With the introduction of the new object and its infrastructure, update the doc to reflect that.
Signed-off-by: Nicolin Chen nicolinc@nvidia.com --- Documentation/userspace-api/iommufd.rst | 14 ++++++++++++++ 1 file changed, 14 insertions(+)
diff --git a/Documentation/userspace-api/iommufd.rst b/Documentation/userspace-api/iommufd.rst index b0df15865dec..afca749652ee 100644 --- a/Documentation/userspace-api/iommufd.rst +++ b/Documentation/userspace-api/iommufd.rst @@ -124,6 +124,19 @@ Following IOMMUFD objects are exposed to userspace: used to allocate a vEVENTQ. Each vIOMMU can support multiple types of vEVENTS, but is confined to one vEVENTQ per vEVENTQ type.
+- IOMMUFD_OBJ_VCMDQ, representing a hardware queue as a subset of a vIOMMU's + virtualization feature for a VM to directly execute guest-issued commands to + invalidate HW cache entries holding the mappings or translations of a guest- + owned stage-1 page table. Along with this queue object, iommufd provides the + user space an mmap interface for VMM to mmap a physical MMIO region from the + host physical address space to a guest physical address space, to exclusively + control the allocated vCMDQ HW. Thus, when allocating a vCMDQ, the VMM must + request a pair of VMA info (vm_pgoff/size) for a later mmap call. The length + argument of an mmap call could be smaller than the given size for a paritial + mmap, but the given vm_pgoff (as the addr argument of the mmap call) should + never be offsetted, which also implies that the mmap will always start from + the beginning of the physical MMIO region. + All user-visible objects are destroyed via the IOMMU_DESTROY uAPI.
The diagrams below show relationships between user-visible objects and kernel @@ -270,6 +283,7 @@ User visible objects are backed by following datastructures: - iommufd_viommu for IOMMUFD_OBJ_VIOMMU. - iommufd_vdevice for IOMMUFD_OBJ_VDEVICE. - iommufd_veventq for IOMMUFD_OBJ_VEVENTQ. +- iommufd_vcmdq for IOMMUFD_OBJ_VCMDQ.
Several terminologies when looking at these datastructures: