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, pgtable_t token, unsigned long addr,
97 void *data)
98{
99 struct remap_data *info = data;
100 struct page *page = info->pages[info->index++];
101 pte_t pte = pte_mkspecial(pfn_pte(page_to_pfn(page), info->prot));
102 int rc, nr_gfn;
103 uint32_t i;
104 struct xen_add_to_physmap_range xatp = {
105 .domid = DOMID_SELF,
106 .foreign_domid = info->domid,
107 .space = XENMAPSPACE_gmfn_foreign,
108 };
109
110 nr_gfn = min_t(typeof(info->nr_fgfn), XEN_PFN_PER_PAGE, info->nr_fgfn);
111 info->nr_fgfn -= nr_gfn;
112
113 info->h_iter = 0;
114 xen_for_each_gfn(&page, nr_gfn, setup_hparams, info);
115 BUG_ON(info->h_iter != nr_gfn);
116
117 set_xen_guest_handle(xatp.idxs, info->h_idxs);
118 set_xen_guest_handle(xatp.gpfns, info->h_gpfns);
119 set_xen_guest_handle(xatp.errs, info->h_errs);
120 xatp.size = nr_gfn;
121
122 rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap_range, &xatp);
123
124 /* info->err_ptr expect to have one error status per Xen PFN */
125 for (i = 0; i < nr_gfn; i++) {
126 int err = (rc < 0) ? rc : info->h_errs[i];
127
128 *(info->err_ptr++) = err;
129 if (!err)
130 info->mapped++;
131 }
132
133 /*
134 * Note: The hypercall will return 0 in most of the case if even if
135 * all the fgmfn are not mapped. We still have to update the pte
136 * as the userspace may decide to continue.
137 */
138 if (!rc)
139 set_pte_at(info->vma->vm_mm, addr, ptep, pte);
140
141 return 0;
142}
143
144int xen_xlate_remap_gfn_array(struct vm_area_struct *vma,
145 unsigned long addr,
146 xen_pfn_t *gfn, int nr,
147 int *err_ptr, pgprot_t prot,
148 unsigned domid,
149 struct page **pages)
150{
151 int err;
152 struct remap_data data;
153 unsigned long range = DIV_ROUND_UP(nr, XEN_PFN_PER_PAGE) << PAGE_SHIFT;
154
155 /* Kept here for the purpose of making sure code doesn't break
156 x86 PVOPS */
157 BUG_ON(!((vma->vm_flags & (VM_PFNMAP | VM_IO)) == (VM_PFNMAP | VM_IO)));
158
159 data.fgfn = gfn;
160 data.nr_fgfn = nr;
161 data.prot = prot;
162 data.domid = domid;
163 data.vma = vma;
164 data.pages = pages;
165 data.index = 0;
166 data.err_ptr = err_ptr;
167 data.mapped = 0;
168
169 err = apply_to_page_range(vma->vm_mm, addr, range,
170 remap_pte_fn, &data);
171 return err < 0 ? err : data.mapped;
172}
173EXPORT_SYMBOL_GPL(xen_xlate_remap_gfn_array);
174
175static void unmap_gfn(unsigned long gfn, void *data)
176{
177 struct xen_remove_from_physmap xrp;
178
179 xrp.domid = DOMID_SELF;
180 xrp.gpfn = gfn;
181 (void)HYPERVISOR_memory_op(XENMEM_remove_from_physmap, &xrp);
182}
183
184int xen_xlate_unmap_gfn_range(struct vm_area_struct *vma,
185 int nr, struct page **pages)
186{
187 xen_for_each_gfn(pages, nr, unmap_gfn, NULL);
188
189 return 0;
190}
191EXPORT_SYMBOL_GPL(xen_xlate_unmap_gfn_range);
192
193struct map_balloon_pages {
194 xen_pfn_t *pfns;
195 unsigned int idx;
196};
197
198static void setup_balloon_gfn(unsigned long gfn, void *data)
199{
200 struct map_balloon_pages *info = data;
201
202 info->pfns[info->idx++] = gfn;
203}
204
205/**
206 * xen_xlate_map_ballooned_pages - map a new set of ballooned pages
207 * @gfns: returns the array of corresponding GFNs
208 * @virt: returns the virtual address of the mapped region
209 * @nr_grant_frames: number of GFNs
210 * @return 0 on success, error otherwise
211 *
212 * This allocates a set of ballooned pages and maps them into the
213 * kernel's address space.
214 */
215int __init xen_xlate_map_ballooned_pages(xen_pfn_t **gfns, void **virt,
216 unsigned long nr_grant_frames)
217{
218 struct page **pages;
219 xen_pfn_t *pfns;
220 void *vaddr;
221 struct map_balloon_pages data;
222 int rc;
223 unsigned long nr_pages;
224
225 BUG_ON(nr_grant_frames == 0);
226 nr_pages = DIV_ROUND_UP(nr_grant_frames, XEN_PFN_PER_PAGE);
227 pages = kcalloc(nr_pages, sizeof(pages[0]), GFP_KERNEL);
228 if (!pages)
229 return -ENOMEM;
230
231 pfns = kcalloc(nr_grant_frames, sizeof(pfns[0]), GFP_KERNEL);
232 if (!pfns) {
233 kfree(pages);
234 return -ENOMEM;
235 }
236 rc = alloc_xenballooned_pages(nr_pages, pages);
237 if (rc) {
238 pr_warn("%s Couldn't balloon alloc %ld pages rc:%d\n", __func__,
239 nr_pages, rc);
240 kfree(pages);
241 kfree(pfns);
242 return rc;
243 }
244
245 data.pfns = pfns;
246 data.idx = 0;
247 xen_for_each_gfn(pages, nr_grant_frames, setup_balloon_gfn, &data);
248
249 vaddr = vmap(pages, nr_pages, 0, PAGE_KERNEL);
250 if (!vaddr) {
251 pr_warn("%s Couldn't map %ld pages rc:%d\n", __func__,
252 nr_pages, rc);
253 free_xenballooned_pages(nr_pages, pages);
254 kfree(pages);
255 kfree(pfns);
256 return -ENOMEM;
257 }
258 kfree(pages);
259
260 *gfns = pfns;
261 *virt = vaddr;
262
263 return 0;
264}
265EXPORT_SYMBOL_GPL(xen_xlate_map_ballooned_pages);
266