to_sim(vdpa);

	u8 status;



	spin_lock(&vdpasim->lock);

	mutex_lock(&vdpasim->mutex);

	status = vdpasim->status;

	spin_unlock(&vdpasim->lock);

	mutex_unlock(&vdpasim->mutex);



	return status;

}
@@ -420,19 +420,19 @@ static void vdpasim_set_status(struct vdpa_device *vdpa, u8 status) 
{

	struct vdpasim *vdpasim = vdpa_to_sim(vdpa);



	spin_lock(&vdpasim->lock);

	mutex_lock(&vdpasim->mutex);

	vdpasim->status = status;

	spin_unlock(&vdpasim->lock);

	mutex_unlock(&vdpasim->mutex);

}



static int vdpasim_reset(struct vdpa_device *vdpa)

{

	struct vdpasim *vdpasim = vdpa_to_sim(vdpa);



	spin_lock(&vdpasim->lock);

	mutex_lock(&vdpasim->mutex);

	vdpasim->status = 0;

	vdpasim_do_reset(vdpasim);

	spin_unlock(&vdpasim->lock);

	mutex_unlock(&vdpasim->mutex);



	return 0;

}
@@ -441,9 +441,9 @@ static int vdpasim_suspend(struct vdpa_device *vdpa) 
{

	struct vdpasim *vdpasim = vdpa_to_sim(vdpa);



	spin_lock(&vdpasim->lock);

	mutex_lock(&vdpasim->mutex);

	vdpasim->running = false;

	spin_unlock(&vdpasim->lock);

	mutex_unlock(&vdpasim->mutex);



	return 0;

}
@@ -453,7 +453,7 @@ static int vdpasim_resume(struct vdpa_device *vdpa) 
	struct vdpasim *vdpasim = vdpa_to_sim(vdpa);

	int i;



	spin_lock(&vdpasim->lock);

	mutex_lock(&vdpasim->mutex);

	vdpasim->running = true;



	if (vdpasim->pending_kick) {
@@ -464,7 +464,7 @@ static int vdpasim_resume(struct vdpa_device *vdpa) 
		vdpasim->pending_kick = false;

	}



	spin_unlock(&vdpasim->lock);

	mutex_unlock(&vdpasim->mutex);



	return 0;

}
@@ -536,14 +536,14 @@ static int vdpasim_set_group_asid(struct vdpa_device *vdpa, unsigned int group, 


	iommu = &vdpasim->iommu[asid];



	spin_lock(&vdpasim->lock);

	mutex_lock(&vdpasim->mutex);



	for (i = 0; i < vdpasim->dev_attr.nvqs; i++)

		if (vdpasim_get_vq_group(vdpa, i) == group)

			vringh_set_iotlb(&vdpasim->vqs[i].vring, iommu,

					 &vdpasim->iommu_lock);



	spin_unlock(&vdpasim->lock);

	mutex_unlock(&vdpasim->mutex);



	return 0;

}

drivers/vdpa/vdpa_sim/vdpa_sim.h

+2 −2
Original line number Diff line number Diff line
@@ -60,8 +60,8 @@ struct vdpasim { 
	struct kthread_worker *worker;

	struct kthread_work work;

	struct vdpasim_dev_attr dev_attr;

	/* spinlock to synchronize virtqueue state */

	spinlock_t lock;

	/* mutex to synchronize virtqueue state */

	struct mutex mutex;

	/* virtio config according to device type */

	void *config;

	struct vhost_iotlb *iommu;

drivers/vdpa/vdpa_sim/vdpa_sim_blk.c

+2 −2
Original line number Diff line number Diff line
@@ -290,7 +290,7 @@ static void vdpasim_blk_work(struct vdpasim *vdpasim) 
	bool reschedule = false;

	int i;



	spin_lock(&vdpasim->lock);

	mutex_lock(&vdpasim->mutex);



	if (!(vdpasim->status & VIRTIO_CONFIG_S_DRIVER_OK))

		goto out;
@@ -321,7 +321,7 @@ static void vdpasim_blk_work(struct vdpasim *vdpasim) 
		}

	}

out:

	spin_unlock(&vdpasim->lock);

	mutex_unlock(&vdpasim->mutex);



	if (reschedule)

		vdpasim_schedule_work(vdpasim);

drivers/vdpa/vdpa_sim/vdpa_sim_net.c

+2 −2
Original line number Diff line number Diff line
@@ -201,7 +201,7 @@ static void vdpasim_net_work(struct vdpasim *vdpasim) 
	u64 rx_drops = 0, rx_overruns = 0, rx_errors = 0, tx_errors = 0;

	int err;



	spin_lock(&vdpasim->lock);

	mutex_lock(&vdpasim->mutex);



	if (!vdpasim->running)

		goto out;
@@ -264,7 +264,7 @@ static void vdpasim_net_work(struct vdpasim *vdpasim) 
	}



out:

	spin_unlock(&vdpasim->lock);

	mutex_unlock(&vdpasim->mutex);



	u64_stats_update_begin(&net->tx_stats.syncp);

	net->tx_stats.pkts += tx_pkts;