diff options
-rw-r--r-- | include/uapi/linux/vfio.h | 31 |
1 files changed, 30 insertions, 1 deletions
diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h index fde7b1e..1c37a0e 100644 --- a/include/uapi/linux/vfio.h +++ b/include/uapi/linux/vfio.h @@ -252,6 +252,34 @@ struct vfio_region_info_cap_sparse_mmap { struct vfio_region_sparse_mmap_area areas[]; }; +/* + * The device specific type capability allows regions unique to a specific + * device or class of devices to be exposed. This helps solve the problem for + * vfio bus drivers of defining which region indexes correspond to which region + * on the device, without needing to resort to static indexes, as done by + * vfio-pci. For instance, if we were to go back in time, we might remove + * VFIO_PCI_VGA_REGION_INDEX and let vfio-pci simply define that all indexes + * greater than or equal to VFIO_PCI_NUM_REGIONS are device specific and we'd + * make a "VGA" device specific type to describe the VGA access space. This + * means that non-VGA devices wouldn't need to waste this index, and thus the + * address space associated with it due to implementation of device file + * descriptor offsets in vfio-pci. + * + * The current implementation is now part of the user ABI, so we can't use this + * for VGA, but there are other upcoming use cases, such as opregions for Intel + * IGD devices and framebuffers for vGPU devices. We missed VGA, but we'll + * use this for future additions. + * + * The structure below defines version 1 of this capability. + */ +#define VFIO_REGION_INFO_CAP_TYPE 2 + +struct vfio_region_info_cap_type { + struct vfio_info_cap_header header; + __u32 type; /* global per bus driver */ + __u32 subtype; /* type specific */ +}; + /** * VFIO_DEVICE_GET_IRQ_INFO - _IOWR(VFIO_TYPE, VFIO_BASE + 9, * struct vfio_irq_info) @@ -387,7 +415,8 @@ enum { * between described ranges are unimplemented. */ VFIO_PCI_VGA_REGION_INDEX, - VFIO_PCI_NUM_REGIONS + VFIO_PCI_NUM_REGIONS = 9 /* Fixed user ABI, region indexes >=9 use */ + /* device specific cap to define content. */ }; enum { |