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0f9f5a9588
This patch introduces new structures of grant table V2, grant table V2 is an extension from V1. Grant table is shared between guest and Xen, and Xen is responsible to do corresponding work for grant operations, such as: figure out guest's grant table version, perform different actions based on different grant table version, etc. Although full-page structure of V2 is different from V1, it play the same role as V1. Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: Annie Li <annie.li@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
91 lines
3.0 KiB
C
91 lines
3.0 KiB
C
/******************************************************************************
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* grant_table.c
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* x86 specific part
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*
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* Granting foreign access to our memory reservation.
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*
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* Copyright (c) 2005-2006, Christopher Clark
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* Copyright (c) 2004-2005, K A Fraser
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* Copyright (c) 2008 Isaku Yamahata <yamahata at valinux co jp>
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* VA Linux Systems Japan. Split out x86 specific part.
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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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#include <linux/sched.h>
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#include <linux/mm.h>
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#include <linux/vmalloc.h>
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#include <xen/interface/xen.h>
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#include <xen/page.h>
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#include <xen/grant_table.h>
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#include <asm/pgtable.h>
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static int map_pte_fn(pte_t *pte, struct page *pmd_page,
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unsigned long addr, void *data)
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{
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unsigned long **frames = (unsigned long **)data;
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set_pte_at(&init_mm, addr, pte, mfn_pte((*frames)[0], PAGE_KERNEL));
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(*frames)++;
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return 0;
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}
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static int unmap_pte_fn(pte_t *pte, struct page *pmd_page,
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unsigned long addr, void *data)
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{
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set_pte_at(&init_mm, addr, pte, __pte(0));
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return 0;
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}
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int arch_gnttab_map_shared(unsigned long *frames, unsigned long nr_gframes,
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unsigned long max_nr_gframes,
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void **__shared)
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{
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int rc;
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void *shared = *__shared;
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if (shared == NULL) {
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struct vm_struct *area =
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alloc_vm_area(PAGE_SIZE * max_nr_gframes);
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BUG_ON(area == NULL);
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shared = area->addr;
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*__shared = shared;
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}
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rc = apply_to_page_range(&init_mm, (unsigned long)shared,
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PAGE_SIZE * nr_gframes,
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map_pte_fn, &frames);
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return rc;
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}
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void arch_gnttab_unmap_shared(void *shared, unsigned long nr_gframes)
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{
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apply_to_page_range(&init_mm, (unsigned long)shared,
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PAGE_SIZE * nr_gframes, unmap_pte_fn, NULL);
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}
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