[RFC v10 02/25] header file update VFIO/IOMMU vSVA APIs kernel 5.9-rc2

[Liu Yi L]

The kernel uapi/linux/iommu.h header file includes the
extensions for vSVA support. e.g. bind gpasid, iommu
fault report related user structures and etc.

This commit updates kernel headers from the below branch:
https://github.com/luxis1999/linux-vsva.git vsva-linux-5.9-rc2-v7

Note: this should be replaced with a full header files update when
the vSVA uPAPI is stable.

Cc: Kevin Tian <kevin.tian@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Yi Sun <yi.y.sun@linux.intel.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Cornelia Huck <cohuck@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Liu Yi L <yi.l.liu@intel.com>
---
 linux-headers/linux/iommu.h | 420 ++++++++++++++++++++++++++++++++++++++++++++
 linux-headers/linux/vfio.h  | 103 ++++++++++-
 2 files changed, 522 insertions(+), 1 deletion(-)
 create mode 100644 linux-headers/linux/iommu.h

diff --git a/linux-headers/linux/iommu.h b/linux-headers/linux/iommu.h
new file mode 100644
index 0000000..be6cce1
--- /dev/null
+++ b/linux-headers/linux/iommu.h
@@ -0,0 +1,420 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * IOMMU user API definitions
+ */
+
+#ifndef _IOMMU_H
+#define _IOMMU_H
+
+#include <linux/types.h>
+
+#define IOMMU_FAULT_PERM_READ  (1 << 0) /* read */
+#define IOMMU_FAULT_PERM_WRITE (1 << 1) /* write */
+#define IOMMU_FAULT_PERM_EXEC  (1 << 2) /* exec */
+#define IOMMU_FAULT_PERM_PRIV  (1 << 3) /* privileged */
+
+/* Generic fault types, can be expanded IRQ remapping fault */
+enum iommu_fault_type {
+       IOMMU_FAULT_DMA_UNRECOV = 1,    /* unrecoverable fault */
+       IOMMU_FAULT_PAGE_REQ,           /* page request fault */
+};
+
+enum iommu_fault_reason {
+       IOMMU_FAULT_REASON_UNKNOWN = 0,
+
+       /* Could not access the PASID table (fetch caused external abort) */
+       IOMMU_FAULT_REASON_PASID_FETCH,
+
+       /* PASID entry is invalid or has configuration errors */
+       IOMMU_FAULT_REASON_BAD_PASID_ENTRY,
+
+       /*
+        * PASID is out of range (e.g. exceeds the maximum PASID
+        * supported by the IOMMU) or disabled.
+        */
+       IOMMU_FAULT_REASON_PASID_INVALID,
+
+       /*
+        * An external abort occurred fetching (or updating) a translation
+        * table descriptor
+        */
+       IOMMU_FAULT_REASON_WALK_EABT,
+
+       /*
+        * Could not access the page table entry (Bad address),
+        * actual translation fault
+        */
+       IOMMU_FAULT_REASON_PTE_FETCH,
+
+       /* Protection flag check failed */
+       IOMMU_FAULT_REASON_PERMISSION,
+
+       /* access flag check failed */
+       IOMMU_FAULT_REASON_ACCESS,
+
+       /* Output address of a translation stage caused Address Size fault */
+       IOMMU_FAULT_REASON_OOR_ADDRESS,
+};
+
+/**
+ * struct iommu_fault_unrecoverable - Unrecoverable fault data
+ * @reason: reason of the fault, from &enum iommu_fault_reason
+ * @flags: parameters of this fault (IOMMU_FAULT_UNRECOV_* values)
+ * @pasid: Process Address Space ID
+ * @perm: requested permission access using by the incoming transaction
+ *        (IOMMU_FAULT_PERM_* values)
+ * @addr: offending page address
+ * @fetch_addr: address that caused a fetch abort, if any
+ */
+struct iommu_fault_unrecoverable {
+       __u32   reason;
+#define IOMMU_FAULT_UNRECOV_PASID_VALID                (1 << 0)
+#define IOMMU_FAULT_UNRECOV_ADDR_VALID         (1 << 1)
+#define IOMMU_FAULT_UNRECOV_FETCH_ADDR_VALID   (1 << 2)
+       __u32   flags;
+       __u32   pasid;
+       __u32   perm;
+       __u64   addr;
+       __u64   fetch_addr;
+};
+
+/**
+ * struct iommu_fault_page_request - Page Request data
+ * @flags: encodes whether the corresponding fields are valid and whether this
+ *         is the last page in group (IOMMU_FAULT_PAGE_REQUEST_* values).
+ *         When IOMMU_FAULT_PAGE_RESPONSE_NEEDS_PASID is set, the page response
+ *         must have the same PASID value as the page request. When it is 
clear,
+ *         the page response should not have a PASID.
+ * @pasid: Process Address Space ID
+ * @grpid: Page Request Group Index
+ * @perm: requested page permissions (IOMMU_FAULT_PERM_* values)
+ * @addr: page address
+ * @private_data: device-specific private information
+ */
+struct iommu_fault_page_request {
+#define IOMMU_FAULT_PAGE_REQUEST_PASID_VALID   (1 << 0)
+#define IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE     (1 << 1)
+#define IOMMU_FAULT_PAGE_REQUEST_PRIV_DATA     (1 << 2)
+#define IOMMU_FAULT_PAGE_RESPONSE_NEEDS_PASID  (1 << 3)
+       __u32   flags;
+       __u32   pasid;
+       __u32   grpid;
+       __u32   perm;
+       __u64   addr;
+       __u64   private_data[2];
+};
+
+/**
+ * struct iommu_fault - Generic fault data
+ * @type: fault type from &enum iommu_fault_type
+ * @padding: reserved for future use (should be zero)
+ * @event: fault event, when @type is %IOMMU_FAULT_DMA_UNRECOV
+ * @prm: Page Request message, when @type is %IOMMU_FAULT_PAGE_REQ
+ * @padding2: sets the fault size to allow for future extensions
+ */
+struct iommu_fault {
+       __u32   type;
+       __u32   padding;
+       union {
+               struct iommu_fault_unrecoverable event;
+               struct iommu_fault_page_request prm;
+               __u8 padding2[56];
+       };
+};
+
+/**
+ * enum iommu_page_response_code - Return status of fault handlers
+ * @IOMMU_PAGE_RESP_SUCCESS: Fault has been handled and the page tables
+ *     populated, retry the access. This is "Success" in PCI PRI.
+ * @IOMMU_PAGE_RESP_FAILURE: General error. Drop all subsequent faults from
+ *     this device if possible. This is "Response Failure" in PCI PRI.
+ * @IOMMU_PAGE_RESP_INVALID: Could not handle this fault, don't retry the
+ *     access. This is "Invalid Request" in PCI PRI.
+ */
+enum iommu_page_response_code {
+       IOMMU_PAGE_RESP_SUCCESS = 0,
+       IOMMU_PAGE_RESP_INVALID,
+       IOMMU_PAGE_RESP_FAILURE,
+};
+
+/**
+ * struct iommu_page_response - Generic page response information
+ * @argsz: User filled size of this data
+ * @version: API version of this structure
+ * @flags: encodes whether the corresponding fields are valid
+ *         (IOMMU_FAULT_PAGE_RESPONSE_* values)
+ * @pasid: Process Address Space ID
+ * @grpid: Page Request Group Index
+ * @code: response code from &enum iommu_page_response_code
+ */
+struct iommu_page_response {
+       __u32   argsz;
+#define IOMMU_PAGE_RESP_VERSION_1      1
+       __u32   version;
+#define IOMMU_PAGE_RESP_PASID_VALID    (1 << 0)
+       __u32   flags;
+       __u32   pasid;
+       __u32   grpid;
+       __u32   code;
+};
+
+/* defines the granularity of the invalidation */
+enum iommu_inv_granularity {
+       IOMMU_INV_GRANU_DOMAIN, /* domain-selective invalidation */
+       IOMMU_INV_GRANU_PASID,  /* PASID-selective invalidation */
+       IOMMU_INV_GRANU_ADDR,   /* page-selective invalidation */
+       IOMMU_INV_GRANU_NR,     /* number of invalidation granularities */
+};
+
+/**
+ * struct iommu_inv_addr_info - Address Selective Invalidation Structure
+ *
+ * @flags: indicates the granularity of the address-selective invalidation
+ * - If the PASID bit is set, the @pasid field is populated and the 
invalidation
+ *   relates to cache entries tagged with this PASID and matching the address
+ *   range.
+ * - If ARCHID bit is set, @archid is populated and the invalidation relates
+ *   to cache entries tagged with this architecture specific ID and matching
+ *   the address range.
+ * - Both PASID and ARCHID can be set as they may tag different caches.
+ * - If neither PASID or ARCHID is set, global addr invalidation applies.
+ * - The LEAF flag indicates whether only the leaf PTE caching needs to be
+ *   invalidated and other paging structure caches can be preserved.
+ * @pasid: process address space ID
+ * @archid: architecture-specific ID
+ * @addr: first stage/level input address
+ * @granule_size: page/block size of the mapping in bytes
+ * @nb_granules: number of contiguous granules to be invalidated
+ */
+struct iommu_inv_addr_info {
+#define IOMMU_INV_ADDR_FLAGS_PASID     (1 << 0)
+#define IOMMU_INV_ADDR_FLAGS_ARCHID    (1 << 1)
+#define IOMMU_INV_ADDR_FLAGS_LEAF      (1 << 2)
+       __u32   flags;
+       __u32   archid;
+       __u64   pasid;
+       __u64   addr;
+       __u64   granule_size;
+       __u64   nb_granules;
+};
+
+/**
+ * struct iommu_inv_pasid_info - PASID Selective Invalidation Structure
+ *
+ * @flags: indicates the granularity of the PASID-selective invalidation
+ * - If the PASID bit is set, the @pasid field is populated and the 
invalidation
+ *   relates to cache entries tagged with this PASID and matching the address
+ *   range.
+ * - If the ARCHID bit is set, the @archid is populated and the invalidation
+ *   relates to cache entries tagged with this architecture specific ID and
+ *   matching the address range.
+ * - Both PASID and ARCHID can be set as they may tag different caches.
+ * - At least one of PASID or ARCHID must be set.
+ * @pasid: process address space ID
+ * @archid: architecture-specific ID
+ */
+struct iommu_inv_pasid_info {
+#define IOMMU_INV_PASID_FLAGS_PASID    (1 << 0)
+#define IOMMU_INV_PASID_FLAGS_ARCHID   (1 << 1)
+       __u32   flags;
+       __u32   archid;
+       __u64   pasid;
+};
+
+/**
+ * struct iommu_cache_invalidate_info - First level/stage invalidation
+ *     information
+ * @argsz: User filled size of this data
+ * @version: API version of this structure
+ * @cache: bitfield that allows to select which caches to invalidate
+ * @granularity: defines the lowest granularity used for the invalidation:
+ *     domain > PASID > addr
+ * @padding: reserved for future use (should be zero)
+ * @pasid_info: invalidation data when @granularity is %IOMMU_INV_GRANU_PASID
+ * @addr_info: invalidation data when @granularity is %IOMMU_INV_GRANU_ADDR
+ *
+ * Not all the combinations of cache/granularity are valid:
+ *
+ * +--------------+---------------+---------------+---------------+
+ * | type /       |   DEV_IOTLB   |     IOTLB     |      PASID    |
+ * | granularity  |               |               |      cache    |
+ * +==============+===============+===============+===============+
+ * | DOMAIN       |       N/A     |       Y       |       Y       |
+ * +--------------+---------------+---------------+---------------+
+ * | PASID        |       Y       |       Y       |       Y       |
+ * +--------------+---------------+---------------+---------------+
+ * | ADDR         |       Y       |       Y       |       N/A     |
+ * +--------------+---------------+---------------+---------------+
+ *
+ * Invalidations by %IOMMU_INV_GRANU_DOMAIN don't take any argument other than
+ * @version and @cache.
+ *
+ * If multiple cache types are invalidated simultaneously, they all
+ * must support the used granularity.
+ */
+struct iommu_cache_invalidate_info {
+       __u32   argsz;
+#define IOMMU_CACHE_INVALIDATE_INFO_VERSION_1 1
+       __u32   version;
+/* IOMMU paging structure cache */
+#define IOMMU_CACHE_INV_TYPE_IOTLB     (1 << 0) /* IOMMU IOTLB */
+#define IOMMU_CACHE_INV_TYPE_DEV_IOTLB (1 << 1) /* Device IOTLB */
+#define IOMMU_CACHE_INV_TYPE_PASID     (1 << 2) /* PASID cache */
+#define IOMMU_CACHE_INV_TYPE_NR                (3)
+       __u8    cache;
+       __u8    granularity;
+       __u8    padding[6];
+       union {
+               struct iommu_inv_pasid_info pasid_info;
+               struct iommu_inv_addr_info addr_info;
+       } granu;
+};
+
+/**
+ * struct iommu_gpasid_bind_data_vtd - Intel VT-d specific data on device and 
guest
+ * SVA binding.
+ *
+ * @flags:     VT-d PASID table entry attributes
+ * @pat:       Page attribute table data to compute effective memory type
+ * @emt:       Extended memory type
+ *
+ * Only guest vIOMMU selectable and effective options are passed down to
+ * the host IOMMU.
+ */
+struct iommu_gpasid_bind_data_vtd {
+#define IOMMU_SVA_VTD_GPASID_SRE       (1 << 0) /* supervisor request */
+#define IOMMU_SVA_VTD_GPASID_EAFE      (1 << 1) /* extended access enable */
+#define IOMMU_SVA_VTD_GPASID_PCD       (1 << 2) /* page-level cache disable */
+#define IOMMU_SVA_VTD_GPASID_PWT       (1 << 3) /* page-level write through */
+#define IOMMU_SVA_VTD_GPASID_EMTE      (1 << 4) /* extended mem type enable */
+#define IOMMU_SVA_VTD_GPASID_CD                (1 << 5) /* PASID-level cache 
disable */
+#define IOMMU_SVA_VTD_GPASID_LAST      (1 << 6)
+       __u64 flags;
+       __u32 pat;
+       __u32 emt;
+};
+
+#define IOMMU_SVA_VTD_GPASID_MTS_MASK  (IOMMU_SVA_VTD_GPASID_CD | \
+                                        IOMMU_SVA_VTD_GPASID_EMTE | \
+                                        IOMMU_SVA_VTD_GPASID_PCD |  \
+                                        IOMMU_SVA_VTD_GPASID_PWT)
+
+enum iommu_pasid_data_format {
+       IOMMU_PASID_FORMAT_INTEL_VTD = 1,
+       IOMMU_PASID_FORMAT_LAST,
+};
+
+/**
+ * struct iommu_gpasid_bind_data - Information about device and guest PASID 
binding
+ * @argsz:     User filled size of this data
+ * @version:   Version of this data structure
+ * @format:    PASID table entry format of enum iommu_pasid_data_format type
+ * @flags:     Additional information on guest bind request
+ * @gpgd:      Guest page directory base of the guest mm to bind
+ * @hpasid:    Process address space ID used for the guest mm in host IOMMU
+ * @gpasid:    Process address space ID used for the guest mm in guest IOMMU
+ * @addr_width:        Guest virtual address width
+ * @padding:   Reserved for future use (should be zero)
+ * @vtd:       Intel VT-d specific data
+ *
+ * Guest to host PASID mapping can be an identity or non-identity, where guest
+ * has its own PASID space. For non-identify mapping, guest to host PASID 
lookup
+ * is needed when VM programs guest PASID into an assigned device. VMM may
+ * trap such PASID programming then request host IOMMU driver to convert guest
+ * PASID to host PASID based on this bind data.
+ */
+struct iommu_gpasid_bind_data {
+       __u32 argsz;
+#define IOMMU_GPASID_BIND_VERSION_1    1
+       __u32 version;
+       __u32 format;
+       __u32 addr_width;
+#define IOMMU_SVA_GPASID_VAL   (1 << 0) /* guest PASID valid */
+       __u64 flags;
+       __u64 gpgd;
+       __u64 hpasid;
+       __u64 gpasid;
+       __u8  padding[8];
+       /* Vendor specific data */
+       union {
+               struct iommu_gpasid_bind_data_vtd vtd;
+       } vendor;
+};
+
+/*
+ * struct iommu_nesting_info_vtd - Intel VT-d specific nesting info.
+ *
+ * @flags:     VT-d specific flags. Currently reserved for future
+ *             extension. must be set to 0.
+ * @cap_reg:   Describe basic capabilities as defined in VT-d capability
+ *             register.
+ * @ecap_reg:  Describe the extended capabilities as defined in VT-d
+ *             extended capability register.
+ */
+struct iommu_nesting_info_vtd {
+       __u32   flags;
+       __u64   cap_reg;
+       __u64   ecap_reg;
+};
+
+/*
+ * struct iommu_nesting_info - Information for nesting-capable IOMMU.
+ *                            userspace should check it before using
+ *                            nesting capability.
+ *
+ * @argsz:     size of the whole structure.
+ * @flags:     currently reserved for future extension. must set to 0.
+ * @format:    PASID table entry format, the same definition as struct
+ *             iommu_gpasid_bind_data @format.
+ * @features:  supported nesting features.
+ * @addr_width:        The output addr width of first level/stage translation
+ * @pasid_bits:        Maximum supported PASID bits, 0 represents no PASID
+ *             support.
+ * @vendor:    vendor specific data, structure type can be deduced from
+ *             @format field.
+ *
+ * +===============+======================================================+
+ * | feature       |  Notes                                               |
+ * +===============+======================================================+
+ * | SYSWIDE_PASID |  IOMMU vendor driver sets it to mandate userspace    |
+ * |               |  to allocate PASID from kernel. All PASID allocation |
+ * |               |  free must be mediated through the IOMMU UAPI.       |
+ * +---------------+------------------------------------------------------+
+ * | BIND_PGTBL    |  IOMMU vendor driver sets it to mandate userspace to |
+ * |               |  bind the first level/stage page table to associated |
+ * |               |  PASID (either the one specified in bind request or  |
+ * |               |  the default PASID of iommu domain), through IOMMU   |
+ * |               |  UAPI.                                               |
+ * +---------------+------------------------------------------------------+
+ * | CACHE_INVLD   |  IOMMU vendor driver sets it to mandate userspace to |
+ * |               |  explicitly invalidate the IOMMU cache through IOMMU |
+ * |               |  UAPI according to vendor-specific requirement when  |
+ * |               |  changing the 1st level/stage page table.            |
+ * +---------------+------------------------------------------------------+
+ *
+ * data struct types defined for @format:
+ * +================================+=====================================+
+ * | @format                        | data struct                         |
+ * +================================+=====================================+
+ * | IOMMU_PASID_FORMAT_INTEL_VTD   | struct iommu_nesting_info_vtd       |
+ * +--------------------------------+-------------------------------------+
+ *
+ */
+struct iommu_nesting_info {
+       __u32   argsz;
+       __u32   flags;
+       __u32   format;
+#define IOMMU_NESTING_FEAT_SYSWIDE_PASID       (1 << 0)
+#define IOMMU_NESTING_FEAT_BIND_PGTBL          (1 << 1)
+#define IOMMU_NESTING_FEAT_CACHE_INVLD         (1 << 2)
+       __u32   features;
+       __u16   addr_width;
+       __u16   pasid_bits;
+       __u8    padding[12];
+       /* Vendor specific data */
+       union {
+               struct iommu_nesting_info_vtd vtd;
+       } vendor;
+};
+
+#endif /* _IOMMU_H */
diff --git a/linux-headers/linux/vfio.h b/linux-headers/linux/vfio.h
index f09df26..97ff88c 100644
--- a/linux-headers/linux/vfio.h
+++ b/linux-headers/linux/vfio.h
@@ -14,6 +14,7 @@
 
 #include <linux/types.h>
 #include <linux/ioctl.h>
+#include <linux/iommu.h>
 
 #define VFIO_API_VERSION       0
 
@@ -1030,7 +1031,7 @@ struct vfio_iommu_type1_info_cap_iova_range {
  * size in bytes that can be used by user applications when getting the dirty
  * bitmap.
  */
-#define VFIO_IOMMU_TYPE1_INFO_CAP_MIGRATION  1
+#define VFIO_IOMMU_TYPE1_INFO_CAP_MIGRATION  2
 
 struct vfio_iommu_type1_info_cap_migration {
        struct  vfio_info_cap_header header;
@@ -1039,6 +1040,24 @@ struct vfio_iommu_type1_info_cap_migration {
        __u64   max_dirty_bitmap_size;          /* in bytes */
 };
 
+/*
+ * The nesting capability allows to report the related capability
+ * and info for nesting iommu type.
+ *
+ * The structures below define version 1 of this capability.
+ *
+ * Nested capabilities should be checked by the userspace after
+ * setting VFIO_TYPE1_NESTING_IOMMU.
+ *
+ * @info: the nesting info provided by IOMMU driver.
+ */
+#define VFIO_IOMMU_TYPE1_INFO_CAP_NESTING  3
+
+struct vfio_iommu_type1_info_cap_nesting {
+       struct  vfio_info_cap_header header;
+       struct  iommu_nesting_info info;
+};
+
 #define VFIO_IOMMU_GET_INFO _IO(VFIO_TYPE, VFIO_BASE + 12)
 
 /**
@@ -1153,6 +1172,88 @@ struct vfio_iommu_type1_dirty_bitmap_get {
 
 #define VFIO_IOMMU_DIRTY_PAGES             _IO(VFIO_TYPE, VFIO_BASE + 17)
 
+/**
+ * VFIO_IOMMU_PASID_REQUEST - _IOWR(VFIO_TYPE, VFIO_BASE + 18,
+ *                             struct vfio_iommu_type1_pasid_request)
+ *
+ * PASID (Processor Address Space ID) is a PCIe concept for tagging
+ * address spaces in DMA requests. When system-wide PASID allocation
+ * is required by the underlying iommu driver (e.g. Intel VT-d), this
+ * provides an interface for userspace to request pasid alloc/free
+ * for its assigned devices. Userspace should check the availability
+ * of this API by checking VFIO_IOMMU_TYPE1_INFO_CAP_NESTING through
+ * VFIO_IOMMU_GET_INFO.
+ *
+ * @flags=VFIO_IOMMU_FLAG_ALLOC_PASID, allocate a single PASID within @range.
+ * @flags=VFIO_IOMMU_FLAG_FREE_PASID, free the PASIDs within @range.
+ * @range is [min, max], which means both @min and @max are inclusive.
+ * ALLOC_PASID and FREE_PASID are mutually exclusive.
+ *
+ * Current interface supports at most 31 bits PASID bits as returning
+ * PASID allocation result via singed int. PCIe spec defines 20 bits
+ * for PASID width, so 31 bits is enough. As a result user space should
+ * provide min, max no more than 31 bits.
+ * returns: allocated PASID value on success, -errno on failure for
+ *         ALLOC_PASID;
+ *         0 for FREE_PASID operation;
+ */
+struct vfio_iommu_type1_pasid_request {
+       __u32   argsz;
+#define VFIO_IOMMU_FLAG_ALLOC_PASID    (1 << 0)
+#define VFIO_IOMMU_FLAG_FREE_PASID     (1 << 1)
+       __u32   flags;
+       struct {
+               __u32   min;
+               __u32   max;
+       } range;
+};
+
+#define VFIO_PASID_REQUEST_MASK        (VFIO_IOMMU_FLAG_ALLOC_PASID | \
+                                        VFIO_IOMMU_FLAG_FREE_PASID)
+
+#define VFIO_IOMMU_PASID_BITS          31
+
+#define VFIO_IOMMU_PASID_REQUEST       _IO(VFIO_TYPE, VFIO_BASE + 18)
+
+/**
+ * VFIO_IOMMU_NESTING_OP - _IOW(VFIO_TYPE, VFIO_BASE + 19,
+ *                             struct vfio_iommu_type1_nesting_op)
+ *
+ * This interface allows userspace to utilize the nesting IOMMU
+ * capabilities as reported in VFIO_IOMMU_TYPE1_INFO_CAP_NESTING
+ * cap through VFIO_IOMMU_GET_INFO. For platforms which require
+ * system wide PASID, PASID will be allocated by VFIO_IOMMU_PASID
+ * _REQUEST.
+ *
+ * @data[] types defined for each op:
+ * +=================+===============================================+
+ * | NESTING OP      |      @data[]                                  |
+ * +=================+===============================================+
+ * | BIND_PGTBL      |      struct iommu_gpasid_bind_data            |
+ * +-----------------+-----------------------------------------------+
+ * | UNBIND_PGTBL    |      struct iommu_gpasid_bind_data            |
+ * +-----------------+-----------------------------------------------+
+ * | CACHE_INVLD     |      struct iommu_cache_invalidate_info       |
+ * +-----------------+-----------------------------------------------+
+ *
+ * returns: 0 on success, -errno on failure.
+ */
+struct vfio_iommu_type1_nesting_op {
+       __u32   argsz;
+       __u32   flags;
+#define VFIO_NESTING_OP_MASK   (0xffff) /* lower 16-bits for op */
+       __u8    data[];
+};
+
+enum {
+       VFIO_IOMMU_NESTING_OP_BIND_PGTBL,
+       VFIO_IOMMU_NESTING_OP_UNBIND_PGTBL,
+       VFIO_IOMMU_NESTING_OP_CACHE_INVLD,
+       VFIO_IOMMU_NESTING_OP_NUM,
+};
+
+#define VFIO_IOMMU_NESTING_OP          _IO(VFIO_TYPE, VFIO_BASE + 19)
+
 /* -------- Additional API for SPAPR TCE (Server POWERPC) IOMMU -------- */
 
 /*
-- 
2.7.4