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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/or7 * modify it under the terms of the GNU General Public License version 28 * as published by the Free Software Foundation; or, when distributed9 * separately from the Linux kernel or incorporated into other10 * software packages, subject to the following license:11 *12 * Permission is hereby granted, free of charge, to any person obtaining a copy13 * of this source file (the "Software"), to deal in the Software without14 * 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 to17 * the following conditions:18 *19 * The above copyright notice and this permission notice shall be included in20 * all copies or substantial portions of the Software.21 *22 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR23 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,24 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE25 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER26 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING27 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS28 * 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 if134 * all the fgmfn are not mapped. We still have to update the pte135 * 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 break155 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 pages206 * @gfns: returns the array of corresponding GFNs207 * @virt: returns the virtual address of the mapped region208 * @nr_grant_frames: number of GFNs209 * @return 0 on success, error otherwise210 *211 * This allocates a set of ballooned pages and maps them into the212 * 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 = 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 = 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);296