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/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(&current->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(&current->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 = _ALIGN_UP(args->size, PAGE_SIZE >> 3);
 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);