Commit 66640f4a authored by Xie Yongji's avatar Xie Yongji Committed by Michael S. Tsirkin
Browse files

vduse: Add sysfs interface for irq callback affinity 



Add sysfs interface for each vduse virtqueue to
get/set the affinity for irq callback. This might
be useful for performance tuning when the irq callback
affinity mask contains more than one CPU.

Signed-off-by: default avatarXie Yongji <xieyongji@bytedance.com>
Message-Id: <20230323053043.35-8-xieyongji@bytedance.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Acked-by: default avatarJason Wang <jasowang@redhat.com>
parent bfae1648

drivers/vdpa/vdpa_user/vduse_dev.c

+113 −11
Original line number Diff line number Diff line
@@ -61,6 +61,7 @@ struct vduse_virtqueue { 
	struct work_struct kick;

	int irq_effective_cpu;

	struct cpumask irq_affinity;

	struct kobject kobj;

};



struct vduse_dev;
@@ -1387,6 +1388,96 @@ static const struct file_operations vduse_dev_fops = { 
	.llseek		= noop_llseek,

};



static ssize_t irq_cb_affinity_show(struct vduse_virtqueue *vq, char *buf)

{

	return sprintf(buf, "%*pb\n", cpumask_pr_args(&vq->irq_affinity));

}



static ssize_t irq_cb_affinity_store(struct vduse_virtqueue *vq,

				     const char *buf, size_t count)

{

	cpumask_var_t new_value;

	int ret;



	if (!zalloc_cpumask_var(&new_value, GFP_KERNEL))

		return -ENOMEM;



	ret = cpumask_parse(buf, new_value);

	if (ret)

		goto free_mask;



	ret = -EINVAL;

	if (!cpumask_intersects(new_value, cpu_online_mask))

		goto free_mask;



	cpumask_copy(&vq->irq_affinity, new_value);

	ret = count;

free_mask:

	free_cpumask_var(new_value);

	return ret;

}



struct vq_sysfs_entry {

	struct attribute attr;

	ssize_t (*show)(struct vduse_virtqueue *vq, char *buf);

	ssize_t (*store)(struct vduse_virtqueue *vq, const char *buf,

			 size_t count);

};



static struct vq_sysfs_entry irq_cb_affinity_attr = __ATTR_RW(irq_cb_affinity);



static struct attribute *vq_attrs[] = {

	&irq_cb_affinity_attr.attr,

	NULL,

};

ATTRIBUTE_GROUPS(vq);



static ssize_t vq_attr_show(struct kobject *kobj, struct attribute *attr,

			    char *buf)

{

	struct vduse_virtqueue *vq = container_of(kobj,

					struct vduse_virtqueue, kobj);

	struct vq_sysfs_entry *entry = container_of(attr,

					struct vq_sysfs_entry, attr);



	if (!entry->show)

		return -EIO;



	return entry->show(vq, buf);

}



static ssize_t vq_attr_store(struct kobject *kobj, struct attribute *attr,

			     const char *buf, size_t count)

{

	struct vduse_virtqueue *vq = container_of(kobj,

					struct vduse_virtqueue, kobj);

	struct vq_sysfs_entry *entry = container_of(attr,

					struct vq_sysfs_entry, attr);



	if (!entry->store)

		return -EIO;



	return entry->store(vq, buf, count);

}



static const struct sysfs_ops vq_sysfs_ops = {

	.show = vq_attr_show,

	.store = vq_attr_store,

};



static void vq_release(struct kobject *kobj)

{

	struct vduse_virtqueue *vq = container_of(kobj,

					struct vduse_virtqueue, kobj);

	kfree(vq);

}



static const struct kobj_type vq_type = {

	.release	= vq_release,

	.sysfs_ops	= &vq_sysfs_ops,

	.default_groups	= vq_groups,

};



static void vduse_dev_deinit_vqs(struct vduse_dev *dev)

{

	int i;
@@ -1395,13 +1486,13 @@ static void vduse_dev_deinit_vqs(struct vduse_dev *dev) 
		return;



	for (i = 0; i < dev->vq_num; i++)

		kfree(dev->vqs[i]);

		kobject_put(&dev->vqs[i]->kobj);

	kfree(dev->vqs);

}



static int vduse_dev_init_vqs(struct vduse_dev *dev, u32 vq_align, u32 vq_num)

{

	int i;

	int ret, i;



	dev->vq_align = vq_align;

	dev->vq_num = vq_num;
@@ -1411,8 +1502,10 @@ static int vduse_dev_init_vqs(struct vduse_dev *dev, u32 vq_align, u32 vq_num) 


	for (i = 0; i < vq_num; i++) {

		dev->vqs[i] = kzalloc(sizeof(*dev->vqs[i]), GFP_KERNEL);

		if (!dev->vqs[i])

		if (!dev->vqs[i]) {

			ret = -ENOMEM;

			goto err;

		}



		dev->vqs[i]->index = i;

		dev->vqs[i]->irq_effective_cpu = IRQ_UNBOUND;
@@ -1421,15 +1514,23 @@ static int vduse_dev_init_vqs(struct vduse_dev *dev, u32 vq_align, u32 vq_num) 
		spin_lock_init(&dev->vqs[i]->kick_lock);

		spin_lock_init(&dev->vqs[i]->irq_lock);

		cpumask_setall(&dev->vqs[i]->irq_affinity);



		kobject_init(&dev->vqs[i]->kobj, &vq_type);

		ret = kobject_add(&dev->vqs[i]->kobj,

				  &dev->dev->kobj, "vq%d", i);

		if (ret) {

			kfree(dev->vqs[i]);

			goto err;

		}

	}



	return 0;

err:

	while (i--)

		kfree(dev->vqs[i]);

		kobject_put(&dev->vqs[i]->kobj);

	kfree(dev->vqs);

	dev->vqs = NULL;

	return -ENOMEM;

	return ret;

}



static struct vduse_dev *vduse_dev_create(void)
@@ -1607,10 +1708,6 @@ static int vduse_create_dev(struct vduse_dev_config *config, 
	dev->config = config_buf;

	dev->config_size = config->config_size;



	ret = vduse_dev_init_vqs(dev, config->vq_align, config->vq_num);

	if (ret)

		goto err_vqs;



	ret = idr_alloc(&vduse_idr, dev, 1, VDUSE_DEV_MAX, GFP_KERNEL);

	if (ret < 0)

		goto err_idr;
@@ -1624,14 +1721,19 @@ static int vduse_create_dev(struct vduse_dev_config *config, 
		ret = PTR_ERR(dev->dev);

		goto err_dev;

	}



	ret = vduse_dev_init_vqs(dev, config->vq_align, config->vq_num);

	if (ret)

		goto err_vqs;



	__module_get(THIS_MODULE);



	return 0;

err_vqs:

	device_destroy(vduse_class, MKDEV(MAJOR(vduse_major), dev->minor));

err_dev:

	idr_remove(&vduse_idr, dev->minor);

err_idr:

	vduse_dev_deinit_vqs(dev);

err_vqs:

	vduse_domain_destroy(dev->domain);

err_domain:

	kfree(dev->name);