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  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
 19static 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 */
 52int 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 */
 85int 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
108int 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
131int 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 */
156int 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
334unset_region:
335	kfree(regions_info);
336unmap_kernel_map:
337	mutex_lock(&vm->regions_mapping_lock);
338	vm->regions_mapping_count--;
339	mutex_unlock(&vm->regions_mapping_lock);
340unmap_no_count:
341	vunmap(remap_vaddr);
342put_pages:
343	for (i = 0; i < pinned; i++)
344		unpin_user_page(pages[i]);
345free_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 */
354void 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}