1 /*
2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License, version 2, as
4 * published by the Free Software Foundation.
5 *
6 * This program is distributed in the hope that it will be useful,
7 * but WITHOUT ANY WARRANTY; without even the implied warranty of
8 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
9 * GNU General Public License for more details.
10 *
11 * You should have received a copy of the GNU General Public License
12 * along with this program; if not, write to the Free Software
13 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
14 *
15 * Copyright 2010 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
16 * Copyright 2011 David Gibson, IBM Corporation <dwg@au1.ibm.com>
17 * Copyright 2016 Alexey Kardashevskiy, IBM Corporation <aik@au1.ibm.com>
18 */
19
20 #include <linux/types.h>
21 #include <linux/string.h>
22 #include <linux/kvm.h>
23 #include <linux/kvm_host.h>
24 #include <linux/highmem.h>
25 #include <linux/gfp.h>
26 #include <linux/slab.h>
27 #include <linux/hugetlb.h>
28 #include <linux/list.h>
29 #include <linux/anon_inodes.h>
30
31 #include <asm/tlbflush.h>
32 #include <asm/kvm_ppc.h>
33 #include <asm/kvm_book3s.h>
34 #include <asm/book3s/64/mmu-hash.h>
35 #include <asm/hvcall.h>
36 #include <asm/synch.h>
37 #include <asm/ppc-opcode.h>
38 #include <asm/kvm_host.h>
39 #include <asm/udbg.h>
40 #include <asm/iommu.h>
41 #include <asm/tce.h>
42
kvmppc_tce_pages(unsigned long iommu_pages)43 static unsigned long kvmppc_tce_pages(unsigned long iommu_pages)
44 {
45 return ALIGN(iommu_pages * sizeof(u64), PAGE_SIZE) / PAGE_SIZE;
46 }
47
kvmppc_stt_pages(unsigned long tce_pages)48 static unsigned long kvmppc_stt_pages(unsigned long tce_pages)
49 {
50 unsigned long stt_bytes = sizeof(struct kvmppc_spapr_tce_table) +
51 (tce_pages * sizeof(struct page *));
52
53 return tce_pages + ALIGN(stt_bytes, PAGE_SIZE) / PAGE_SIZE;
54 }
55
kvmppc_account_memlimit(unsigned long stt_pages,bool inc)56 static long kvmppc_account_memlimit(unsigned long stt_pages, bool inc)
57 {
58 long ret = 0;
59
60 if (!current || !current->mm)
61 return ret; /* process exited */
62
63 down_write(¤t->mm->mmap_sem);
64
65 if (inc) {
66 unsigned long locked, lock_limit;
67
68 locked = current->mm->locked_vm + stt_pages;
69 lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
70 if (locked > lock_limit && !capable(CAP_IPC_LOCK))
71 ret = -ENOMEM;
72 else
73 current->mm->locked_vm += stt_pages;
74 } else {
75 if (WARN_ON_ONCE(stt_pages > current->mm->locked_vm))
76 stt_pages = current->mm->locked_vm;
77
78 current->mm->locked_vm -= stt_pages;
79 }
80
81 pr_debug("[%d] RLIMIT_MEMLOCK KVM %c%ld %ld/%ld%s\n", current->pid,
82 inc ? '+' : '-',
83 stt_pages << PAGE_SHIFT,
84 current->mm->locked_vm << PAGE_SHIFT,
85 rlimit(RLIMIT_MEMLOCK),
86 ret ? " - exceeded" : "");
87
88 up_write(¤t->mm->mmap_sem);
89
90 return ret;
91 }
92
release_spapr_tce_table(struct rcu_head * head)93 static void release_spapr_tce_table(struct rcu_head *head)
94 {
95 struct kvmppc_spapr_tce_table *stt = container_of(head,
96 struct kvmppc_spapr_tce_table, rcu);
97 unsigned long i, npages = kvmppc_tce_pages(stt->size);
98
99 for (i = 0; i < npages; i++)
100 __free_page(stt->pages[i]);
101
102 kfree(stt);
103 }
104
kvm_spapr_tce_fault(struct vm_area_struct * vma,struct vm_fault * vmf)105 static int kvm_spapr_tce_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
106 {
107 struct kvmppc_spapr_tce_table *stt = vma->vm_file->private_data;
108 struct page *page;
109
110 if (vmf->pgoff >= kvmppc_tce_pages(stt->size))
111 return VM_FAULT_SIGBUS;
112
113 page = stt->pages[vmf->pgoff];
114 get_page(page);
115 vmf->page = page;
116 return 0;
117 }
118
119 static const struct vm_operations_struct kvm_spapr_tce_vm_ops = {
120 .fault = kvm_spapr_tce_fault,
121 };
122
kvm_spapr_tce_mmap(struct file * file,struct vm_area_struct * vma)123 static int kvm_spapr_tce_mmap(struct file *file, struct vm_area_struct *vma)
124 {
125 vma->vm_ops = &kvm_spapr_tce_vm_ops;
126 return 0;
127 }
128
kvm_spapr_tce_release(struct inode * inode,struct file * filp)129 static int kvm_spapr_tce_release(struct inode *inode, struct file *filp)
130 {
131 struct kvmppc_spapr_tce_table *stt = filp->private_data;
132 struct kvm *kvm = stt->kvm;
133
134 mutex_lock(&kvm->lock);
135 list_del_rcu(&stt->list);
136 mutex_unlock(&kvm->lock);
137
138 kvm_put_kvm(stt->kvm);
139
140 kvmppc_account_memlimit(
141 kvmppc_stt_pages(kvmppc_tce_pages(stt->size)), false);
142 call_rcu(&stt->rcu, release_spapr_tce_table);
143
144 return 0;
145 }
146
147 static const struct file_operations kvm_spapr_tce_fops = {
148 .mmap = kvm_spapr_tce_mmap,
149 .release = kvm_spapr_tce_release,
150 };
151
kvm_vm_ioctl_create_spapr_tce(struct kvm * kvm,struct kvm_create_spapr_tce_64 * args)152 long kvm_vm_ioctl_create_spapr_tce(struct kvm *kvm,
153 struct kvm_create_spapr_tce_64 *args)
154 {
155 struct kvmppc_spapr_tce_table *stt = NULL;
156 struct kvmppc_spapr_tce_table *siter;
157 unsigned long npages, size;
158 int ret = -ENOMEM;
159 int i;
160
161 if (!args->size)
162 return -EINVAL;
163
164 size = args->size;
165 npages = kvmppc_tce_pages(size);
166 ret = kvmppc_account_memlimit(kvmppc_stt_pages(npages), true);
167 if (ret)
168 return ret;
169
170 stt = kzalloc(sizeof(*stt) + npages * sizeof(struct page *),
171 GFP_KERNEL);
172 if (!stt)
173 goto fail_acct;
174
175 stt->liobn = args->liobn;
176 stt->page_shift = args->page_shift;
177 stt->offset = args->offset;
178 stt->size = size;
179 stt->kvm = kvm;
180
181 for (i = 0; i < npages; i++) {
182 stt->pages[i] = alloc_page(GFP_KERNEL | __GFP_ZERO);
183 if (!stt->pages[i])
184 goto fail;
185 }
186
187 mutex_lock(&kvm->lock);
188
189 /* Check this LIOBN hasn't been previously allocated */
190 ret = 0;
191 list_for_each_entry(siter, &kvm->arch.spapr_tce_tables, list) {
192 if (siter->liobn == args->liobn) {
193 ret = -EBUSY;
194 break;
195 }
196 }
197
198 if (!ret)
199 ret = anon_inode_getfd("kvm-spapr-tce", &kvm_spapr_tce_fops,
200 stt, O_RDWR | O_CLOEXEC);
201
202 if (ret >= 0) {
203 list_add_rcu(&stt->list, &kvm->arch.spapr_tce_tables);
204 kvm_get_kvm(kvm);
205 }
206
207 mutex_unlock(&kvm->lock);
208
209 if (ret >= 0)
210 return ret;
211
212 fail:
213 for (i = 0; i < npages; i++)
214 if (stt->pages[i])
215 __free_page(stt->pages[i]);
216
217 kfree(stt);
218 fail_acct:
219 kvmppc_account_memlimit(kvmppc_stt_pages(npages), false);
220 return ret;
221 }
222
kvmppc_h_put_tce(struct kvm_vcpu * vcpu,unsigned long liobn,unsigned long ioba,unsigned long tce)223 long kvmppc_h_put_tce(struct kvm_vcpu *vcpu, unsigned long liobn,
224 unsigned long ioba, unsigned long tce)
225 {
226 struct kvmppc_spapr_tce_table *stt = kvmppc_find_table(vcpu, liobn);
227 long ret;
228
229 /* udbg_printf("H_PUT_TCE(): liobn=0x%lx ioba=0x%lx, tce=0x%lx\n", */
230 /* liobn, ioba, tce); */
231
232 if (!stt)
233 return H_TOO_HARD;
234
235 ret = kvmppc_ioba_validate(stt, ioba, 1);
236 if (ret != H_SUCCESS)
237 return ret;
238
239 ret = kvmppc_tce_validate(stt, tce);
240 if (ret != H_SUCCESS)
241 return ret;
242
243 kvmppc_tce_put(stt, ioba >> stt->page_shift, tce);
244
245 return H_SUCCESS;
246 }
247 EXPORT_SYMBOL_GPL(kvmppc_h_put_tce);
248
kvmppc_h_put_tce_indirect(struct kvm_vcpu * vcpu,unsigned long liobn,unsigned long ioba,unsigned long tce_list,unsigned long npages)249 long kvmppc_h_put_tce_indirect(struct kvm_vcpu *vcpu,
250 unsigned long liobn, unsigned long ioba,
251 unsigned long tce_list, unsigned long npages)
252 {
253 struct kvmppc_spapr_tce_table *stt;
254 long i, ret = H_SUCCESS, idx;
255 unsigned long entry, ua = 0;
256 u64 __user *tces;
257 u64 tce;
258
259 stt = kvmppc_find_table(vcpu, liobn);
260 if (!stt)
261 return H_TOO_HARD;
262
263 entry = ioba >> stt->page_shift;
264 /*
265 * SPAPR spec says that the maximum size of the list is 512 TCEs
266 * so the whole table fits in 4K page
267 */
268 if (npages > 512)
269 return H_PARAMETER;
270
271 if (tce_list & (SZ_4K - 1))
272 return H_PARAMETER;
273
274 ret = kvmppc_ioba_validate(stt, ioba, npages);
275 if (ret != H_SUCCESS)
276 return ret;
277
278 idx = srcu_read_lock(&vcpu->kvm->srcu);
279 if (kvmppc_gpa_to_ua(vcpu->kvm, tce_list, &ua, NULL)) {
280 ret = H_TOO_HARD;
281 goto unlock_exit;
282 }
283 tces = (u64 __user *) ua;
284
285 for (i = 0; i < npages; ++i) {
286 if (get_user(tce, tces + i)) {
287 ret = H_TOO_HARD;
288 goto unlock_exit;
289 }
290 tce = be64_to_cpu(tce);
291
292 ret = kvmppc_tce_validate(stt, tce);
293 if (ret != H_SUCCESS)
294 goto unlock_exit;
295
296 kvmppc_tce_put(stt, entry + i, tce);
297 }
298
299 unlock_exit:
300 srcu_read_unlock(&vcpu->kvm->srcu, idx);
301
302 return ret;
303 }
304 EXPORT_SYMBOL_GPL(kvmppc_h_put_tce_indirect);
305
kvmppc_h_stuff_tce(struct kvm_vcpu * vcpu,unsigned long liobn,unsigned long ioba,unsigned long tce_value,unsigned long npages)306 long kvmppc_h_stuff_tce(struct kvm_vcpu *vcpu,
307 unsigned long liobn, unsigned long ioba,
308 unsigned long tce_value, unsigned long npages)
309 {
310 struct kvmppc_spapr_tce_table *stt;
311 long i, ret;
312
313 stt = kvmppc_find_table(vcpu, liobn);
314 if (!stt)
315 return H_TOO_HARD;
316
317 ret = kvmppc_ioba_validate(stt, ioba, npages);
318 if (ret != H_SUCCESS)
319 return ret;
320
321 /* Check permission bits only to allow userspace poison TCE for debug */
322 if (tce_value & (TCE_PCI_WRITE | TCE_PCI_READ))
323 return H_PARAMETER;
324
325 for (i = 0; i < npages; ++i, ioba += (1ULL << stt->page_shift))
326 kvmppc_tce_put(stt, ioba >> stt->page_shift, tce_value);
327
328 return H_SUCCESS;
329 }
330 EXPORT_SYMBOL_GPL(kvmppc_h_stuff_tce);
331