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/mmu-hash64.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 window_size)
  44 {
  45         return ALIGN((window_size >> IOMMU_PAGE_SHIFT_4K)
  46                      * 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         int i;
  99         unsigned long npages = kvmppc_tce_pages(stt->window_size);
 100
 101         for (i = 0; i < npages; i++)
 102                 __free_page(stt->pages[i]);
 103
 104         kfree(stt);
 105 }
 106
 107 static int kvm_spapr_tce_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 108 {
 109         struct kvmppc_spapr_tce_table *stt = vma->vm_file->private_data;
 110         struct page *page;
 111
 112         if (vmf->pgoff >= kvmppc_tce_pages(stt->window_size))
 113                 return VM_FAULT_SIGBUS;
 114
 115         page = stt->pages[vmf->pgoff];
 116         get_page(page);
 117         vmf->page = page;
 118         return 0;
 119 }
 120
 121 static const struct vm_operations_struct kvm_spapr_tce_vm_ops = {
 122         .fault = kvm_spapr_tce_fault,
 123 };
 124
 125 static int kvm_spapr_tce_mmap(struct file *file, struct vm_area_struct *vma)
 126 {
 127         vma->vm_ops = &kvm_spapr_tce_vm_ops;
 128         return 0;
 129 }
 130
 131 static int kvm_spapr_tce_release(struct inode *inode, struct file *filp)
 132 {
 133         struct kvmppc_spapr_tce_table *stt = filp->private_data;
 134
 135         list_del_rcu(&stt->list);
 136
 137         kvm_put_kvm(stt->kvm);
 138
 139         kvmppc_account_memlimit(
 140                 kvmppc_stt_pages(kvmppc_tce_pages(stt->window_size)), false);
 141         call_rcu(&stt->rcu, release_spapr_tce_table);
 142
 143         return 0;
 144 }
 145
 146 static const struct file_operations kvm_spapr_tce_fops = {
 147         .mmap           = kvm_spapr_tce_mmap,
 148         .release        = kvm_spapr_tce_release,
 149 };
 150
 151 long kvm_vm_ioctl_create_spapr_tce(struct kvm *kvm,
 152                                    struct kvm_create_spapr_tce *args)
 153 {
 154         struct kvmppc_spapr_tce_table *stt = NULL;
 155         unsigned long npages;
 156         int ret = -ENOMEM;
 157         int i;
 158
 159         /* Check this LIOBN hasn't been previously allocated */
 160         list_for_each_entry(stt, &kvm->arch.spapr_tce_tables, list) {
 161                 if (stt->liobn == args->liobn)
 162                         return -EBUSY;
 163         }
 164
 165         npages = kvmppc_tce_pages(args->window_size);
 166         ret = kvmppc_account_memlimit(kvmppc_stt_pages(npages), true);
 167         if (ret) {
 168                 stt = NULL;
 169                 goto fail;
 170         }
 171
 172         stt = kzalloc(sizeof(*stt) + npages * sizeof(struct page *),
 173                       GFP_KERNEL);
 174         if (!stt)
 175                 goto fail;
 176
 177         stt->liobn = args->liobn;
 178         stt->window_size = args->window_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         kvm_get_kvm(kvm);
 188
 189         mutex_lock(&kvm->lock);
 190         list_add_rcu(&stt->list, &kvm->arch.spapr_tce_tables);
 191
 192         mutex_unlock(&kvm->lock);
 193
 194         return anon_inode_getfd("kvm-spapr-tce", &kvm_spapr_tce_fops,
 195                                 stt, O_RDWR | O_CLOEXEC);
 196
 197 fail:
 198         if (stt) {
 199                 for (i = 0; i < npages; i++)
 200                         if (stt->pages[i])
 201                                 __free_page(stt->pages[i]);
 202
 203                 kfree(stt);
 204         }
 205         return ret;
 206 }
 207
 208 long kvmppc_h_put_tce_indirect(struct kvm_vcpu *vcpu,
 209                 unsigned long liobn, unsigned long ioba,
 210                 unsigned long tce_list, unsigned long npages)
 211 {
 212         struct kvmppc_spapr_tce_table *stt;
 213         long i, ret = H_SUCCESS, idx;
 214         unsigned long entry, ua = 0;
 215         u64 __user *tces, tce;
 216
 217         stt = kvmppc_find_table(vcpu, liobn);
 218         if (!stt)
 219                 return H_TOO_HARD;
 220
 221         entry = ioba >> IOMMU_PAGE_SHIFT_4K;
 222         /*
 223          * SPAPR spec says that the maximum size of the list is 512 TCEs
 224          * so the whole table fits in 4K page
 225          */
 226         if (npages > 512)
 227                 return H_PARAMETER;
 228
 229         if (tce_list & (SZ_4K - 1))
 230                 return H_PARAMETER;
 231
 232         ret = kvmppc_ioba_validate(stt, ioba, npages);
 233         if (ret != H_SUCCESS)
 234                 return ret;
 235
 236         idx = srcu_read_lock(&vcpu->kvm->srcu);
 237         if (kvmppc_gpa_to_ua(vcpu->kvm, tce_list, &ua, NULL)) {
 238                 ret = H_TOO_HARD;
 239                 goto unlock_exit;
 240         }
 241         tces = (u64 __user *) ua;
 242
 243         for (i = 0; i < npages; ++i) {
 244                 if (get_user(tce, tces + i)) {
 245                         ret = H_TOO_HARD;
 246                         goto unlock_exit;
 247                 }
 248                 tce = be64_to_cpu(tce);
 249
 250                 ret = kvmppc_tce_validate(stt, tce);
 251                 if (ret != H_SUCCESS)
 252                         goto unlock_exit;
 253
 254                 kvmppc_tce_put(stt, entry + i, tce);
 255         }
 256
 257 unlock_exit:
 258         srcu_read_unlock(&vcpu->kvm->srcu, idx);
 259
 260         return ret;
 261 }
 262 EXPORT_SYMBOL_GPL(kvmppc_h_put_tce_indirect);