xref: /linux/drivers/virt/acrn/mm.c (revision 39c089a01a7e431383710a566864644cbbc0f8fe)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * ACRN: Memory mapping management
4  *
5  * Copyright (C) 2020 Intel Corporation. All rights reserved.
6  *
7  * Authors:
8  *	Fei Li <lei1.li@intel.com>
9  *	Shuo Liu <shuo.a.liu@intel.com>
10  */
11 
12 #include <linux/io.h>
13 #include <linux/mm.h>
14 #include <linux/slab.h>
15 #include <linux/vmalloc.h>
16 
17 #include "acrn_drv.h"
18 
19 static int modify_region(struct acrn_vm *vm, struct vm_memory_region_op *region)
20 {
21 	struct vm_memory_region_batch *regions;
22 	int ret;
23 
24 	regions = kzalloc(sizeof(*regions), GFP_KERNEL);
25 	if (!regions)
26 		return -ENOMEM;
27 
28 	regions->vmid = vm->vmid;
29 	regions->regions_num = 1;
30 	regions->regions_gpa = virt_to_phys(region);
31 
32 	ret = hcall_set_memory_regions(virt_to_phys(regions));
33 	if (ret < 0)
34 		dev_dbg(acrn_dev.this_device,
35 			"Failed to set memory region for VM[%u]!\n", vm->vmid);
36 
37 	kfree(regions);
38 	return ret;
39 }
40 
41 /**
42  * acrn_mm_region_add() - Set up the EPT mapping of a memory region.
43  * @vm:			User VM.
44  * @user_gpa:		A GPA of User VM.
45  * @service_gpa:	A GPA of Service VM.
46  * @size:		Size of the region.
47  * @mem_type:		Combination of ACRN_MEM_TYPE_*.
48  * @mem_access_right:	Combination of ACRN_MEM_ACCESS_*.
49  *
50  * Return: 0 on success, <0 on error.
51  */
52 int acrn_mm_region_add(struct acrn_vm *vm, u64 user_gpa, u64 service_gpa,
53 		       u64 size, u32 mem_type, u32 mem_access_right)
54 {
55 	struct vm_memory_region_op *region;
56 	int ret = 0;
57 
58 	region = kzalloc(sizeof(*region), GFP_KERNEL);
59 	if (!region)
60 		return -ENOMEM;
61 
62 	region->type = ACRN_MEM_REGION_ADD;
63 	region->user_vm_pa = user_gpa;
64 	region->service_vm_pa = service_gpa;
65 	region->size = size;
66 	region->attr = ((mem_type & ACRN_MEM_TYPE_MASK) |
67 			(mem_access_right & ACRN_MEM_ACCESS_RIGHT_MASK));
68 	ret = modify_region(vm, region);
69 
70 	dev_dbg(acrn_dev.this_device,
71 		"%s: user-GPA[%pK] service-GPA[%pK] size[0x%llx].\n",
72 		__func__, (void *)user_gpa, (void *)service_gpa, size);
73 	kfree(region);
74 	return ret;
75 }
76 
77 /**
78  * acrn_mm_region_del() - Del the EPT mapping of a memory region.
79  * @vm:		User VM.
80  * @user_gpa:	A GPA of the User VM.
81  * @size:	Size of the region.
82  *
83  * Return: 0 on success, <0 for error.
84  */
85 int acrn_mm_region_del(struct acrn_vm *vm, u64 user_gpa, u64 size)
86 {
87 	struct vm_memory_region_op *region;
88 	int ret = 0;
89 
90 	region = kzalloc(sizeof(*region), GFP_KERNEL);
91 	if (!region)
92 		return -ENOMEM;
93 
94 	region->type = ACRN_MEM_REGION_DEL;
95 	region->user_vm_pa = user_gpa;
96 	region->service_vm_pa = 0UL;
97 	region->size = size;
98 	region->attr = 0U;
99 
100 	ret = modify_region(vm, region);
101 
102 	dev_dbg(acrn_dev.this_device, "%s: user-GPA[%pK] size[0x%llx].\n",
103 		__func__, (void *)user_gpa, size);
104 	kfree(region);
105 	return ret;
106 }
107 
108 int acrn_vm_memseg_map(struct acrn_vm *vm, struct acrn_vm_memmap *memmap)
109 {
110 	int ret;
111 
112 	if (memmap->type == ACRN_MEMMAP_RAM)
113 		return acrn_vm_ram_map(vm, memmap);
114 
115 	if (memmap->type != ACRN_MEMMAP_MMIO) {
116 		dev_dbg(acrn_dev.this_device,
117 			"Invalid memmap type: %u\n", memmap->type);
118 		return -EINVAL;
119 	}
120 
121 	ret = acrn_mm_region_add(vm, memmap->user_vm_pa,
122 				 memmap->service_vm_pa, memmap->len,
123 				 ACRN_MEM_TYPE_UC, memmap->attr);
124 	if (ret < 0)
125 		dev_dbg(acrn_dev.this_device,
126 			"Add memory region failed, VM[%u]!\n", vm->vmid);
127 
128 	return ret;
129 }
130 
131 int acrn_vm_memseg_unmap(struct acrn_vm *vm, struct acrn_vm_memmap *memmap)
132 {
133 	int ret;
134 
135 	if (memmap->type != ACRN_MEMMAP_MMIO) {
136 		dev_dbg(acrn_dev.this_device,
137 			"Invalid memmap type: %u\n", memmap->type);
138 		return -EINVAL;
139 	}
140 
141 	ret = acrn_mm_region_del(vm, memmap->user_vm_pa, memmap->len);
142 	if (ret < 0)
143 		dev_dbg(acrn_dev.this_device,
144 			"Del memory region failed, VM[%u]!\n", vm->vmid);
145 
146 	return ret;
147 }
148 
149 /**
150  * acrn_vm_ram_map() - Create a RAM EPT mapping of User VM.
151  * @vm:		The User VM pointer
152  * @memmap:	Info of the EPT mapping
153  *
154  * Return: 0 on success, <0 for error.
155  */
156 int acrn_vm_ram_map(struct acrn_vm *vm, struct acrn_vm_memmap *memmap)
157 {
158 	struct vm_memory_region_batch *regions_info;
159 	int nr_pages, i, order, nr_regions = 0;
160 	struct vm_memory_mapping *region_mapping;
161 	struct vm_memory_region_op *vm_region;
162 	struct page **pages = NULL, *page;
163 	void *remap_vaddr;
164 	int ret, pinned;
165 	u64 user_vm_pa;
166 	struct vm_area_struct *vma;
167 
168 	if (!vm || !memmap)
169 		return -EINVAL;
170 
171 	/* Get the page number of the map region */
172 	nr_pages = memmap->len >> PAGE_SHIFT;
173 	if (!nr_pages)
174 		return -EINVAL;
175 
176 	mmap_read_lock(current->mm);
177 	vma = vma_lookup(current->mm, memmap->vma_base);
178 	if (vma && ((vma->vm_flags & VM_PFNMAP) != 0)) {
179 		unsigned long start_pfn, cur_pfn;
180 		bool writable;
181 
182 		if ((memmap->vma_base + memmap->len) > vma->vm_end) {
183 			mmap_read_unlock(current->mm);
184 			return -EINVAL;
185 		}
186 
187 		for (i = 0; i < nr_pages; i++) {
188 			struct follow_pfnmap_args args = {
189 				.vma = vma,
190 				.address = memmap->vma_base + i * PAGE_SIZE,
191 			};
192 
193 			ret = follow_pfnmap_start(&args);
194 			if (ret)
195 				break;
196 
197 			cur_pfn = args.pfn;
198 			if (i == 0)
199 				start_pfn = cur_pfn;
200 			writable = args.writable;
201 			follow_pfnmap_end(&args);
202 
203 			/* Disallow write access if the PTE is not writable. */
204 			if (!writable &&
205 			    (memmap->attr & ACRN_MEM_ACCESS_WRITE)) {
206 				ret = -EFAULT;
207 				break;
208 			}
209 
210 			/* Disallow refcounted pages. */
211 			if (pfn_valid(cur_pfn) &&
212 			    !PageReserved(pfn_to_page(cur_pfn))) {
213 				ret = -EFAULT;
214 				break;
215 			}
216 
217 			/* Disallow non-contiguous ranges. */
218 			if (cur_pfn != start_pfn + i) {
219 				ret = -EINVAL;
220 				break;
221 			}
222 		}
223 		mmap_read_unlock(current->mm);
224 
225 		if (ret) {
226 			dev_dbg(acrn_dev.this_device,
227 				"Failed to lookup PFN at VMA:%pK.\n", (void *)memmap->vma_base);
228 			return ret;
229 		}
230 
231 		return acrn_mm_region_add(vm, memmap->user_vm_pa,
232 			 PFN_PHYS(start_pfn), memmap->len,
233 			 ACRN_MEM_TYPE_WB, memmap->attr);
234 	}
235 	mmap_read_unlock(current->mm);
236 
237 	pages = vzalloc(array_size(nr_pages, sizeof(*pages)));
238 	if (!pages)
239 		return -ENOMEM;
240 
241 	/* Lock the pages of user memory map region */
242 	pinned = pin_user_pages_fast(memmap->vma_base,
243 				     nr_pages, FOLL_WRITE | FOLL_LONGTERM,
244 				     pages);
245 	if (pinned < 0) {
246 		ret = pinned;
247 		goto free_pages;
248 	} else if (pinned != nr_pages) {
249 		ret = -EFAULT;
250 		goto put_pages;
251 	}
252 
253 	/* Create a kernel map for the map region */
254 	remap_vaddr = vmap(pages, nr_pages, VM_MAP, PAGE_KERNEL);
255 	if (!remap_vaddr) {
256 		ret = -ENOMEM;
257 		goto put_pages;
258 	}
259 
260 	/* Record Service VM va <-> User VM pa mapping */
261 	mutex_lock(&vm->regions_mapping_lock);
262 	region_mapping = &vm->regions_mapping[vm->regions_mapping_count];
263 	if (vm->regions_mapping_count < ACRN_MEM_MAPPING_MAX) {
264 		region_mapping->pages = pages;
265 		region_mapping->npages = nr_pages;
266 		region_mapping->size = memmap->len;
267 		region_mapping->service_vm_va = remap_vaddr;
268 		region_mapping->user_vm_pa = memmap->user_vm_pa;
269 		vm->regions_mapping_count++;
270 	} else {
271 		dev_warn(acrn_dev.this_device,
272 			"Run out of memory mapping slots!\n");
273 		ret = -ENOMEM;
274 		mutex_unlock(&vm->regions_mapping_lock);
275 		goto unmap_no_count;
276 	}
277 	mutex_unlock(&vm->regions_mapping_lock);
278 
279 	/* Calculate count of vm_memory_region_op */
280 	for (i = 0; i < nr_pages; i += 1 << order) {
281 		page = pages[i];
282 		VM_BUG_ON_PAGE(PageTail(page), page);
283 		order = compound_order(page);
284 		nr_regions++;
285 	}
286 
287 	/* Prepare the vm_memory_region_batch */
288 	regions_info = kzalloc(struct_size(regions_info, regions_op,
289 					   nr_regions), GFP_KERNEL);
290 	if (!regions_info) {
291 		ret = -ENOMEM;
292 		goto unmap_kernel_map;
293 	}
294 	regions_info->regions_num = nr_regions;
295 
296 	/* Fill each vm_memory_region_op */
297 	vm_region = regions_info->regions_op;
298 	regions_info->vmid = vm->vmid;
299 	regions_info->regions_gpa = virt_to_phys(vm_region);
300 	user_vm_pa = memmap->user_vm_pa;
301 	for (i = 0; i < nr_pages; i += 1 << order) {
302 		u32 region_size;
303 
304 		page = pages[i];
305 		VM_BUG_ON_PAGE(PageTail(page), page);
306 		order = compound_order(page);
307 		region_size = PAGE_SIZE << order;
308 		vm_region->type = ACRN_MEM_REGION_ADD;
309 		vm_region->user_vm_pa = user_vm_pa;
310 		vm_region->service_vm_pa = page_to_phys(page);
311 		vm_region->size = region_size;
312 		vm_region->attr = (ACRN_MEM_TYPE_WB & ACRN_MEM_TYPE_MASK) |
313 				  (memmap->attr & ACRN_MEM_ACCESS_RIGHT_MASK);
314 
315 		vm_region++;
316 		user_vm_pa += region_size;
317 	}
318 
319 	/* Inform the ACRN Hypervisor to set up EPT mappings */
320 	ret = hcall_set_memory_regions(virt_to_phys(regions_info));
321 	if (ret < 0) {
322 		dev_dbg(acrn_dev.this_device,
323 			"Failed to set regions, VM[%u]!\n", vm->vmid);
324 		goto unset_region;
325 	}
326 	kfree(regions_info);
327 
328 	dev_dbg(acrn_dev.this_device,
329 		"%s: VM[%u] service-GVA[%pK] user-GPA[%pK] size[0x%llx]\n",
330 		__func__, vm->vmid,
331 		remap_vaddr, (void *)memmap->user_vm_pa, memmap->len);
332 	return ret;
333 
334 unset_region:
335 	kfree(regions_info);
336 unmap_kernel_map:
337 	mutex_lock(&vm->regions_mapping_lock);
338 	vm->regions_mapping_count--;
339 	mutex_unlock(&vm->regions_mapping_lock);
340 unmap_no_count:
341 	vunmap(remap_vaddr);
342 put_pages:
343 	for (i = 0; i < pinned; i++)
344 		unpin_user_page(pages[i]);
345 free_pages:
346 	vfree(pages);
347 	return ret;
348 }
349 
350 /**
351  * acrn_vm_all_ram_unmap() - Destroy a RAM EPT mapping of User VM.
352  * @vm:	The User VM
353  */
354 void acrn_vm_all_ram_unmap(struct acrn_vm *vm)
355 {
356 	struct vm_memory_mapping *region_mapping;
357 	int i, j;
358 
359 	mutex_lock(&vm->regions_mapping_lock);
360 	for (i = 0; i < vm->regions_mapping_count; i++) {
361 		region_mapping = &vm->regions_mapping[i];
362 		vunmap(region_mapping->service_vm_va);
363 		for (j = 0; j < region_mapping->npages; j++)
364 			unpin_user_page(region_mapping->pages[j]);
365 		vfree(region_mapping->pages);
366 	}
367 	mutex_unlock(&vm->regions_mapping_lock);
368 }
369