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 45 typedef 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 */ 48 static 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 64 struct 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 84 static 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 96 static 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 } 142 143 int 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 } 172 EXPORT_SYMBOL_GPL(xen_xlate_remap_gfn_array); 173 174 static 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 } 182 183 int 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 } 190 EXPORT_SYMBOL_GPL(xen_xlate_unmap_gfn_range); 191 192 struct map_balloon_pages { 193 xen_pfn_t *pfns; 194 unsigned int idx; 195 }; 196 197 static 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 */ 214 int __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 = kcalloc(nr_pages, sizeof(pages[0]), GFP_KERNEL); 227 if (!pages) 228 return -ENOMEM; 229 230 pfns = kcalloc(nr_grant_frames, sizeof(pfns[0]), GFP_KERNEL); 231 if (!pfns) { 232 kfree(pages); 233 return -ENOMEM; 234 } 235 rc = alloc_xenballooned_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 free_xenballooned_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 EXPORT_SYMBOL_GPL(xen_xlate_map_ballooned_pages); 265 266 struct remap_pfn { 267 struct mm_struct *mm; 268 struct page **pages; 269 pgprot_t prot; 270 unsigned long i; 271 }; 272 273 static int remap_pfn_fn(pte_t *ptep, unsigned long addr, void *data) 274 { 275 struct remap_pfn *r = data; 276 struct page *page = r->pages[r->i]; 277 pte_t pte = pte_mkspecial(pfn_pte(page_to_pfn(page), r->prot)); 278 279 set_pte_at(r->mm, addr, ptep, pte); 280 r->i++; 281 282 return 0; 283 } 284 285 /* Used by the privcmd module, but has to be built-in on ARM */ 286 int xen_remap_vma_range(struct vm_area_struct *vma, unsigned long addr, unsigned long len) 287 { 288 struct remap_pfn r = { 289 .mm = vma->vm_mm, 290 .pages = vma->vm_private_data, 291 .prot = vma->vm_page_prot, 292 }; 293 294 return apply_to_page_range(vma->vm_mm, addr, len, remap_pfn_fn, &r); 295 } 296 EXPORT_SYMBOL_GPL(xen_remap_vma_range); 297