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The gntdev driver allows usermode to map granted pages from other domains. This is typically used to implement a Xen backend driver in user mode. Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> Signed-off-by: Stefano Stabellini <Stefano.Stabellini@eu.citrix.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
120 lines
4.5 KiB
C
120 lines
4.5 KiB
C
/******************************************************************************
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* gntdev.h
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*
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* Interface to /dev/xen/gntdev.
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*
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* Copyright (c) 2007, D G Murray
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License version 2
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* as published by the Free Software Foundation; or, when distributed
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* separately from the Linux kernel or incorporated into other
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* software packages, subject to the following license:
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this source file (the "Software"), to deal in the Software without
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* restriction, including without limitation the rights to use, copy, modify,
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* merge, publish, distribute, sublicense, and/or sell copies of the Software,
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* and to permit persons to whom the Software is furnished to do so, subject to
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* the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
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* IN THE SOFTWARE.
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*/
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#ifndef __LINUX_PUBLIC_GNTDEV_H__
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#define __LINUX_PUBLIC_GNTDEV_H__
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struct ioctl_gntdev_grant_ref {
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/* The domain ID of the grant to be mapped. */
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uint32_t domid;
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/* The grant reference of the grant to be mapped. */
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uint32_t ref;
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};
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/*
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* Inserts the grant references into the mapping table of an instance
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* of gntdev. N.B. This does not perform the mapping, which is deferred
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* until mmap() is called with @index as the offset.
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*/
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#define IOCTL_GNTDEV_MAP_GRANT_REF \
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_IOC(_IOC_NONE, 'G', 0, sizeof(struct ioctl_gntdev_map_grant_ref))
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struct ioctl_gntdev_map_grant_ref {
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/* IN parameters */
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/* The number of grants to be mapped. */
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uint32_t count;
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uint32_t pad;
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/* OUT parameters */
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/* The offset to be used on a subsequent call to mmap(). */
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uint64_t index;
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/* Variable IN parameter. */
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/* Array of grant references, of size @count. */
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struct ioctl_gntdev_grant_ref refs[1];
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};
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/*
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* Removes the grant references from the mapping table of an instance of
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* of gntdev. N.B. munmap() must be called on the relevant virtual address(es)
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* before this ioctl is called, or an error will result.
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*/
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#define IOCTL_GNTDEV_UNMAP_GRANT_REF \
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_IOC(_IOC_NONE, 'G', 1, sizeof(struct ioctl_gntdev_unmap_grant_ref))
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struct ioctl_gntdev_unmap_grant_ref {
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/* IN parameters */
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/* The offset was returned by the corresponding map operation. */
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uint64_t index;
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/* The number of pages to be unmapped. */
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uint32_t count;
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uint32_t pad;
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};
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/*
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* Returns the offset in the driver's address space that corresponds
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* to @vaddr. This can be used to perform a munmap(), followed by an
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* UNMAP_GRANT_REF ioctl, where no state about the offset is retained by
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* the caller. The number of pages that were allocated at the same time as
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* @vaddr is returned in @count.
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*
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* N.B. Where more than one page has been mapped into a contiguous range, the
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* supplied @vaddr must correspond to the start of the range; otherwise
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* an error will result. It is only possible to munmap() the entire
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* contiguously-allocated range at once, and not any subrange thereof.
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*/
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#define IOCTL_GNTDEV_GET_OFFSET_FOR_VADDR \
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_IOC(_IOC_NONE, 'G', 2, sizeof(struct ioctl_gntdev_get_offset_for_vaddr))
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struct ioctl_gntdev_get_offset_for_vaddr {
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/* IN parameters */
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/* The virtual address of the first mapped page in a range. */
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uint64_t vaddr;
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/* OUT parameters */
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/* The offset that was used in the initial mmap() operation. */
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uint64_t offset;
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/* The number of pages mapped in the VM area that begins at @vaddr. */
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uint32_t count;
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uint32_t pad;
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};
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/*
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* Sets the maximum number of grants that may mapped at once by this gntdev
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* instance.
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*
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* N.B. This must be called before any other ioctl is performed on the device.
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*/
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#define IOCTL_GNTDEV_SET_MAX_GRANTS \
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_IOC(_IOC_NONE, 'G', 3, sizeof(struct ioctl_gntdev_set_max_grants))
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struct ioctl_gntdev_set_max_grants {
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/* IN parameter */
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/* The maximum number of grants that may be mapped at once. */
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uint32_t count;
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};
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#endif /* __LINUX_PUBLIC_GNTDEV_H__ */
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