Re: [PATCH V3 2/3] vhost: vdpa: report iova range

[Eli Cohen]

On Sun, Oct 25, 2020 at 11:32:39AM +0200, Eli Cohen wrote:

Ignore this. I did not notice it's v3. For some reason I don't see V4 of
this patch in my mailbox.

Anyways, for V4:

Reviewed-by: Eli Cohen <elic@xxxxxxxxxx>

> On Fri, Oct 23, 2020 at 10:24:53AM +0800, Jason Wang wrote

> > This patch introduces a new ioctl for vhost-vdpa device that can
> > report the iova range by the device.
> > 
> > For device that implements get_iova_range() method, we fetch it from
> > the vDPA device. If device doesn't implement get_iova_range() but
> > depends on platform IOMMU, we will query via DOMAIN_ATTR_GEOMETRY,
> > otherwise [0, ULLONG_MAX] is assumed.
> > 
> > For safety, this patch also rules out the map request which is not in
> > the valid range.
> > 
> > Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
> > ---
> >  drivers/vhost/vdpa.c             | 40 ++++++++++++++++++++++++++++++++
> >  include/uapi/linux/vhost.h       |  4 ++++
> >  include/uapi/linux/vhost_types.h |  9 +++++++
> >  3 files changed, 53 insertions(+)
> > 
> > diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
> > index a2dbc85e0b0d..562ed99116d1 100644
> > --- a/drivers/vhost/vdpa.c
> > +++ b/drivers/vhost/vdpa.c
> > @@ -47,6 +47,7 @@ struct vhost_vdpa {
> >  	int minor;
> >  	struct eventfd_ctx *config_ctx;
> >  	int in_batch;
> > +	struct vdpa_iova_range range;
> >  };
> >  
> >  static DEFINE_IDA(vhost_vdpa_ida);
> > @@ -337,6 +338,16 @@ static long vhost_vdpa_set_config_call(struct vhost_vdpa *v, u32 __user *argp)
> >  	return 0;
> >  }
> >  
> > +static long vhost_vdpa_get_iova_range(struct vhost_vdpa *v, u32 __user *argp)
> > +{
> > +	struct vhost_vdpa_iova_range range = {
> > +		.first = v->range.first,
> > +		.last = v->range.last,
> > +	};
> > +
> > +	return copy_to_user(argp, &range, sizeof(range));
> > +}
> > +
> >  static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd,
> >  				   void __user *argp)
> >  {
> > @@ -470,6 +481,8 @@ static long vhost_vdpa_unlocked_ioctl(struct file *filep,
> >  	case VHOST_GET_BACKEND_FEATURES:
> >  		features = VHOST_VDPA_BACKEND_FEATURES;
> >  		r = copy_to_user(featurep, &features, sizeof(features));
> 
> missing break statement.
> 
> > +	case VHOST_VDPA_GET_IOVA_RANGE:
> > +		r = vhost_vdpa_get_iova_range(v, argp);
> >  		break;
> >  	default:
> >  		r = vhost_dev_ioctl(&v->vdev, cmd, argp);
> > @@ -597,6 +610,10 @@ static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
> >  	long pinned;
> >  	int ret = 0;
> >  
> > +	if (msg->iova < v->range.first ||
> > +	    msg->iova + msg->size - 1 > v->range.last)
> > +		return -EINVAL;
> > +
> >  	if (vhost_iotlb_itree_first(iotlb, msg->iova,
> >  				    msg->iova + msg->size - 1))
> >  		return -EEXIST;
> > @@ -783,6 +800,27 @@ static void vhost_vdpa_free_domain(struct vhost_vdpa *v)
> >  	v->domain = NULL;
> >  }
> >  
> > +static void vhost_vdpa_set_iova_range(struct vhost_vdpa *v)
> > +{
> > +	struct vdpa_iova_range *range = &v->range;
> > +	struct iommu_domain_geometry geo;
> > +	struct vdpa_device *vdpa = v->vdpa;
> > +	const struct vdpa_config_ops *ops = vdpa->config;
> > +
> > +	if (ops->get_iova_range) {
> > +		*range = ops->get_iova_range(vdpa);
> > +	} else if (v->domain &&
> > +		   !iommu_domain_get_attr(v->domain,
> > +		   DOMAIN_ATTR_GEOMETRY, &geo) &&
> > +		   geo.force_aperture) {
> > +		range->first = geo.aperture_start;
> > +		range->last = geo.aperture_end;
> > +	} else {
> > +		range->first = 0;
> > +		range->last = ULLONG_MAX;
> > +	}
> > +}
> > +
> >  static int vhost_vdpa_open(struct inode *inode, struct file *filep)
> >  {
> >  	struct vhost_vdpa *v;
> > @@ -823,6 +861,8 @@ static int vhost_vdpa_open(struct inode *inode, struct file *filep)
> >  	if (r)
> >  		goto err_init_iotlb;
> >  
> > +	vhost_vdpa_set_iova_range(v);
> > +
> >  	filep->private_data = v;
> >  
> >  	return 0;
> > diff --git a/include/uapi/linux/vhost.h b/include/uapi/linux/vhost.h
> > index 75232185324a..c998860d7bbc 100644
> > --- a/include/uapi/linux/vhost.h
> > +++ b/include/uapi/linux/vhost.h
> > @@ -146,4 +146,8 @@
> >  
> >  /* Set event fd for config interrupt*/
> >  #define VHOST_VDPA_SET_CONFIG_CALL	_IOW(VHOST_VIRTIO, 0x77, int)
> > +
> > +/* Get the valid iova range */
> > +#define VHOST_VDPA_GET_IOVA_RANGE	_IOR(VHOST_VIRTIO, 0x78, \
> > +					     struct vhost_vdpa_iova_range)
> >  #endif
> > diff --git a/include/uapi/linux/vhost_types.h b/include/uapi/linux/vhost_types.h
> > index 9a269a88a6ff..f7f6a3a28977 100644
> > --- a/include/uapi/linux/vhost_types.h
> > +++ b/include/uapi/linux/vhost_types.h
> > @@ -138,6 +138,15 @@ struct vhost_vdpa_config {
> >  	__u8 buf[0];
> >  };
> >  
> > +/* vhost vdpa IOVA range
> > + * @first: First address that can be mapped by vhost-vDPA
> > + * @last: Last address that can be mapped by vhost-vDPA
> > + */
> > +struct vhost_vdpa_iova_range {
> > +	__u64 first;
> > +	__u64 last;
> > +};
> > +
> >  /* Feature bits */
> >  /* Log all write descriptors. Can be changed while device is active. */
> >  #define VHOST_F_LOG_ALL 26
> > -- 
> > 2.20.1
> >