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/sched/signal.h> 28 #include <linux/hugetlb.h> 29 #include <linux/list.h> 30 #include <linux/anon_inodes.h> 31 32 #include <asm/tlbflush.h> 33 #include <asm/kvm_ppc.h> 34 #include <asm/kvm_book3s.h> 35 #include <asm/book3s/64/mmu-hash.h> 36 #include <asm/hvcall.h> 37 #include <asm/synch.h> 38 #include <asm/ppc-opcode.h> 39 #include <asm/kvm_host.h> 40 #include <asm/udbg.h> 41 #include <asm/iommu.h> 42 #include <asm/tce.h> 43 44 static unsigned long kvmppc_tce_pages(unsigned long iommu_pages) 45 { 46 return ALIGN(iommu_pages * sizeof(u64), PAGE_SIZE) / PAGE_SIZE; 47 } 48 49 static unsigned long kvmppc_stt_pages(unsigned long tce_pages) 50 { 51 unsigned long stt_bytes = sizeof(struct kvmppc_spapr_tce_table) + 52 (tce_pages * sizeof(struct page *)); 53 54 return tce_pages + ALIGN(stt_bytes, PAGE_SIZE) / PAGE_SIZE; 55 } 56 57 static long kvmppc_account_memlimit(unsigned long stt_pages, bool inc) 58 { 59 long ret = 0; 60 61 if (!current || !current->mm) 62 return ret; /* process exited */ 63 64 down_write(¤t->mm->mmap_sem); 65 66 if (inc) { 67 unsigned long locked, lock_limit; 68 69 locked = current->mm->locked_vm + stt_pages; 70 lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; 71 if (locked > lock_limit && !capable(CAP_IPC_LOCK)) 72 ret = -ENOMEM; 73 else 74 current->mm->locked_vm += stt_pages; 75 } else { 76 if (WARN_ON_ONCE(stt_pages > current->mm->locked_vm)) 77 stt_pages = current->mm->locked_vm; 78 79 current->mm->locked_vm -= stt_pages; 80 } 81 82 pr_debug("[%d] RLIMIT_MEMLOCK KVM %c%ld %ld/%ld%s\n", current->pid, 83 inc ? '+' : '-', 84 stt_pages << PAGE_SHIFT, 85 current->mm->locked_vm << PAGE_SHIFT, 86 rlimit(RLIMIT_MEMLOCK), 87 ret ? " - exceeded" : ""); 88 89 up_write(¤t->mm->mmap_sem); 90 91 return ret; 92 } 93 94 static void release_spapr_tce_table(struct rcu_head *head) 95 { 96 struct kvmppc_spapr_tce_table *stt = container_of(head, 97 struct kvmppc_spapr_tce_table, rcu); 98 unsigned long i, npages = kvmppc_tce_pages(stt->size); 99 100 for (i = 0; i < npages; i++) 101 __free_page(stt->pages[i]); 102 103 kfree(stt); 104 } 105 106 static int kvm_spapr_tce_fault(struct vm_fault *vmf) 107 { 108 struct kvmppc_spapr_tce_table *stt = vmf->vma->vm_file->private_data; 109 struct page *page; 110 111 if (vmf->pgoff >= kvmppc_tce_pages(stt->size)) 112 return VM_FAULT_SIGBUS; 113 114 page = stt->pages[vmf->pgoff]; 115 get_page(page); 116 vmf->page = page; 117 return 0; 118 } 119 120 static const struct vm_operations_struct kvm_spapr_tce_vm_ops = { 121 .fault = kvm_spapr_tce_fault, 122 }; 123 124 static int kvm_spapr_tce_mmap(struct file *file, struct vm_area_struct *vma) 125 { 126 vma->vm_ops = &kvm_spapr_tce_vm_ops; 127 return 0; 128 } 129 130 static int kvm_spapr_tce_release(struct inode *inode, struct file *filp) 131 { 132 struct kvmppc_spapr_tce_table *stt = filp->private_data; 133 134 list_del_rcu(&stt->list); 135 136 kvm_put_kvm(stt->kvm); 137 138 kvmppc_account_memlimit( 139 kvmppc_stt_pages(kvmppc_tce_pages(stt->size)), false); 140 call_rcu(&stt->rcu, release_spapr_tce_table); 141 142 return 0; 143 } 144 145 static const struct file_operations kvm_spapr_tce_fops = { 146 .mmap = kvm_spapr_tce_mmap, 147 .release = kvm_spapr_tce_release, 148 }; 149 150 long kvm_vm_ioctl_create_spapr_tce(struct kvm *kvm, 151 struct kvm_create_spapr_tce_64 *args) 152 { 153 struct kvmppc_spapr_tce_table *stt = NULL; 154 unsigned long npages, size; 155 int ret = -ENOMEM; 156 int i; 157 158 if (!args->size) 159 return -EINVAL; 160 161 /* Check this LIOBN hasn't been previously allocated */ 162 list_for_each_entry(stt, &kvm->arch.spapr_tce_tables, list) { 163 if (stt->liobn == args->liobn) 164 return -EBUSY; 165 } 166 167 size = args->size; 168 npages = kvmppc_tce_pages(size); 169 ret = kvmppc_account_memlimit(kvmppc_stt_pages(npages), true); 170 if (ret) { 171 stt = NULL; 172 goto fail; 173 } 174 175 ret = -ENOMEM; 176 stt = kzalloc(sizeof(*stt) + npages * sizeof(struct page *), 177 GFP_KERNEL); 178 if (!stt) 179 goto fail; 180 181 stt->liobn = args->liobn; 182 stt->page_shift = args->page_shift; 183 stt->offset = args->offset; 184 stt->size = size; 185 stt->kvm = kvm; 186 187 for (i = 0; i < npages; i++) { 188 stt->pages[i] = alloc_page(GFP_KERNEL | __GFP_ZERO); 189 if (!stt->pages[i]) 190 goto fail; 191 } 192 193 kvm_get_kvm(kvm); 194 195 mutex_lock(&kvm->lock); 196 list_add_rcu(&stt->list, &kvm->arch.spapr_tce_tables); 197 198 mutex_unlock(&kvm->lock); 199 200 return anon_inode_getfd("kvm-spapr-tce", &kvm_spapr_tce_fops, 201 stt, O_RDWR | O_CLOEXEC); 202 203 fail: 204 if (stt) { 205 for (i = 0; i < npages; i++) 206 if (stt->pages[i]) 207 __free_page(stt->pages[i]); 208 209 kfree(stt); 210 } 211 return ret; 212 } 213 214 long kvmppc_h_put_tce(struct kvm_vcpu *vcpu, unsigned long liobn, 215 unsigned long ioba, unsigned long tce) 216 { 217 struct kvmppc_spapr_tce_table *stt = kvmppc_find_table(vcpu, liobn); 218 long ret; 219 220 /* udbg_printf("H_PUT_TCE(): liobn=0x%lx ioba=0x%lx, tce=0x%lx\n", */ 221 /* liobn, ioba, tce); */ 222 223 if (!stt) 224 return H_TOO_HARD; 225 226 ret = kvmppc_ioba_validate(stt, ioba, 1); 227 if (ret != H_SUCCESS) 228 return ret; 229 230 ret = kvmppc_tce_validate(stt, tce); 231 if (ret != H_SUCCESS) 232 return ret; 233 234 kvmppc_tce_put(stt, ioba >> stt->page_shift, tce); 235 236 return H_SUCCESS; 237 } 238 EXPORT_SYMBOL_GPL(kvmppc_h_put_tce); 239 240 long kvmppc_h_put_tce_indirect(struct kvm_vcpu *vcpu, 241 unsigned long liobn, unsigned long ioba, 242 unsigned long tce_list, unsigned long npages) 243 { 244 struct kvmppc_spapr_tce_table *stt; 245 long i, ret = H_SUCCESS, idx; 246 unsigned long entry, ua = 0; 247 u64 __user *tces; 248 u64 tce; 249 250 stt = kvmppc_find_table(vcpu, liobn); 251 if (!stt) 252 return H_TOO_HARD; 253 254 entry = ioba >> stt->page_shift; 255 /* 256 * SPAPR spec says that the maximum size of the list is 512 TCEs 257 * so the whole table fits in 4K page 258 */ 259 if (npages > 512) 260 return H_PARAMETER; 261 262 if (tce_list & (SZ_4K - 1)) 263 return H_PARAMETER; 264 265 ret = kvmppc_ioba_validate(stt, ioba, npages); 266 if (ret != H_SUCCESS) 267 return ret; 268 269 idx = srcu_read_lock(&vcpu->kvm->srcu); 270 if (kvmppc_gpa_to_ua(vcpu->kvm, tce_list, &ua, NULL)) { 271 ret = H_TOO_HARD; 272 goto unlock_exit; 273 } 274 tces = (u64 __user *) ua; 275 276 for (i = 0; i < npages; ++i) { 277 if (get_user(tce, tces + i)) { 278 ret = H_TOO_HARD; 279 goto unlock_exit; 280 } 281 tce = be64_to_cpu(tce); 282 283 ret = kvmppc_tce_validate(stt, tce); 284 if (ret != H_SUCCESS) 285 goto unlock_exit; 286 287 kvmppc_tce_put(stt, entry + i, tce); 288 } 289 290 unlock_exit: 291 srcu_read_unlock(&vcpu->kvm->srcu, idx); 292 293 return ret; 294 } 295 EXPORT_SYMBOL_GPL(kvmppc_h_put_tce_indirect); 296 297 long kvmppc_h_stuff_tce(struct kvm_vcpu *vcpu, 298 unsigned long liobn, unsigned long ioba, 299 unsigned long tce_value, unsigned long npages) 300 { 301 struct kvmppc_spapr_tce_table *stt; 302 long i, ret; 303 304 stt = kvmppc_find_table(vcpu, liobn); 305 if (!stt) 306 return H_TOO_HARD; 307 308 ret = kvmppc_ioba_validate(stt, ioba, npages); 309 if (ret != H_SUCCESS) 310 return ret; 311 312 /* Check permission bits only to allow userspace poison TCE for debug */ 313 if (tce_value & (TCE_PCI_WRITE | TCE_PCI_READ)) 314 return H_PARAMETER; 315 316 for (i = 0; i < npages; ++i, ioba += (1ULL << stt->page_shift)) 317 kvmppc_tce_put(stt, ioba >> stt->page_shift, tce_value); 318 319 return H_SUCCESS; 320 } 321 EXPORT_SYMBOL_GPL(kvmppc_h_stuff_tce); 322