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
 133         list_del_rcu(&stt->list);
 134
 135         kvm_put_kvm(stt->kvm);
 136
 137         kvmppc_account_memlimit(
 138                 kvmppc_stt_pages(kvmppc_tce_pages(stt->size)), false);
 139         call_rcu(&stt->rcu, release_spapr_tce_table);
 140
 141         return 0;
 142 }
 143
 144 static const struct file_operations kvm_spapr_tce_fops = {
 145         .mmap           = kvm_spapr_tce_mmap,
 146         .release        = kvm_spapr_tce_release,
 147 };
 148
 149 long kvm_vm_ioctl_create_spapr_tce(struct kvm *kvm,
 150                                    struct kvm_create_spapr_tce_64 *args)
 151 {
 152         struct kvmppc_spapr_tce_table *stt = NULL;
 153         unsigned long npages, size;
 154         int ret = -ENOMEM;
 155         int i;
 156
 157         if (!args->size)
 158                 return -EINVAL;
 159
 160         /* Check this LIOBN hasn't been previously allocated */
 161         list_for_each_entry(stt, &kvm->arch.spapr_tce_tables, list) {
 162                 if (stt->liobn == args->liobn)
 163                         return -EBUSY;
 164         }
 165
 166         size = args->size;
 167         npages = kvmppc_tce_pages(size);
 168         ret = kvmppc_account_memlimit(kvmppc_stt_pages(npages), true);
 169         if (ret) {
 170                 stt = NULL;
 171                 goto fail;
 172         }
 173
 174         stt = kzalloc(sizeof(*stt) + npages * sizeof(struct page *),
 175                       GFP_KERNEL);
 176         if (!stt)
 177                 goto fail;
 178
 179         stt->liobn = args->liobn;
 180         stt->page_shift = args->page_shift;
 181         stt->offset = args->offset;
 182         stt->size = size;
 183         stt->kvm = kvm;
 184
 185         for (i = 0; i < npages; i++) {
 186                 stt->pages[i] = alloc_page(GFP_KERNEL | __GFP_ZERO);
 187                 if (!stt->pages[i])
 188                         goto fail;
 189         }
 190
 191         kvm_get_kvm(kvm);
 192
 193         mutex_lock(&kvm->lock);
 194         list_add_rcu(&stt->list, &kvm->arch.spapr_tce_tables);
 195
 196         mutex_unlock(&kvm->lock);
 197
 198         return anon_inode_getfd("kvm-spapr-tce", &kvm_spapr_tce_fops,
 199                                 stt, O_RDWR | O_CLOEXEC);
 200
 201 fail:
 202         if (stt) {
 203                 for (i = 0; i < npages; i++)
 204                         if (stt->pages[i])
 205                                 __free_page(stt->pages[i]);
 206
 207                 kfree(stt);
 208         }
 209         return ret;
 210 }
 211
 212 long kvmppc_h_put_tce(struct kvm_vcpu *vcpu, unsigned long liobn,
 213                       unsigned long ioba, unsigned long tce)
 214 {
 215         struct kvmppc_spapr_tce_table *stt = kvmppc_find_table(vcpu, liobn);
 216         long ret;
 217
 218         /* udbg_printf("H_PUT_TCE(): liobn=0x%lx ioba=0x%lx, tce=0x%lx\n", */
 219         /*          liobn, ioba, tce); */
 220
 221         if (!stt)
 222                 return H_TOO_HARD;
 223
 224         ret = kvmppc_ioba_validate(stt, ioba, 1);
 225         if (ret != H_SUCCESS)
 226                 return ret;
 227
 228         ret = kvmppc_tce_validate(stt, tce);
 229         if (ret != H_SUCCESS)
 230                 return ret;
 231
 232         kvmppc_tce_put(stt, ioba >> stt->page_shift, tce);
 233
 234         return H_SUCCESS;
 235 }
 236 EXPORT_SYMBOL_GPL(kvmppc_h_put_tce);
 237
 238 long kvmppc_h_put_tce_indirect(struct kvm_vcpu *vcpu,
 239                 unsigned long liobn, unsigned long ioba,
 240                 unsigned long tce_list, unsigned long npages)
 241 {
 242         struct kvmppc_spapr_tce_table *stt;
 243         long i, ret = H_SUCCESS, idx;
 244         unsigned long entry, ua = 0;
 245         u64 __user *tces, tce;
 246
 247         stt = kvmppc_find_table(vcpu, liobn);
 248         if (!stt)
 249                 return H_TOO_HARD;
 250
 251         entry = ioba >> stt->page_shift;
 252         /*
 253          * SPAPR spec says that the maximum size of the list is 512 TCEs
 254          * so the whole table fits in 4K page
 255          */
 256         if (npages > 512)
 257                 return H_PARAMETER;
 258
 259         if (tce_list & (SZ_4K - 1))
 260                 return H_PARAMETER;
 261
 262         ret = kvmppc_ioba_validate(stt, ioba, npages);
 263         if (ret != H_SUCCESS)
 264                 return ret;
 265
 266         idx = srcu_read_lock(&vcpu->kvm->srcu);
 267         if (kvmppc_gpa_to_ua(vcpu->kvm, tce_list, &ua, NULL)) {
 268                 ret = H_TOO_HARD;
 269                 goto unlock_exit;
 270         }
 271         tces = (u64 __user *) ua;
 272
 273         for (i = 0; i < npages; ++i) {
 274                 if (get_user(tce, tces + i)) {
 275                         ret = H_TOO_HARD;
 276                         goto unlock_exit;
 277                 }
 278                 tce = be64_to_cpu(tce);
 279
 280                 ret = kvmppc_tce_validate(stt, tce);
 281                 if (ret != H_SUCCESS)
 282                         goto unlock_exit;
 283
 284                 kvmppc_tce_put(stt, entry + i, tce);
 285         }
 286
 287 unlock_exit:
 288         srcu_read_unlock(&vcpu->kvm->srcu, idx);
 289
 290         return ret;
 291 }
 292 EXPORT_SYMBOL_GPL(kvmppc_h_put_tce_indirect);
 293
 294 long kvmppc_h_stuff_tce(struct kvm_vcpu *vcpu,
 295                 unsigned long liobn, unsigned long ioba,
 296                 unsigned long tce_value, unsigned long npages)
 297 {
 298         struct kvmppc_spapr_tce_table *stt;
 299         long i, ret;
 300
 301         stt = kvmppc_find_table(vcpu, liobn);
 302         if (!stt)
 303                 return H_TOO_HARD;
 304
 305         ret = kvmppc_ioba_validate(stt, ioba, npages);
 306         if (ret != H_SUCCESS)
 307                 return ret;
 308
 309         /* Check permission bits only to allow userspace poison TCE for debug */
 310         if (tce_value & (TCE_PCI_WRITE | TCE_PCI_READ))
 311                 return H_PARAMETER;
 312
 313         for (i = 0; i < npages; ++i, ioba += (1ULL << stt->page_shift))
 314                 kvmppc_tce_put(stt, ioba >> stt->page_shift, tce_value);
 315
 316         return H_SUCCESS;
 317 }
 318 EXPORT_SYMBOL_GPL(kvmppc_h_stuff_tce);