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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#include <linux/slab.h>
33#include <linux/vmalloc.h>
34
35#include <asm/xen/hypercall.h>
36#include <asm/xen/hypervisor.h>
37
38#include <xen/xen.h>
39#include <xen/xen-ops.h>
40#include <xen/page.h>
41#include <xen/interface/xen.h>
42#include <xen/interface/memory.h>
43#include <xen/balloon.h>
44
45typedef void (*xen_gfn_fn_t)(unsigned long gfn, void *data);
46
47/* Break down the pages in 4KB chunk and call fn for each gfn */
48static void xen_for_each_gfn(struct page **pages, unsigned nr_gfn,
49 xen_gfn_fn_t fn, void *data)
50{
51 unsigned long xen_pfn = 0;
52 struct page *page;
53 int i;
54
55 for (i = 0; i < nr_gfn; i++) {
56 if ((i % XEN_PFN_PER_PAGE) == 0) {
57 page = pages[i / XEN_PFN_PER_PAGE];
58 xen_pfn = page_to_xen_pfn(page);
59 }
60 fn(pfn_to_gfn(xen_pfn++), data);
61 }
62}
63
64struct remap_data {
65 xen_pfn_t *fgfn; /* foreign domain's gfn */
66 int nr_fgfn; /* Number of foreign gfn left to map */
67 pgprot_t prot;
68 domid_t domid;
69 struct vm_area_struct *vma;
70 int index;
71 struct page **pages;
72 struct xen_remap_gfn_info *info;
73 int *err_ptr;
74 int mapped;
75
76 /* Hypercall parameters */
77 int h_errs[XEN_PFN_PER_PAGE];
78 xen_ulong_t h_idxs[XEN_PFN_PER_PAGE];
79 xen_pfn_t h_gpfns[XEN_PFN_PER_PAGE];
80
81 int h_iter; /* Iterator */
82};
83
84static void setup_hparams(unsigned long gfn, void *data)
85{
86 struct remap_data *info = data;
87
88 info->h_idxs[info->h_iter] = *info->fgfn;
89 info->h_gpfns[info->h_iter] = gfn;
90 info->h_errs[info->h_iter] = 0;
91
92 info->h_iter++;
93 info->fgfn++;
94}
95
96static int remap_pte_fn(pte_t *ptep, unsigned long addr, void *data)
97{
98 struct remap_data *info = data;
99 struct page *page = info->pages[info->index++];
100 pte_t pte = pte_mkspecial(pfn_pte(page_to_pfn(page), info->prot));
101 int rc, nr_gfn;
102 uint32_t i;
103 struct xen_add_to_physmap_range xatp = {
104 .domid = DOMID_SELF,
105 .foreign_domid = info->domid,
106 .space = XENMAPSPACE_gmfn_foreign,
107 };
108
109 nr_gfn = min_t(typeof(info->nr_fgfn), XEN_PFN_PER_PAGE, info->nr_fgfn);
110 info->nr_fgfn -= nr_gfn;
111
112 info->h_iter = 0;
113 xen_for_each_gfn(&page, nr_gfn, setup_hparams, info);
114 BUG_ON(info->h_iter != nr_gfn);
115
116 set_xen_guest_handle(xatp.idxs, info->h_idxs);
117 set_xen_guest_handle(xatp.gpfns, info->h_gpfns);
118 set_xen_guest_handle(xatp.errs, info->h_errs);
119 xatp.size = nr_gfn;
120
121 rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap_range, &xatp);
122
123 /* info->err_ptr expect to have one error status per Xen PFN */
124 for (i = 0; i < nr_gfn; i++) {
125 int err = (rc < 0) ? rc : info->h_errs[i];
126
127 *(info->err_ptr++) = err;
128 if (!err)
129 info->mapped++;
130 }
131
132 /*
133 * Note: The hypercall will return 0 in most of the case if even if
134 * all the fgmfn are not mapped. We still have to update the pte
135 * as the userspace may decide to continue.
136 */
137 if (!rc)
138 set_pte_at(info->vma->vm_mm, addr, ptep, pte);
139
140 return 0;
141}
142
143int xen_xlate_remap_gfn_array(struct vm_area_struct *vma,
144 unsigned long addr,
145 xen_pfn_t *gfn, int nr,
146 int *err_ptr, pgprot_t prot,
147 unsigned domid,
148 struct page **pages)
149{
150 int err;
151 struct remap_data data;
152 unsigned long range = DIV_ROUND_UP(nr, XEN_PFN_PER_PAGE) << PAGE_SHIFT;
153
154 /* Kept here for the purpose of making sure code doesn't break
155 x86 PVOPS */
156 BUG_ON(!((vma->vm_flags & (VM_PFNMAP | VM_IO)) == (VM_PFNMAP | VM_IO)));
157
158 data.fgfn = gfn;
159 data.nr_fgfn = nr;
160 data.prot = prot;
161 data.domid = domid;
162 data.vma = vma;
163 data.pages = pages;
164 data.index = 0;
165 data.err_ptr = err_ptr;
166 data.mapped = 0;
167
168 err = apply_to_page_range(vma->vm_mm, addr, range,
169 remap_pte_fn, &data);
170 return err < 0 ? err : data.mapped;
171}
172EXPORT_SYMBOL_GPL(xen_xlate_remap_gfn_array);
173
174static void unmap_gfn(unsigned long gfn, void *data)
175{
176 struct xen_remove_from_physmap xrp;
177
178 xrp.domid = DOMID_SELF;
179 xrp.gpfn = gfn;
180 (void)HYPERVISOR_memory_op(XENMEM_remove_from_physmap, &xrp);
181}
182
183int xen_xlate_unmap_gfn_range(struct vm_area_struct *vma,
184 int nr, struct page **pages)
185{
186 xen_for_each_gfn(pages, nr, unmap_gfn, NULL);
187
188 return 0;
189}
190EXPORT_SYMBOL_GPL(xen_xlate_unmap_gfn_range);
191
192struct map_balloon_pages {
193 xen_pfn_t *pfns;
194 unsigned int idx;
195};
196
197static void setup_balloon_gfn(unsigned long gfn, void *data)
198{
199 struct map_balloon_pages *info = data;
200
201 info->pfns[info->idx++] = gfn;
202}
203
204/**
205 * xen_xlate_map_ballooned_pages - map a new set of ballooned pages
206 * @gfns: returns the array of corresponding GFNs
207 * @virt: returns the virtual address of the mapped region
208 * @nr_grant_frames: number of GFNs
209 * @return 0 on success, error otherwise
210 *
211 * This allocates a set of ballooned pages and maps them into the
212 * kernel's address space.
213 */
214int __init xen_xlate_map_ballooned_pages(xen_pfn_t **gfns, void **virt,
215 unsigned long nr_grant_frames)
216{
217 struct page **pages;
218 xen_pfn_t *pfns;
219 void *vaddr;
220 struct map_balloon_pages data;
221 int rc;
222 unsigned long nr_pages;
223
224 BUG_ON(nr_grant_frames == 0);
225 nr_pages = DIV_ROUND_UP(nr_grant_frames, XEN_PFN_PER_PAGE);
226 pages = kzalloc_objs(pages[0], nr_pages);
227 if (!pages)
228 return -ENOMEM;
229
230 pfns = kzalloc_objs(pfns[0], nr_grant_frames);
231 if (!pfns) {
232 kfree(pages);
233 return -ENOMEM;
234 }
235 rc = xen_alloc_unpopulated_pages(nr_pages, pages);
236 if (rc) {
237 pr_warn("%s Couldn't balloon alloc %ld pages rc:%d\n", __func__,
238 nr_pages, rc);
239 kfree(pages);
240 kfree(pfns);
241 return rc;
242 }
243
244 data.pfns = pfns;
245 data.idx = 0;
246 xen_for_each_gfn(pages, nr_grant_frames, setup_balloon_gfn, &data);
247
248 vaddr = vmap(pages, nr_pages, 0, PAGE_KERNEL);
249 if (!vaddr) {
250 pr_warn("%s Couldn't map %ld pages rc:%d\n", __func__,
251 nr_pages, rc);
252 xen_free_unpopulated_pages(nr_pages, pages);
253 kfree(pages);
254 kfree(pfns);
255 return -ENOMEM;
256 }
257 kfree(pages);
258
259 *gfns = pfns;
260 *virt = vaddr;
261
262 return 0;
263}
264
265struct remap_pfn {
266 struct mm_struct *mm;
267 struct page **pages;
268 pgprot_t prot;
269 unsigned long i;
270};
271
272static int remap_pfn_fn(pte_t *ptep, unsigned long addr, void *data)
273{
274 struct remap_pfn *r = data;
275 struct page *page = r->pages[r->i];
276 pte_t pte = pte_mkspecial(pfn_pte(page_to_pfn(page), r->prot));
277
278 set_pte_at(r->mm, addr, ptep, pte);
279 r->i++;
280
281 return 0;
282}
283
284/* Used by the privcmd module, but has to be built-in on ARM */
285int xen_remap_vma_range(struct vm_area_struct *vma, unsigned long addr, unsigned long len)
286{
287 struct remap_pfn r = {
288 .mm = vma->vm_mm,
289 .pages = vma->vm_private_data,
290 .prot = vma->vm_page_prot,
291 };
292
293 return apply_to_page_range(vma->vm_mm, addr, len, remap_pfn_fn, &r);
294}
295EXPORT_SYMBOL_GPL(xen_remap_vma_range);