Re: [RFC 09/10] vfio: Refactor dma APIs for emulated devices

[Yi Liu <yi.l.liu@xxxxxxxxx>]

On 2022/11/24 00:51, Jason Gunthorpe wrote:
> On Wed, Nov 23, 2022 at 07:01:12AM -0800, Yi Liu wrote:
> > To use group helpers instead of opening group related code in the
> > API. This prepares moving group specific code out of vfio_main.c.
> >
> > Signed-off-by: Yi Liu <yi.l.liu@xxxxxxxxx>
> > Signed-off-by: Nicolin Chen <nicolinc@xxxxxxxxxx>
> > ---
> >   drivers/vfio/container.c | 20 +++++++++++++-------
> >   drivers/vfio/vfio.h      | 32 ++++++++++++++++----------------
> >   drivers/vfio/vfio_main.c | 26 +++++++++++++++-----------
> >   3 files changed, 44 insertions(+), 34 deletions(-)
> >
> > diff --git a/drivers/vfio/container.c b/drivers/vfio/container.c
> > index 6b362d97d682..e0d11ab7229a 100644
> > --- a/drivers/vfio/container.c
> > +++ b/drivers/vfio/container.c
> > @@ -540,11 +540,13 @@ void vfio_group_unuse_container(struct vfio_group *group)
> >   	fput(group->opened_file);
> >   }
> >   
> > -int vfio_container_pin_pages(struct vfio_container *container,
> > -			     struct iommu_group *iommu_group, dma_addr_t iova,
> > -			     int npage, int prot, struct page **pages)
> > +int vfio_group_container_pin_pages(struct vfio_group *group,
> > +				   dma_addr_t iova, int npage,
> > +				   int prot, struct page **pages)
> >   {
> > +	struct vfio_container *container = group->container;
> >   	struct vfio_iommu_driver *driver = container->iommu_driver;
> > +	struct iommu_group *iommu_group = group->iommu_group;
> >   
> >   	if (npage > VFIO_PIN_PAGES_MAX_ENTRIES)
> >   		return -E2BIG;
> > @@ -555,9 +557,11 @@ int vfio_container_pin_pages(struct vfio_container *container,
> >   				      npage, prot, pages);
> >   }
> >   
> > -void vfio_container_unpin_pages(struct vfio_container *container,
> > -				dma_addr_t iova, int npage)
> > +void vfio_group_container_unpin_pages(struct vfio_group *group,
> > +				      dma_addr_t iova, int npage)
> >   {
> > +	struct vfio_container *container = group->container;
> > +
> >   	if (WARN_ON(npage <= 0 || npage > VFIO_PIN_PAGES_MAX_ENTRIES))
> >   		return;
> >   
> > @@ -565,9 +569,11 @@ void vfio_container_unpin_pages(struct vfio_container *container,
> >   						  npage);
> >   }
> >   
> > -int vfio_container_dma_rw(struct vfio_container *container, dma_addr_t iova,
> > -			  void *data, size_t len, bool write)
> > +int vfio_group_container_dma_rw(struct vfio_group *group,
> > +				dma_addr_t iova, void *data,
> > +				size_t len, bool write)
> >   {
> > +	struct vfio_container *container = group->container;
> >   	struct vfio_iommu_driver *driver = container->iommu_driver;
> >   
> >   	if (unlikely(!driver || !driver->ops->dma_rw))
> > diff --git a/drivers/vfio/vfio.h b/drivers/vfio/vfio.h
> > index 3378714a7462..d6b6bc20406b 100644
> > --- a/drivers/vfio/vfio.h
> > +++ b/drivers/vfio/vfio.h
> > @@ -122,13 +122,14 @@ int vfio_container_attach_group(struct vfio_container *container,
> >   void vfio_group_detach_container(struct vfio_group *group);
> >   void vfio_device_container_register(struct vfio_device *device);
> >   void vfio_device_container_unregister(struct vfio_device *device);
> > -int vfio_container_pin_pages(struct vfio_container *container,
> > -			     struct iommu_group *iommu_group, dma_addr_t iova,
> > -			     int npage, int prot, struct page **pages);
> > -void vfio_container_unpin_pages(struct vfio_container *container,
> > -				dma_addr_t iova, int npage);
> > -int vfio_container_dma_rw(struct vfio_container *container, dma_addr_t iova,
> > -			  void *data, size_t len, bool write);
> > +int vfio_group_container_pin_pages(struct vfio_group *group,
> > +				   dma_addr_t iova, int npage,
> > +				   int prot, struct page **pages);
> > +void vfio_group_container_unpin_pages(struct vfio_group *group,
> > +				      dma_addr_t iova, int npage);
> > +int vfio_group_container_dma_rw(struct vfio_group *group,
> > +				dma_addr_t iova, void *data,
> > +				size_t len, bool write);
> >   
> >   int __init vfio_container_init(void);
> >   void vfio_container_cleanup(void);
> > @@ -166,22 +167,21 @@ static inline void vfio_device_container_unregister(struct vfio_device *device)
> >   {
> >   }
> >   
> > -static inline int vfio_container_pin_pages(struct vfio_container *container,
> > -					   struct iommu_group *iommu_group,
> > -					   dma_addr_t iova, int npage, int prot,
> > -					   struct page **pages)
> > +static inline int vfio_group_container_pin_pages(struct vfio_group *group,
> > +						 dma_addr_t iova, int npage,
> > +						 int prot, struct page **pages)
> >   {
> >   	return -EOPNOTSUPP;
> >   }
> >   
> > -static inline void vfio_container_unpin_pages(struct vfio_container *container,
> > -					      dma_addr_t iova, int npage)
> > +static inline void vfio_group_container_unpin_pages(struct vfio_group *group,
> > +						    dma_addr_t iova, int npage)
> >   {
> >   }
> >   
> > -static inline int vfio_container_dma_rw(struct vfio_container *container,
> > -					dma_addr_t iova, void *data, size_t len,
> > -					bool write)
> > +static inline int vfio_group_container_dma_rw(struct vfio_group *group,
> > +					      dma_addr_t iova, void *data,
> > +					      size_t len, bool write)
> >   {
> >   	return -EOPNOTSUPP;
> >   }
> > diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
> > index cde258f4ea17..b6d3cb35a523 100644
> > --- a/drivers/vfio/vfio_main.c
> > +++ b/drivers/vfio/vfio_main.c
> > @@ -1925,6 +1925,11 @@ int vfio_set_irqs_validate_and_prepare(struct vfio_irq_set *hdr, int num_irqs,
> >   }
> >   EXPORT_SYMBOL(vfio_set_irqs_validate_and_prepare);
> >   
> > +static bool vfio_group_has_container(struct vfio_group *group)
> > +{
> > +	return group->container;
> > +}
>
> This should probably be
>   
>    vfio_device_has_container(struct vfio_device  *device)
>
> And it just returns false if the group code is compiled out

sure.

--
Regards,
Yi Liu