Summary
Create a new IOMMU object in the kernel.
Declaration
#include <zircon/syscalls.h>
zx_status_t zx_iommu_create(zx_handle_t resource,
uint32_t type,
const void* desc,
size_t desc_size,
zx_handle_t* out);
Description
zx_iommu_create() creates a new object in the kernel representing an IOMMU device.
The value of type determines the interpretation of desc. See below for details about the values of type.
Upon success, a handle for the new IOMMU is returned. This handle will have rights
ZX_RIGHT_DUPLICATE and ZX_RIGHT_TRANSFER.
type = ZX_IOMMU_TYPE_DUMMY
This type represents a no-op IOMMU. It provides no hardware-level protections against unauthorized access to memory. It does allow pinning of physical memory pages, to prevent the reuse of a page until the driver using the page says it is done with it.
desc must be a valid pointer to a value of type zx_iommu_desc_dummy_t.
desc_size must be sizeof(zx_iommu_desc_dummy_t).
Rights
resource must have resource kind ZX_RSRC_KIND_SYSTEM and resource base
ZX_RSRC_SYSTEM_IOMMU_BASE.
Return value
zx_iommu_create() returns ZX_OK and a handle to the new IOMMU
(via out) on success. In the event of failure, a negative error value
is returned.
Errors
ZX_ERR_BAD_HANDLE resource is not a valid handle.
ZX_ERR_WRONG_TYPE resource is not a resource handle.
ZX_ERR_ACCESS_DENIED resource handle does not have sufficient privileges.
ZX_ERR_NOT_SUPPORTED type is not a defined value or is not
supported on this system.
ZX_ERR_INVALID_ARGS desc_size is larger than ZX_IOMMU_MAX_DESC_LEN,
desc is an invalid pointer, out is an invalid pointer, or the contents of
desc are not valid for the given type.
ZX_ERR_NO_MEMORY Failure due to lack of memory.
There is no good way for userspace to handle this (unlikely) error.
In a future build this error will no longer occur.