arch/powerpc/kvm/book3s_64_vio.c

   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
  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
  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
  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(&current->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(&current->mm->mmap_sem);
  89
  90         return ret;
  91 }
  92
  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
 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
 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
 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
 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
 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
 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
 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);