| Message ID | 161524009646.3480.6519905534709638083.stgit@gimli.home (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | vfio: Device memory DMA mapping improvements | expand |
On Mon, Mar 08, 2021 at 02:48:16PM -0700, Alex Williamson wrote: > Add a new vfio_device_ops callback to allow the bus driver to > translate a vma mapping of a vfio device fd to a pfn. Plumb through > vfio-core. Implemented for vfio-pci. > > Suggested-by: Jason Gunthorpe <jgg@nvidia.com> > Signed-off-by: Alex Williamson <alex.williamson@redhat.com> > drivers/vfio/pci/vfio_pci.c | 1 + > drivers/vfio/vfio.c | 16 ++++++++++++++++ > include/linux/vfio.h | 3 +++ > 3 files changed, 20 insertions(+) > > diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c > index 415b5109da9b..585895970e9c 100644 > +++ b/drivers/vfio/pci/vfio_pci.c > @@ -1756,6 +1756,7 @@ static const struct vfio_device_ops vfio_pci_ops = { > .mmap = vfio_pci_mmap, > .request = vfio_pci_request, > .match = vfio_pci_match, > + .vma_to_pfn = vfio_pci_bar_vma_to_pfn, > }; > > static int vfio_pci_reflck_attach(struct vfio_pci_device *vdev); > diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c > index 3a3e85a0dc3e..c47895539a1a 100644 > +++ b/drivers/vfio/vfio.c > @@ -944,6 +944,22 @@ struct vfio_device *vfio_device_get_from_vma(struct vm_area_struct *vma) > } > EXPORT_SYMBOL_GPL(vfio_device_get_from_vma); > > +int vfio_vma_to_pfn(struct vm_area_struct *vma, unsigned long *pfn) > +{ > + struct vfio_device *device; > + > + if (!vma->vm_file || vma->vm_file->f_op != &vfio_device_fops) > + return -EINVAL; > + > + device = vma->vm_file->private_data; Since the caller has the vfio_device already I would pass in the vfio_device here rather than look it up again. If you are really worried about API mis-use then use a protective assertion like this: if (WARN_ON(vma->vm_file->private_data != device)) return -EINVAL; Jason
diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c index 415b5109da9b..585895970e9c 100644 --- a/drivers/vfio/pci/vfio_pci.c +++ b/drivers/vfio/pci/vfio_pci.c @@ -1756,6 +1756,7 @@ static const struct vfio_device_ops vfio_pci_ops = { .mmap = vfio_pci_mmap, .request = vfio_pci_request, .match = vfio_pci_match, + .vma_to_pfn = vfio_pci_bar_vma_to_pfn, }; static int vfio_pci_reflck_attach(struct vfio_pci_device *vdev); diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c index 3a3e85a0dc3e..c47895539a1a 100644 --- a/drivers/vfio/vfio.c +++ b/drivers/vfio/vfio.c @@ -944,6 +944,22 @@ struct vfio_device *vfio_device_get_from_vma(struct vm_area_struct *vma) } EXPORT_SYMBOL_GPL(vfio_device_get_from_vma); +int vfio_vma_to_pfn(struct vm_area_struct *vma, unsigned long *pfn) +{ + struct vfio_device *device; + + if (!vma->vm_file || vma->vm_file->f_op != &vfio_device_fops) + return -EINVAL; + + device = vma->vm_file->private_data; + + if (unlikely(!device->ops->vma_to_pfn)) + return -EINVAL; + + return device->ops->vma_to_pfn(vma, pfn); +} +EXPORT_SYMBOL_GPL(vfio_vma_to_pfn); + static struct vfio_device *vfio_device_get_from_name(struct vfio_group *group, char *buf) { diff --git a/include/linux/vfio.h b/include/linux/vfio.h index 660b8adf90a6..dbd90d0ba713 100644 --- a/include/linux/vfio.h +++ b/include/linux/vfio.h @@ -29,6 +29,7 @@ * @match: Optional device name match callback (return: 0 for no-match, >0 for * match, -errno for abort (ex. match with insufficient or incorrect * additional args) + * @vma_to_pfn: Optional pfn from vma lookup against vma mapping device fd */ struct vfio_device_ops { char *name; @@ -43,6 +44,7 @@ struct vfio_device_ops { int (*mmap)(void *device_data, struct vm_area_struct *vma); void (*request)(void *device_data, unsigned int count); int (*match)(void *device_data, char *buf); + int (*vma_to_pfn)(struct vm_area_struct *vma, unsigned long *pfn); }; extern struct iommu_group *vfio_iommu_group_get(struct device *dev); @@ -59,6 +61,7 @@ extern void *vfio_device_data(struct vfio_device *device); extern void vfio_device_unmap_mapping_range(struct vfio_device *device, loff_t start, loff_t len); extern struct vfio_device *vfio_device_get_from_vma(struct vm_area_struct *vma); +extern int vfio_vma_to_pfn(struct vm_area_struct *vma, unsigned long *pfn); /* events for the backend driver notify callback */ enum vfio_iommu_notify_type {
Add a new vfio_device_ops callback to allow the bus driver to translate a vma mapping of a vfio device fd to a pfn. Plumb through vfio-core. Implemented for vfio-pci. Suggested-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> --- drivers/vfio/pci/vfio_pci.c | 1 + drivers/vfio/vfio.c | 16 ++++++++++++++++ include/linux/vfio.h | 3 +++ 3 files changed, 20 insertions(+)