diff mbox series

[11/21] vhost-vdpa: introduce asid based IOTLB

Message ID 20201216064818.48239-12-jasowang@redhat.com (mailing list archive)
State New, archived
Headers show
Series Control VQ support in vDPA | expand

Commit Message

Jason Wang Dec. 16, 2020, 6:48 a.m. UTC
This patch converts the vhost-vDPA device to support multiple IOTLBs
tagged via ASID via hlist. This will be used for supporting multiple
address spaces in the following patches.

Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 drivers/vhost/vdpa.c | 106 ++++++++++++++++++++++++++++++++-----------
 1 file changed, 80 insertions(+), 26 deletions(-)

Comments

Eli Cohen Dec. 29, 2020, 11:41 a.m. UTC | #1
On Wed, Dec 16, 2020 at 02:48:08PM +0800, Jason Wang wrote:
> This patch converts the vhost-vDPA device to support multiple IOTLBs
> tagged via ASID via hlist. This will be used for supporting multiple
> address spaces in the following patches.
> 
> Signed-off-by: Jason Wang <jasowang@redhat.com>
> ---
>  drivers/vhost/vdpa.c | 106 ++++++++++++++++++++++++++++++++-----------
>  1 file changed, 80 insertions(+), 26 deletions(-)
> 
> diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
> index feb6a58df22d..060d5b5b7e64 100644
> --- a/drivers/vhost/vdpa.c
> +++ b/drivers/vhost/vdpa.c
> @@ -33,13 +33,21 @@ enum {
>  
>  #define VHOST_VDPA_DEV_MAX (1U << MINORBITS)
>  
> +#define VHOST_VDPA_IOTLB_BUCKETS 16
> +
> +struct vhost_vdpa_as {
> +	struct hlist_node hash_link;
> +	struct vhost_iotlb iotlb;
> +	u32 id;
> +};
> +
>  struct vhost_vdpa {
>  	struct vhost_dev vdev;
>  	struct iommu_domain *domain;
>  	struct vhost_virtqueue *vqs;
>  	struct completion completion;
>  	struct vdpa_device *vdpa;
> -	struct vhost_iotlb *iotlb;
> +	struct hlist_head as[VHOST_VDPA_IOTLB_BUCKETS];
>  	struct device dev;
>  	struct cdev cdev;
>  	atomic_t opened;
> @@ -49,12 +57,64 @@ struct vhost_vdpa {
>  	struct eventfd_ctx *config_ctx;
>  	int in_batch;
>  	struct vdpa_iova_range range;
> +	int used_as;

This is not really used. Not in this patch and later removed.

>  };
>  
>  static DEFINE_IDA(vhost_vdpa_ida);
>  
>  static dev_t vhost_vdpa_major;
>  
> +static struct vhost_vdpa_as *asid_to_as(struct vhost_vdpa *v, u32 asid)
> +{
> +	struct hlist_head *head = &v->as[asid % VHOST_VDPA_IOTLB_BUCKETS];
> +	struct vhost_vdpa_as *as;
> +
> +	hlist_for_each_entry(as, head, hash_link)
> +		if (as->id == asid)
> +			return as;
> +
> +	return NULL;
> +}
> +
> +static struct vhost_vdpa_as *vhost_vdpa_alloc_as(struct vhost_vdpa *v, u32 asid)
> +{
> +	struct hlist_head *head = &v->as[asid % VHOST_VDPA_IOTLB_BUCKETS];
> +	struct vhost_vdpa_as *as;
> +
> +	if (asid_to_as(v, asid))
> +		return NULL;
> +
> +	as = kmalloc(sizeof(*as), GFP_KERNEL);
> +	if (!as)
> +		return NULL;
> +
> +	vhost_iotlb_init(&as->iotlb, 0, 0);
> +	as->id = asid;
> +	hlist_add_head(&as->hash_link, head);
> +	++v->used_as;
> +
> +	return as;
> +}
> +
> +static int vhost_vdpa_remove_as(struct vhost_vdpa *v, u32 asid)
> +{
> +	struct vhost_vdpa_as *as = asid_to_as(v, asid);
> +
> +	/* Remove default address space is not allowed */
> +	if (asid == 0)
> +		return -EINVAL;
> +
> +	if (!as)
> +		return -EINVAL;
> +
> +	hlist_del(&as->hash_link);
> +	vhost_iotlb_reset(&as->iotlb);
> +	kfree(as);
> +	--v->used_as;
> +
> +	return 0;
> +}
> +
>  static void handle_vq_kick(struct vhost_work *work)
>  {
>  	struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
> @@ -525,15 +585,6 @@ static void vhost_vdpa_iotlb_unmap(struct vhost_vdpa *v,
>  	}
>  }
>  
> -static void vhost_vdpa_iotlb_free(struct vhost_vdpa *v)
> -{
> -	struct vhost_iotlb *iotlb = v->iotlb;
> -
> -	vhost_vdpa_iotlb_unmap(v, iotlb, 0ULL, 0ULL - 1);
> -	kfree(v->iotlb);
> -	v->iotlb = NULL;
> -}
> -
>  static int perm_to_iommu_flags(u32 perm)
>  {
>  	int flags = 0;
> @@ -745,7 +796,8 @@ static int vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev, u32 asid,
>  	struct vhost_vdpa *v = container_of(dev, struct vhost_vdpa, vdev);
>  	struct vdpa_device *vdpa = v->vdpa;
>  	const struct vdpa_config_ops *ops = vdpa->config;
> -	struct vhost_iotlb *iotlb = v->iotlb;
> +	struct vhost_vdpa_as *as = asid_to_as(v, 0);
> +	struct vhost_iotlb *iotlb = &as->iotlb;
>  	int r = 0;
>  
>  	if (asid != 0)
> @@ -856,6 +908,13 @@ static void vhost_vdpa_set_iova_range(struct vhost_vdpa *v)
>  	}
>  }
>  
> +static void vhost_vdpa_cleanup(struct vhost_vdpa *v)
> +{
> +	vhost_dev_cleanup(&v->vdev);
> +	kfree(v->vdev.vqs);
> +	vhost_vdpa_remove_as(v, 0);
> +}
> +
>  static int vhost_vdpa_open(struct inode *inode, struct file *filep)
>  {
>  	struct vhost_vdpa *v;
> @@ -886,15 +945,12 @@ static int vhost_vdpa_open(struct inode *inode, struct file *filep)
>  	vhost_dev_init(dev, vqs, nvqs, 0, 0, 0, false,
>  		       vhost_vdpa_process_iotlb_msg);
>  
> -	v->iotlb = vhost_iotlb_alloc(0, 0);
> -	if (!v->iotlb) {
> -		r = -ENOMEM;
> -		goto err_init_iotlb;
> -	}
> +	if (!vhost_vdpa_alloc_as(v, 0))
> +		goto err_alloc_as;
>  
>  	r = vhost_vdpa_alloc_domain(v);
>  	if (r)
> -		goto err_alloc_domain;
> +		goto err_alloc_as;
>  
>  	vhost_vdpa_set_iova_range(v);
>  
> @@ -902,11 +958,8 @@ static int vhost_vdpa_open(struct inode *inode, struct file *filep)
>  
>  	return 0;
>  
> -err_alloc_domain:
> -	vhost_vdpa_iotlb_free(v);
> -err_init_iotlb:
> -	vhost_dev_cleanup(&v->vdev);
> -	kfree(vqs);
> +err_alloc_as:
> +	vhost_vdpa_cleanup(v);
>  err:
>  	atomic_dec(&v->opened);
>  	return r;
> @@ -933,12 +986,10 @@ static int vhost_vdpa_release(struct inode *inode, struct file *filep)
>  	filep->private_data = NULL;
>  	vhost_vdpa_reset(v);
>  	vhost_dev_stop(&v->vdev);
> -	vhost_vdpa_iotlb_free(v);
>  	vhost_vdpa_free_domain(v);
>  	vhost_vdpa_config_put(v);
>  	vhost_vdpa_clean_irq(v);
> -	vhost_dev_cleanup(&v->vdev);
> -	kfree(v->vdev.vqs);
> +	vhost_vdpa_cleanup(v);
>  	mutex_unlock(&d->mutex);
>  
>  	atomic_dec(&v->opened);
> @@ -1033,7 +1084,7 @@ static int vhost_vdpa_probe(struct vdpa_device *vdpa)
>  	const struct vdpa_config_ops *ops = vdpa->config;
>  	struct vhost_vdpa *v;
>  	int minor;
> -	int r;
> +	int i, r;
>  
>  	/* Only support 1 address space and 1 groups */
>  	if (vdpa->ngroups != 1 || vdpa->nas != 1)
> @@ -1085,6 +1136,9 @@ static int vhost_vdpa_probe(struct vdpa_device *vdpa)
>  	init_completion(&v->completion);
>  	vdpa_set_drvdata(vdpa, v);
>  
> +	for (i = 0; i < VHOST_VDPA_IOTLB_BUCKETS; i++)
> +		INIT_HLIST_HEAD(&v->as[i]);
> +
>  	return 0;
>  
>  err:
> -- 
> 2.25.1
>
Eli Cohen Dec. 29, 2020, 11:53 a.m. UTC | #2
On Wed, Dec 16, 2020 at 02:48:08PM +0800, Jason Wang wrote:
> This patch converts the vhost-vDPA device to support multiple IOTLBs
> tagged via ASID via hlist. This will be used for supporting multiple
> address spaces in the following patches.
> 
> Signed-off-by: Jason Wang <jasowang@redhat.com>
> ---
>  drivers/vhost/vdpa.c | 106 ++++++++++++++++++++++++++++++++-----------
>  1 file changed, 80 insertions(+), 26 deletions(-)
> 
> diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
> index feb6a58df22d..060d5b5b7e64 100644
> --- a/drivers/vhost/vdpa.c
> +++ b/drivers/vhost/vdpa.c
> @@ -33,13 +33,21 @@ enum {
>  
>  #define VHOST_VDPA_DEV_MAX (1U << MINORBITS)
>  
> +#define VHOST_VDPA_IOTLB_BUCKETS 16
> +
> +struct vhost_vdpa_as {
> +	struct hlist_node hash_link;
> +	struct vhost_iotlb iotlb;
> +	u32 id;
> +};
> +
>  struct vhost_vdpa {
>  	struct vhost_dev vdev;
>  	struct iommu_domain *domain;
>  	struct vhost_virtqueue *vqs;
>  	struct completion completion;
>  	struct vdpa_device *vdpa;
> -	struct vhost_iotlb *iotlb;
> +	struct hlist_head as[VHOST_VDPA_IOTLB_BUCKETS];
>  	struct device dev;
>  	struct cdev cdev;
>  	atomic_t opened;
> @@ -49,12 +57,64 @@ struct vhost_vdpa {
>  	struct eventfd_ctx *config_ctx;
>  	int in_batch;
>  	struct vdpa_iova_range range;
> +	int used_as;
>  };
>  
>  static DEFINE_IDA(vhost_vdpa_ida);
>  
>  static dev_t vhost_vdpa_major;
>  
> +static struct vhost_vdpa_as *asid_to_as(struct vhost_vdpa *v, u32 asid)
> +{
> +	struct hlist_head *head = &v->as[asid % VHOST_VDPA_IOTLB_BUCKETS];
> +	struct vhost_vdpa_as *as;
> +
> +	hlist_for_each_entry(as, head, hash_link)
> +		if (as->id == asid)
> +			return as;
> +
> +	return NULL;
> +}
> +
> +static struct vhost_vdpa_as *vhost_vdpa_alloc_as(struct vhost_vdpa *v, u32 asid)
> +{
> +	struct hlist_head *head = &v->as[asid % VHOST_VDPA_IOTLB_BUCKETS];
> +	struct vhost_vdpa_as *as;
> +
> +	if (asid_to_as(v, asid))
> +		return NULL;
> +
> +	as = kmalloc(sizeof(*as), GFP_KERNEL);

kzalloc()? See comment below.

> +	if (!as)
> +		return NULL;
> +
> +	vhost_iotlb_init(&as->iotlb, 0, 0);
> +	as->id = asid;
> +	hlist_add_head(&as->hash_link, head);
> +	++v->used_as;

Although you eventually ended up removing used_as, this is a bug since
you're incrementing a random value. Maybe it's better to be on the safe
side and use kzalloc() for as above.

> +
> +	return as;
> +}
> +
> +static int vhost_vdpa_remove_as(struct vhost_vdpa *v, u32 asid)
> +{
> +	struct vhost_vdpa_as *as = asid_to_as(v, asid);
> +
> +	/* Remove default address space is not allowed */
> +	if (asid == 0)
> +		return -EINVAL;
> +
> +	if (!as)
> +		return -EINVAL;
> +
> +	hlist_del(&as->hash_link);
> +	vhost_iotlb_reset(&as->iotlb);
> +	kfree(as);
> +	--v->used_as;
> +
> +	return 0;
> +}
> +
>  static void handle_vq_kick(struct vhost_work *work)
>  {
>  	struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
> @@ -525,15 +585,6 @@ static void vhost_vdpa_iotlb_unmap(struct vhost_vdpa *v,
>  	}
>  }
>  
> -static void vhost_vdpa_iotlb_free(struct vhost_vdpa *v)
> -{
> -	struct vhost_iotlb *iotlb = v->iotlb;
> -
> -	vhost_vdpa_iotlb_unmap(v, iotlb, 0ULL, 0ULL - 1);
> -	kfree(v->iotlb);
> -	v->iotlb = NULL;
> -}
> -
>  static int perm_to_iommu_flags(u32 perm)
>  {
>  	int flags = 0;
> @@ -745,7 +796,8 @@ static int vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev, u32 asid,
>  	struct vhost_vdpa *v = container_of(dev, struct vhost_vdpa, vdev);
>  	struct vdpa_device *vdpa = v->vdpa;
>  	const struct vdpa_config_ops *ops = vdpa->config;
> -	struct vhost_iotlb *iotlb = v->iotlb;
> +	struct vhost_vdpa_as *as = asid_to_as(v, 0);
> +	struct vhost_iotlb *iotlb = &as->iotlb;
>  	int r = 0;
>  
>  	if (asid != 0)
> @@ -856,6 +908,13 @@ static void vhost_vdpa_set_iova_range(struct vhost_vdpa *v)
>  	}
>  }
>  
> +static void vhost_vdpa_cleanup(struct vhost_vdpa *v)
> +{
> +	vhost_dev_cleanup(&v->vdev);
> +	kfree(v->vdev.vqs);
> +	vhost_vdpa_remove_as(v, 0);
> +}
> +
>  static int vhost_vdpa_open(struct inode *inode, struct file *filep)
>  {
>  	struct vhost_vdpa *v;
> @@ -886,15 +945,12 @@ static int vhost_vdpa_open(struct inode *inode, struct file *filep)
>  	vhost_dev_init(dev, vqs, nvqs, 0, 0, 0, false,
>  		       vhost_vdpa_process_iotlb_msg);
>  
> -	v->iotlb = vhost_iotlb_alloc(0, 0);
> -	if (!v->iotlb) {
> -		r = -ENOMEM;
> -		goto err_init_iotlb;
> -	}
> +	if (!vhost_vdpa_alloc_as(v, 0))
> +		goto err_alloc_as;
>  
>  	r = vhost_vdpa_alloc_domain(v);
>  	if (r)
> -		goto err_alloc_domain;
> +		goto err_alloc_as;
>  
>  	vhost_vdpa_set_iova_range(v);
>  
> @@ -902,11 +958,8 @@ static int vhost_vdpa_open(struct inode *inode, struct file *filep)
>  
>  	return 0;
>  
> -err_alloc_domain:
> -	vhost_vdpa_iotlb_free(v);
> -err_init_iotlb:
> -	vhost_dev_cleanup(&v->vdev);
> -	kfree(vqs);
> +err_alloc_as:
> +	vhost_vdpa_cleanup(v);
>  err:
>  	atomic_dec(&v->opened);
>  	return r;
> @@ -933,12 +986,10 @@ static int vhost_vdpa_release(struct inode *inode, struct file *filep)
>  	filep->private_data = NULL;
>  	vhost_vdpa_reset(v);
>  	vhost_dev_stop(&v->vdev);
> -	vhost_vdpa_iotlb_free(v);
>  	vhost_vdpa_free_domain(v);
>  	vhost_vdpa_config_put(v);
>  	vhost_vdpa_clean_irq(v);
> -	vhost_dev_cleanup(&v->vdev);
> -	kfree(v->vdev.vqs);
> +	vhost_vdpa_cleanup(v);
>  	mutex_unlock(&d->mutex);
>  
>  	atomic_dec(&v->opened);
> @@ -1033,7 +1084,7 @@ static int vhost_vdpa_probe(struct vdpa_device *vdpa)
>  	const struct vdpa_config_ops *ops = vdpa->config;
>  	struct vhost_vdpa *v;
>  	int minor;
> -	int r;
> +	int i, r;
>  
>  	/* Only support 1 address space and 1 groups */
>  	if (vdpa->ngroups != 1 || vdpa->nas != 1)
> @@ -1085,6 +1136,9 @@ static int vhost_vdpa_probe(struct vdpa_device *vdpa)
>  	init_completion(&v->completion);
>  	vdpa_set_drvdata(vdpa, v);
>  
> +	for (i = 0; i < VHOST_VDPA_IOTLB_BUCKETS; i++)
> +		INIT_HLIST_HEAD(&v->as[i]);
> +
>  	return 0;
>  
>  err:
> -- 
> 2.25.1
>
Eli Cohen Dec. 29, 2020, 12:05 p.m. UTC | #3
On Wed, Dec 16, 2020 at 02:48:08PM +0800, Jason Wang wrote:
> This patch converts the vhost-vDPA device to support multiple IOTLBs
> tagged via ASID via hlist. This will be used for supporting multiple
> address spaces in the following patches.
> 
> Signed-off-by: Jason Wang <jasowang@redhat.com>
> ---
>  drivers/vhost/vdpa.c | 106 ++++++++++++++++++++++++++++++++-----------
>  1 file changed, 80 insertions(+), 26 deletions(-)
> 
> diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
> index feb6a58df22d..060d5b5b7e64 100644
> --- a/drivers/vhost/vdpa.c
> +++ b/drivers/vhost/vdpa.c
> @@ -33,13 +33,21 @@ enum {
>  
>  #define VHOST_VDPA_DEV_MAX (1U << MINORBITS)
>  
> +#define VHOST_VDPA_IOTLB_BUCKETS 16
> +
> +struct vhost_vdpa_as {
> +	struct hlist_node hash_link;
> +	struct vhost_iotlb iotlb;
> +	u32 id;
> +};
> +
>  struct vhost_vdpa {
>  	struct vhost_dev vdev;
>  	struct iommu_domain *domain;
>  	struct vhost_virtqueue *vqs;
>  	struct completion completion;
>  	struct vdpa_device *vdpa;
> -	struct vhost_iotlb *iotlb;
> +	struct hlist_head as[VHOST_VDPA_IOTLB_BUCKETS];
>  	struct device dev;
>  	struct cdev cdev;
>  	atomic_t opened;
> @@ -49,12 +57,64 @@ struct vhost_vdpa {
>  	struct eventfd_ctx *config_ctx;
>  	int in_batch;
>  	struct vdpa_iova_range range;
> +	int used_as;
>  };
>  
>  static DEFINE_IDA(vhost_vdpa_ida);
>  
>  static dev_t vhost_vdpa_major;
>  
> +static struct vhost_vdpa_as *asid_to_as(struct vhost_vdpa *v, u32 asid)
> +{
> +	struct hlist_head *head = &v->as[asid % VHOST_VDPA_IOTLB_BUCKETS];
> +	struct vhost_vdpa_as *as;
> +
> +	hlist_for_each_entry(as, head, hash_link)
> +		if (as->id == asid)
> +			return as;
> +
> +	return NULL;
> +}
> +
> +static struct vhost_vdpa_as *vhost_vdpa_alloc_as(struct vhost_vdpa *v, u32 asid)
> +{
> +	struct hlist_head *head = &v->as[asid % VHOST_VDPA_IOTLB_BUCKETS];
> +	struct vhost_vdpa_as *as;
> +
> +	if (asid_to_as(v, asid))
> +		return NULL;
> +
> +	as = kmalloc(sizeof(*as), GFP_KERNEL);
> +	if (!as)
> +		return NULL;
> +
> +	vhost_iotlb_init(&as->iotlb, 0, 0);
> +	as->id = asid;
> +	hlist_add_head(&as->hash_link, head);
> +	++v->used_as;
> +
> +	return as;
> +}
> +
> +static int vhost_vdpa_remove_as(struct vhost_vdpa *v, u32 asid)

The return value is never interpreted. I think it should either be made
void or return values checked.

> +{
> +	struct vhost_vdpa_as *as = asid_to_as(v, asid);
> +
> +	/* Remove default address space is not allowed */
> +	if (asid == 0)
> +		return -EINVAL;

Can you explain why? I think you have a memory leak due to this as no
one will ever free as with id 0.

> +
> +	if (!as)
> +		return -EINVAL;
> +
> +	hlist_del(&as->hash_link);
> +	vhost_iotlb_reset(&as->iotlb);
> +	kfree(as);
> +	--v->used_as;
> +
> +	return 0;
> +}
> +
>  static void handle_vq_kick(struct vhost_work *work)
>  {
>  	struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
> @@ -525,15 +585,6 @@ static void vhost_vdpa_iotlb_unmap(struct vhost_vdpa *v,
>  	}
>  }
>  
> -static void vhost_vdpa_iotlb_free(struct vhost_vdpa *v)
> -{
> -	struct vhost_iotlb *iotlb = v->iotlb;
> -
> -	vhost_vdpa_iotlb_unmap(v, iotlb, 0ULL, 0ULL - 1);
> -	kfree(v->iotlb);
> -	v->iotlb = NULL;
> -}
> -
>  static int perm_to_iommu_flags(u32 perm)
>  {
>  	int flags = 0;
> @@ -745,7 +796,8 @@ static int vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev, u32 asid,
>  	struct vhost_vdpa *v = container_of(dev, struct vhost_vdpa, vdev);
>  	struct vdpa_device *vdpa = v->vdpa;
>  	const struct vdpa_config_ops *ops = vdpa->config;
> -	struct vhost_iotlb *iotlb = v->iotlb;
> +	struct vhost_vdpa_as *as = asid_to_as(v, 0);
> +	struct vhost_iotlb *iotlb = &as->iotlb;
>  	int r = 0;
>  
>  	if (asid != 0)
> @@ -856,6 +908,13 @@ static void vhost_vdpa_set_iova_range(struct vhost_vdpa *v)
>  	}
>  }
>  
> +static void vhost_vdpa_cleanup(struct vhost_vdpa *v)
> +{
> +	vhost_dev_cleanup(&v->vdev);
> +	kfree(v->vdev.vqs);
> +	vhost_vdpa_remove_as(v, 0);
> +}
> +
>  static int vhost_vdpa_open(struct inode *inode, struct file *filep)
>  {
>  	struct vhost_vdpa *v;
> @@ -886,15 +945,12 @@ static int vhost_vdpa_open(struct inode *inode, struct file *filep)
>  	vhost_dev_init(dev, vqs, nvqs, 0, 0, 0, false,
>  		       vhost_vdpa_process_iotlb_msg);
>  
> -	v->iotlb = vhost_iotlb_alloc(0, 0);
> -	if (!v->iotlb) {
> -		r = -ENOMEM;
> -		goto err_init_iotlb;
> -	}
> +	if (!vhost_vdpa_alloc_as(v, 0))
> +		goto err_alloc_as;
>  
>  	r = vhost_vdpa_alloc_domain(v);
>  	if (r)
> -		goto err_alloc_domain;
> +		goto err_alloc_as;
>  
>  	vhost_vdpa_set_iova_range(v);
>  
> @@ -902,11 +958,8 @@ static int vhost_vdpa_open(struct inode *inode, struct file *filep)
>  
>  	return 0;
>  
> -err_alloc_domain:
> -	vhost_vdpa_iotlb_free(v);
> -err_init_iotlb:
> -	vhost_dev_cleanup(&v->vdev);
> -	kfree(vqs);
> +err_alloc_as:
> +	vhost_vdpa_cleanup(v);
>  err:
>  	atomic_dec(&v->opened);
>  	return r;
> @@ -933,12 +986,10 @@ static int vhost_vdpa_release(struct inode *inode, struct file *filep)
>  	filep->private_data = NULL;
>  	vhost_vdpa_reset(v);
>  	vhost_dev_stop(&v->vdev);
> -	vhost_vdpa_iotlb_free(v);
>  	vhost_vdpa_free_domain(v);
>  	vhost_vdpa_config_put(v);
>  	vhost_vdpa_clean_irq(v);
> -	vhost_dev_cleanup(&v->vdev);
> -	kfree(v->vdev.vqs);
> +	vhost_vdpa_cleanup(v);
>  	mutex_unlock(&d->mutex);
>  
>  	atomic_dec(&v->opened);
> @@ -1033,7 +1084,7 @@ static int vhost_vdpa_probe(struct vdpa_device *vdpa)
>  	const struct vdpa_config_ops *ops = vdpa->config;
>  	struct vhost_vdpa *v;
>  	int minor;
> -	int r;
> +	int i, r;
>  
>  	/* Only support 1 address space and 1 groups */
>  	if (vdpa->ngroups != 1 || vdpa->nas != 1)
> @@ -1085,6 +1136,9 @@ static int vhost_vdpa_probe(struct vdpa_device *vdpa)
>  	init_completion(&v->completion);
>  	vdpa_set_drvdata(vdpa, v);
>  
> +	for (i = 0; i < VHOST_VDPA_IOTLB_BUCKETS; i++)
> +		INIT_HLIST_HEAD(&v->as[i]);
> +
>  	return 0;
>  
>  err:
> -- 
> 2.25.1
>
Jason Wang Dec. 30, 2020, 6:23 a.m. UTC | #4
On 2020/12/29 下午7:41, Eli Cohen wrote:
> On Wed, Dec 16, 2020 at 02:48:08PM +0800, Jason Wang wrote:
>> This patch converts the vhost-vDPA device to support multiple IOTLBs
>> tagged via ASID via hlist. This will be used for supporting multiple
>> address spaces in the following patches.
>>
>> Signed-off-by: Jason Wang <jasowang@redhat.com>
>> ---
>>   drivers/vhost/vdpa.c | 106 ++++++++++++++++++++++++++++++++-----------
>>   1 file changed, 80 insertions(+), 26 deletions(-)
>>
>> diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
>> index feb6a58df22d..060d5b5b7e64 100644
>> --- a/drivers/vhost/vdpa.c
>> +++ b/drivers/vhost/vdpa.c
>> @@ -33,13 +33,21 @@ enum {
>>   
>>   #define VHOST_VDPA_DEV_MAX (1U << MINORBITS)
>>   
>> +#define VHOST_VDPA_IOTLB_BUCKETS 16
>> +
>> +struct vhost_vdpa_as {
>> +	struct hlist_node hash_link;
>> +	struct vhost_iotlb iotlb;
>> +	u32 id;
>> +};
>> +
>>   struct vhost_vdpa {
>>   	struct vhost_dev vdev;
>>   	struct iommu_domain *domain;
>>   	struct vhost_virtqueue *vqs;
>>   	struct completion completion;
>>   	struct vdpa_device *vdpa;
>> -	struct vhost_iotlb *iotlb;
>> +	struct hlist_head as[VHOST_VDPA_IOTLB_BUCKETS];
>>   	struct device dev;
>>   	struct cdev cdev;
>>   	atomic_t opened;
>> @@ -49,12 +57,64 @@ struct vhost_vdpa {
>>   	struct eventfd_ctx *config_ctx;
>>   	int in_batch;
>>   	struct vdpa_iova_range range;
>> +	int used_as;
> This is not really used. Not in this patch and later removed.


Right, will remove this.

Thanks
Jason Wang Dec. 30, 2020, 6:33 a.m. UTC | #5
On 2020/12/29 下午8:05, Eli Cohen wrote:
>> +
>> +static int vhost_vdpa_remove_as(struct vhost_vdpa *v, u32 asid)
> The return value is never interpreted. I think it should either be made
> void or return values checked.


Right, will make it void.


>
>> +{
>> +	struct vhost_vdpa_as *as = asid_to_as(v, asid);
>> +
>> +	/* Remove default address space is not allowed */
>> +	if (asid == 0)
>> +		return -EINVAL;
> Can you explain why? I think you have a memory leak due to this as no
> one will ever free as with id 0.
>

Looks like a bug. Will remove this.

Thanks
Jason Wang Dec. 30, 2020, 6:34 a.m. UTC | #6
On 2020/12/29 下午7:53, Eli Cohen wrote:
>> +
>> +static struct vhost_vdpa_as *vhost_vdpa_alloc_as(struct vhost_vdpa *v, u32 asid)
>> +{
>> +	struct hlist_head *head = &v->as[asid % VHOST_VDPA_IOTLB_BUCKETS];
>> +	struct vhost_vdpa_as *as;
>> +
>> +	if (asid_to_as(v, asid))
>> +		return NULL;
>> +
>> +	as = kmalloc(sizeof(*as), GFP_KERNEL);
> kzalloc()? See comment below.
>
>> +	if (!as)
>> +		return NULL;
>> +
>> +	vhost_iotlb_init(&as->iotlb, 0, 0);
>> +	as->id = asid;
>> +	hlist_add_head(&as->hash_link, head);
>> +	++v->used_as;
> Although you eventually ended up removing used_as, this is a bug since
> you're incrementing a random value. Maybe it's better to be on the safe
> side and use kzalloc() for as above.


Yes and used_as needs to be removed.

Thanks



>
diff mbox series

Patch

diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index feb6a58df22d..060d5b5b7e64 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -33,13 +33,21 @@  enum {
 
 #define VHOST_VDPA_DEV_MAX (1U << MINORBITS)
 
+#define VHOST_VDPA_IOTLB_BUCKETS 16
+
+struct vhost_vdpa_as {
+	struct hlist_node hash_link;
+	struct vhost_iotlb iotlb;
+	u32 id;
+};
+
 struct vhost_vdpa {
 	struct vhost_dev vdev;
 	struct iommu_domain *domain;
 	struct vhost_virtqueue *vqs;
 	struct completion completion;
 	struct vdpa_device *vdpa;
-	struct vhost_iotlb *iotlb;
+	struct hlist_head as[VHOST_VDPA_IOTLB_BUCKETS];
 	struct device dev;
 	struct cdev cdev;
 	atomic_t opened;
@@ -49,12 +57,64 @@  struct vhost_vdpa {
 	struct eventfd_ctx *config_ctx;
 	int in_batch;
 	struct vdpa_iova_range range;
+	int used_as;
 };
 
 static DEFINE_IDA(vhost_vdpa_ida);
 
 static dev_t vhost_vdpa_major;
 
+static struct vhost_vdpa_as *asid_to_as(struct vhost_vdpa *v, u32 asid)
+{
+	struct hlist_head *head = &v->as[asid % VHOST_VDPA_IOTLB_BUCKETS];
+	struct vhost_vdpa_as *as;
+
+	hlist_for_each_entry(as, head, hash_link)
+		if (as->id == asid)
+			return as;
+
+	return NULL;
+}
+
+static struct vhost_vdpa_as *vhost_vdpa_alloc_as(struct vhost_vdpa *v, u32 asid)
+{
+	struct hlist_head *head = &v->as[asid % VHOST_VDPA_IOTLB_BUCKETS];
+	struct vhost_vdpa_as *as;
+
+	if (asid_to_as(v, asid))
+		return NULL;
+
+	as = kmalloc(sizeof(*as), GFP_KERNEL);
+	if (!as)
+		return NULL;
+
+	vhost_iotlb_init(&as->iotlb, 0, 0);
+	as->id = asid;
+	hlist_add_head(&as->hash_link, head);
+	++v->used_as;
+
+	return as;
+}
+
+static int vhost_vdpa_remove_as(struct vhost_vdpa *v, u32 asid)
+{
+	struct vhost_vdpa_as *as = asid_to_as(v, asid);
+
+	/* Remove default address space is not allowed */
+	if (asid == 0)
+		return -EINVAL;
+
+	if (!as)
+		return -EINVAL;
+
+	hlist_del(&as->hash_link);
+	vhost_iotlb_reset(&as->iotlb);
+	kfree(as);
+	--v->used_as;
+
+	return 0;
+}
+
 static void handle_vq_kick(struct vhost_work *work)
 {
 	struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
@@ -525,15 +585,6 @@  static void vhost_vdpa_iotlb_unmap(struct vhost_vdpa *v,
 	}
 }
 
-static void vhost_vdpa_iotlb_free(struct vhost_vdpa *v)
-{
-	struct vhost_iotlb *iotlb = v->iotlb;
-
-	vhost_vdpa_iotlb_unmap(v, iotlb, 0ULL, 0ULL - 1);
-	kfree(v->iotlb);
-	v->iotlb = NULL;
-}
-
 static int perm_to_iommu_flags(u32 perm)
 {
 	int flags = 0;
@@ -745,7 +796,8 @@  static int vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev, u32 asid,
 	struct vhost_vdpa *v = container_of(dev, struct vhost_vdpa, vdev);
 	struct vdpa_device *vdpa = v->vdpa;
 	const struct vdpa_config_ops *ops = vdpa->config;
-	struct vhost_iotlb *iotlb = v->iotlb;
+	struct vhost_vdpa_as *as = asid_to_as(v, 0);
+	struct vhost_iotlb *iotlb = &as->iotlb;
 	int r = 0;
 
 	if (asid != 0)
@@ -856,6 +908,13 @@  static void vhost_vdpa_set_iova_range(struct vhost_vdpa *v)
 	}
 }
 
+static void vhost_vdpa_cleanup(struct vhost_vdpa *v)
+{
+	vhost_dev_cleanup(&v->vdev);
+	kfree(v->vdev.vqs);
+	vhost_vdpa_remove_as(v, 0);
+}
+
 static int vhost_vdpa_open(struct inode *inode, struct file *filep)
 {
 	struct vhost_vdpa *v;
@@ -886,15 +945,12 @@  static int vhost_vdpa_open(struct inode *inode, struct file *filep)
 	vhost_dev_init(dev, vqs, nvqs, 0, 0, 0, false,
 		       vhost_vdpa_process_iotlb_msg);
 
-	v->iotlb = vhost_iotlb_alloc(0, 0);
-	if (!v->iotlb) {
-		r = -ENOMEM;
-		goto err_init_iotlb;
-	}
+	if (!vhost_vdpa_alloc_as(v, 0))
+		goto err_alloc_as;
 
 	r = vhost_vdpa_alloc_domain(v);
 	if (r)
-		goto err_alloc_domain;
+		goto err_alloc_as;
 
 	vhost_vdpa_set_iova_range(v);
 
@@ -902,11 +958,8 @@  static int vhost_vdpa_open(struct inode *inode, struct file *filep)
 
 	return 0;
 
-err_alloc_domain:
-	vhost_vdpa_iotlb_free(v);
-err_init_iotlb:
-	vhost_dev_cleanup(&v->vdev);
-	kfree(vqs);
+err_alloc_as:
+	vhost_vdpa_cleanup(v);
 err:
 	atomic_dec(&v->opened);
 	return r;
@@ -933,12 +986,10 @@  static int vhost_vdpa_release(struct inode *inode, struct file *filep)
 	filep->private_data = NULL;
 	vhost_vdpa_reset(v);
 	vhost_dev_stop(&v->vdev);
-	vhost_vdpa_iotlb_free(v);
 	vhost_vdpa_free_domain(v);
 	vhost_vdpa_config_put(v);
 	vhost_vdpa_clean_irq(v);
-	vhost_dev_cleanup(&v->vdev);
-	kfree(v->vdev.vqs);
+	vhost_vdpa_cleanup(v);
 	mutex_unlock(&d->mutex);
 
 	atomic_dec(&v->opened);
@@ -1033,7 +1084,7 @@  static int vhost_vdpa_probe(struct vdpa_device *vdpa)
 	const struct vdpa_config_ops *ops = vdpa->config;
 	struct vhost_vdpa *v;
 	int minor;
-	int r;
+	int i, r;
 
 	/* Only support 1 address space and 1 groups */
 	if (vdpa->ngroups != 1 || vdpa->nas != 1)
@@ -1085,6 +1136,9 @@  static int vhost_vdpa_probe(struct vdpa_device *vdpa)
 	init_completion(&v->completion);
 	vdpa_set_drvdata(vdpa, v);
 
+	for (i = 0; i < VHOST_VDPA_IOTLB_BUCKETS; i++)
+		INIT_HLIST_HEAD(&v->as[i]);
+
 	return 0;
 
 err: