xref: /linux/drivers/xen/xlate_mmu.c (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
1 /*
2  * MMU operations common to all auto-translated physmap guests.
3  *
4  * Copyright (C) 2015 Citrix Systems R&D Ltd.
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License version 2
8  * as published by the Free Software Foundation; or, when distributed
9  * separately from the Linux kernel or incorporated into other
10  * software packages, subject to the following license:
11  *
12  * Permission is hereby granted, free of charge, to any person obtaining a copy
13  * of this source file (the "Software"), to deal in the Software without
14  * restriction, including without limitation the rights to use, copy, modify,
15  * merge, publish, distribute, sublicense, and/or sell copies of the Software,
16  * and to permit persons to whom the Software is furnished to do so, subject to
17  * the following conditions:
18  *
19  * The above copyright notice and this permission notice shall be included in
20  * all copies or substantial portions of the Software.
21  *
22  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
23  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
24  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
25  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
26  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
27  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
28  * IN THE SOFTWARE.
29  */
30 #include <linux/kernel.h>
31 #include <linux/mm.h>
32 
33 #include <asm/xen/hypercall.h>
34 #include <asm/xen/hypervisor.h>
35 
36 #include <xen/xen.h>
37 #include <xen/page.h>
38 #include <xen/interface/xen.h>
39 #include <xen/interface/memory.h>
40 
41 /* map fgfn of domid to lpfn in the current domain */
42 static int map_foreign_page(unsigned long lpfn, unsigned long fgfn,
43 			    unsigned int domid)
44 {
45 	int rc;
46 	struct xen_add_to_physmap_range xatp = {
47 		.domid = DOMID_SELF,
48 		.foreign_domid = domid,
49 		.size = 1,
50 		.space = XENMAPSPACE_gmfn_foreign,
51 	};
52 	xen_ulong_t idx = fgfn;
53 	xen_pfn_t gpfn = lpfn;
54 	int err = 0;
55 
56 	set_xen_guest_handle(xatp.idxs, &idx);
57 	set_xen_guest_handle(xatp.gpfns, &gpfn);
58 	set_xen_guest_handle(xatp.errs, &err);
59 
60 	rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap_range, &xatp);
61 	return rc < 0 ? rc : err;
62 }
63 
64 struct remap_data {
65 	xen_pfn_t *fgfn; /* foreign domain's gfn */
66 	pgprot_t prot;
67 	domid_t  domid;
68 	struct vm_area_struct *vma;
69 	int index;
70 	struct page **pages;
71 	struct xen_remap_gfn_info *info;
72 	int *err_ptr;
73 	int mapped;
74 };
75 
76 static int remap_pte_fn(pte_t *ptep, pgtable_t token, unsigned long addr,
77 			void *data)
78 {
79 	struct remap_data *info = data;
80 	struct page *page = info->pages[info->index++];
81 	unsigned long pfn = page_to_pfn(page);
82 	pte_t pte = pte_mkspecial(pfn_pte(pfn, info->prot));
83 	int rc;
84 
85 	rc = map_foreign_page(pfn, *info->fgfn, info->domid);
86 	*info->err_ptr++ = rc;
87 	if (!rc) {
88 		set_pte_at(info->vma->vm_mm, addr, ptep, pte);
89 		info->mapped++;
90 	}
91 	info->fgfn++;
92 
93 	return 0;
94 }
95 
96 int xen_xlate_remap_gfn_array(struct vm_area_struct *vma,
97 			      unsigned long addr,
98 			      xen_pfn_t *gfn, int nr,
99 			      int *err_ptr, pgprot_t prot,
100 			      unsigned domid,
101 			      struct page **pages)
102 {
103 	int err;
104 	struct remap_data data;
105 	unsigned long range = nr << PAGE_SHIFT;
106 
107 	/* Kept here for the purpose of making sure code doesn't break
108 	   x86 PVOPS */
109 	BUG_ON(!((vma->vm_flags & (VM_PFNMAP | VM_IO)) == (VM_PFNMAP | VM_IO)));
110 
111 	data.fgfn = gfn;
112 	data.prot  = prot;
113 	data.domid = domid;
114 	data.vma   = vma;
115 	data.pages = pages;
116 	data.index = 0;
117 	data.err_ptr = err_ptr;
118 	data.mapped = 0;
119 
120 	err = apply_to_page_range(vma->vm_mm, addr, range,
121 				  remap_pte_fn, &data);
122 	return err < 0 ? err : data.mapped;
123 }
124 EXPORT_SYMBOL_GPL(xen_xlate_remap_gfn_array);
125 
126 int xen_xlate_unmap_gfn_range(struct vm_area_struct *vma,
127 			      int nr, struct page **pages)
128 {
129 	int i;
130 
131 	for (i = 0; i < nr; i++) {
132 		struct xen_remove_from_physmap xrp;
133 		unsigned long pfn;
134 
135 		pfn = page_to_pfn(pages[i]);
136 
137 		xrp.domid = DOMID_SELF;
138 		xrp.gpfn = pfn;
139 		(void)HYPERVISOR_memory_op(XENMEM_remove_from_physmap, &xrp);
140 	}
141 	return 0;
142 }
143 EXPORT_SYMBOL_GPL(xen_xlate_unmap_gfn_range);
144