/* SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR MIT) */ /****************************************************************************** * gntdev.h * * Interface to /dev/xen/gntdev. * * Copyright (c) 2007, D G Murray * Copyright (c) 2018, Oleksandr Andrushchenko, EPAM Systems Inc. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License version 2 * as published by the Free Software Foundation; or, when distributed * separately from the Linux kernel or incorporated into other * software packages, subject to the following license: * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this source file (the "Software"), to deal in the Software without * restriction, including without limitation the rights to use, copy, modify, * merge, publish, distribute, sublicense, and/or sell copies of the Software, * and to permit persons to whom the Software is furnished to do so, subject to * the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS * IN THE SOFTWARE. */ #ifndef __LINUX_PUBLIC_GNTDEV_H__ #define __LINUX_PUBLIC_GNTDEV_H__ #include <linux/types.h> struct ioctl_gntdev_grant_ref { /* The domain ID of the grant to be mapped. */ __u32 domid; /* The grant reference of the grant to be mapped. */ __u32 ref; }; /* * Inserts the grant references into the mapping table of an instance * of gntdev. N.B. This does not perform the mapping, which is deferred * until mmap() is called with @index as the offset. @index should be * considered opaque to userspace, with one exception: if no grant * references have ever been inserted into the mapping table of this * instance, @index will be set to 0. This is necessary to use gntdev * with userspace APIs that expect a file descriptor that can be * mmap()'d at offset 0, such as Wayland. If @count is set to 0, this * ioctl will fail. */ #define IOCTL_GNTDEV_MAP_GRANT_REF \ _IOC(_IOC_NONE, 'G', 0, sizeof(struct ioctl_gntdev_map_grant_ref)) struct ioctl_gntdev_map_grant_ref { /* IN parameters */ /* The number of grants to be mapped. */ __u32 count; __u32 pad; /* OUT parameters */ /* The offset to be used on a subsequent call to mmap(). */ __u64 index; /* Variable IN parameter. */ /* Array of grant references, of size @count. */ struct ioctl_gntdev_grant_ref refs[1]; }; /* * Removes the grant references from the mapping table of an instance of * gntdev. N.B. munmap() must be called on the relevant virtual address(es) * before this ioctl is called, or an error will result. */ #define IOCTL_GNTDEV_UNMAP_GRANT_REF \ _IOC(_IOC_NONE, 'G', 1, sizeof(struct ioctl_gntdev_unmap_grant_ref)) struct ioctl_gntdev_unmap_grant_ref { /* IN parameters */ /* The offset was returned by the corresponding map operation. */ __u64 index; /* The number of pages to be unmapped. */ __u32 count; __u32 pad; }; /* * Returns the offset in the driver's address space that corresponds * to @vaddr. This can be used to perform a munmap(), followed by an * UNMAP_GRANT_REF ioctl, where no state about the offset is retained by * the caller. The number of pages that were allocated at the same time as * @vaddr is returned in @count. * * N.B. Where more than one page has been mapped into a contiguous range, the * supplied @vaddr must correspond to the start of the range; otherwise * an error will result. It is only possible to munmap() the entire * contiguously-allocated range at once, and not any subrange thereof. */ #define IOCTL_GNTDEV_GET_OFFSET_FOR_VADDR \ _IOC(_IOC_NONE, 'G', 2, sizeof(struct ioctl_gntdev_get_offset_for_vaddr)) struct ioctl_gntdev_get_offset_for_vaddr { /* IN parameters */ /* The virtual address of the first mapped page in a range. */ __u64 vaddr; /* OUT parameters */ /* The offset that was used in the initial mmap() operation. */ __u64 offset; /* The number of pages mapped in the VM area that begins at @vaddr. */ __u32 count; __u32 pad; }; /* * Sets the maximum number of grants that may mapped at once by this gntdev * instance. * * N.B. This must be called before any other ioctl is performed on the device. */ #define IOCTL_GNTDEV_SET_MAX_GRANTS \ _IOC(_IOC_NONE, 'G', 3, sizeof(struct ioctl_gntdev_set_max_grants)) struct ioctl_gntdev_set_max_grants { /* IN parameter */ /* The maximum number of grants that may be mapped at once. */ __u32 count; }; /* * Sets up an unmap notification within the page, so that the other side can do * cleanup if this side crashes. Required to implement cross-domain robust * mutexes or close notification on communication channels. * * Each mapped page only supports one notification; multiple calls referring to * the same page overwrite the previous notification. You must clear the * notification prior to the IOCTL_GNTALLOC_DEALLOC_GREF if you do not want it * to occur. */ #define IOCTL_GNTDEV_SET_UNMAP_NOTIFY \ _IOC(_IOC_NONE, 'G', 7, sizeof(struct ioctl_gntdev_unmap_notify)) struct ioctl_gntdev_unmap_notify { /* IN parameters */ /* Offset in the file descriptor for a byte within the page (same as * used in mmap). If using UNMAP_NOTIFY_CLEAR_BYTE, this is the byte to * be cleared. Otherwise, it can be any byte in the page whose * notification we are adjusting. */ __u64 index; /* Action(s) to take on unmap */ __u32 action; /* Event channel to notify */ __u32 event_channel_port; }; struct gntdev_grant_copy_segment { union { void __user *virt; struct { grant_ref_t ref; __u16 offset; domid_t domid; } foreign; } source, dest; __u16 len; __u16 flags; /* GNTCOPY_* */ __s16 status; /* GNTST_* */ }; /* * Copy between grant references and local buffers. * * The copy is split into @count @segments, each of which can copy * to/from one grant reference. * * Each segment is similar to struct gnttab_copy in the hypervisor ABI * except the local buffer is specified using a virtual address * (instead of a GFN and offset). * * The local buffer may cross a Xen page boundary -- the driver will * split segments into multiple ops if required. * * Returns 0 if all segments have been processed and @status in each * segment is valid. Note that one or more segments may have failed * (status != GNTST_okay). * * If the driver had to split a segment into two or more ops, @status * includes the status of the first failed op for that segment (or * GNTST_okay if all ops were successful). * * If -1 is returned, the status of all segments is undefined. * * EINVAL: A segment has local buffers for both source and * destination. * EINVAL: A segment crosses the boundary of a foreign page. * EFAULT: A segment's local buffer is not accessible. */ #define IOCTL_GNTDEV_GRANT_COPY \ _IOC(_IOC_NONE, 'G', 8, sizeof(struct ioctl_gntdev_grant_copy)) struct ioctl_gntdev_grant_copy { unsigned int count; struct gntdev_grant_copy_segment __user *segments; }; /* Clear (set to zero) the byte specified by index */ #define UNMAP_NOTIFY_CLEAR_BYTE 0x1 /* Send an interrupt on the indicated event channel */ #define UNMAP_NOTIFY_SEND_EVENT 0x2 /* * Flags to be used while requesting memory mapping's backing storage * to be allocated with DMA API. */ /* * The buffer is backed with memory allocated with dma_alloc_wc. */ #define GNTDEV_DMA_FLAG_WC (1 << 0) /* * The buffer is backed with memory allocated with dma_alloc_coherent. */ #define GNTDEV_DMA_FLAG_COHERENT (1 << 1) /* * Create a dma-buf [1] from grant references @refs of count @count provided * by the foreign domain @domid with flags @flags. * * By default dma-buf is backed by system memory pages, but by providing * one of the GNTDEV_DMA_FLAG_XXX flags it can also be created as * a DMA write-combine or coherent buffer, e.g. allocated with dma_alloc_wc/ * dma_alloc_coherent. * * Returns 0 if dma-buf was successfully created and the corresponding * dma-buf's file descriptor is returned in @fd. * * [1] Documentation/driver-api/dma-buf.rst */ #define IOCTL_GNTDEV_DMABUF_EXP_FROM_REFS \ _IOC(_IOC_NONE, 'G', 9, \ sizeof(struct ioctl_gntdev_dmabuf_exp_from_refs)) struct ioctl_gntdev_dmabuf_exp_from_refs { /* IN parameters. */ /* Specific options for this dma-buf: see GNTDEV_DMA_FLAG_XXX. */ __u32 flags; /* Number of grant references in @refs array. */ __u32 count; /* OUT parameters. */ /* File descriptor of the dma-buf. */ __u32 fd; /* The domain ID of the grant references to be mapped. */ __u32 domid; /* Variable IN parameter. */ /* Array of grant references of size @count. */ __u32 refs[1]; }; /* * This will block until the dma-buf with the file descriptor @fd is * released. This is only valid for buffers created with * IOCTL_GNTDEV_DMABUF_EXP_FROM_REFS. * * If within @wait_to_ms milliseconds the buffer is not released * then -ETIMEDOUT error is returned. * If the buffer with the file descriptor @fd does not exist or has already * been released, then -ENOENT is returned. For valid file descriptors * this must not be treated as error. */ #define IOCTL_GNTDEV_DMABUF_EXP_WAIT_RELEASED \ _IOC(_IOC_NONE, 'G', 10, \ sizeof(struct ioctl_gntdev_dmabuf_exp_wait_released)) struct ioctl_gntdev_dmabuf_exp_wait_released { /* IN parameters */ __u32 fd; __u32 wait_to_ms; }; /* * Import a dma-buf with file descriptor @fd and export granted references * to the pages of that dma-buf into array @refs of size @count. */ #define IOCTL_GNTDEV_DMABUF_IMP_TO_REFS \ _IOC(_IOC_NONE, 'G', 11, \ sizeof(struct ioctl_gntdev_dmabuf_imp_to_refs)) struct ioctl_gntdev_dmabuf_imp_to_refs { /* IN parameters. */ /* File descriptor of the dma-buf. */ __u32 fd; /* Number of grant references in @refs array. */ __u32 count; /* The domain ID for which references to be granted. */ __u32 domid; /* Reserved - must be zero. */ __u32 reserved; /* OUT parameters. */ /* Array of grant references of size @count. */ __u32 refs[1]; }; /* * This will close all references to the imported buffer with file descriptor * @fd, so it can be released by the owner. This is only valid for buffers * created with IOCTL_GNTDEV_DMABUF_IMP_TO_REFS. */ #define IOCTL_GNTDEV_DMABUF_IMP_RELEASE \ _IOC(_IOC_NONE, 'G', 12, \ sizeof(struct ioctl_gntdev_dmabuf_imp_release)) struct ioctl_gntdev_dmabuf_imp_release { /* IN parameters */ __u32 fd; __u32 reserved; }; #endif /* __LINUX_PUBLIC_GNTDEV_H__ */