virt/kvm/iommu.c

   1 /*
   2  * Copyright (c) 2006, Intel Corporation.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms and conditions of the GNU General Public License,
   6  * version 2, as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  15  * Place - Suite 330, Boston, MA 02111-1307 USA.
  16  *
  17  * Copyright (C) 2006-2008 Intel Corporation
  18  * Copyright IBM Corporation, 2008
  19  * Author: Allen M. Kay <allen.m.kay@intel.com>
  20  * Author: Weidong Han <weidong.han@intel.com>
  21  * Author: Ben-Ami Yassour <benami@il.ibm.com>
  22  */
  23
  24 #include <linux/list.h>
  25 #include <linux/kvm_host.h>
  26 #include <linux/pci.h>
  27 #include <linux/dmar.h>
  28 #include <linux/iommu.h>
  29 #include <linux/intel-iommu.h>
  30
  31 static int kvm_iommu_unmap_memslots(struct kvm *kvm);
  32 static void kvm_iommu_put_pages(struct kvm *kvm,
  33                                 gfn_t base_gfn, unsigned long npages);
  34
  35 static pfn_t kvm_pin_pages(struct kvm *kvm, struct kvm_memory_slot *slot,
  36                            gfn_t gfn, unsigned long size)
  37 {
  38         gfn_t end_gfn;
  39         pfn_t pfn;
  40
  41         pfn     = gfn_to_pfn_memslot(kvm, slot, gfn);
  42         end_gfn = gfn + (size >> PAGE_SHIFT);
  43         gfn    += 1;
  44
  45         if (is_error_pfn(pfn))
  46                 return pfn;
  47
  48         while (gfn < end_gfn)
  49                 gfn_to_pfn_memslot(kvm, slot, gfn++);
  50
  51         return pfn;
  52 }
  53
  54 int kvm_iommu_map_pages(struct kvm *kvm, struct kvm_memory_slot *slot)
  55 {
  56         gfn_t gfn, end_gfn;
  57         pfn_t pfn;
  58         int r = 0;
  59         struct iommu_domain *domain = kvm->arch.iommu_domain;
  60         int flags;
  61
  62         /* check if iommu exists and in use */
  63         if (!domain)
  64                 return 0;
  65
  66         gfn     = slot->base_gfn;
  67         end_gfn = gfn + slot->npages;
  68
  69         flags = IOMMU_READ | IOMMU_WRITE;
  70         if (kvm->arch.iommu_flags & KVM_IOMMU_CACHE_COHERENCY)
  71                 flags |= IOMMU_CACHE;
  72
  73
  74         while (gfn < end_gfn) {
  75                 unsigned long page_size;
  76
  77                 /* Check if already mapped */
  78                 if (iommu_iova_to_phys(domain, gfn_to_gpa(gfn))) {
  79                         gfn += 1;
  80                         continue;
  81                 }
  82
  83                 /* Get the page size we could use to map */
  84                 page_size = kvm_host_page_size(kvm, gfn);
  85
  86                 /* Make sure the page_size does not exceed the memslot */
  87                 while ((gfn + (page_size >> PAGE_SHIFT)) > end_gfn)
  88                         page_size >>= 1;
  89
  90                 /* Make sure gfn is aligned to the page size we want to map */
  91                 while ((gfn << PAGE_SHIFT) & (page_size - 1))
  92                         page_size >>= 1;
  93
  94                 /*
  95                  * Pin all pages we are about to map in memory. This is
  96                  * important because we unmap and unpin in 4kb steps later.
  97                  */
  98                 pfn = kvm_pin_pages(kvm, slot, gfn, page_size);
  99                 if (is_error_pfn(pfn)) {
 100                         gfn += 1;
 101                         continue;
 102                 }
 103
 104                 /* Map into IO address space */
 105                 r = iommu_map(domain, gfn_to_gpa(gfn), pfn_to_hpa(pfn),
 106                               get_order(page_size), flags);
 107                 if (r) {
 108                         printk(KERN_ERR "kvm_iommu_map_address:"
 109                                "iommu failed to map pfn=%lx\n", pfn);
 110                         goto unmap_pages;
 111                 }
 112
 113                 gfn += page_size >> PAGE_SHIFT;
 114
 115
 116         }
 117
 118         return 0;
 119
 120 unmap_pages:
 121         kvm_iommu_put_pages(kvm, slot->base_gfn, gfn);
 122         return r;
 123 }
 124
 125 static int kvm_iommu_map_memslots(struct kvm *kvm)
 126 {
 127         int i, r = 0;
 128         struct kvm_memslots *slots;
 129
 130         slots = kvm_memslots(kvm);
 131
 132         for (i = 0; i < slots->nmemslots; i++) {
 133                 r = kvm_iommu_map_pages(kvm, &slots->memslots[i]);
 134                 if (r)
 135                         break;
 136         }
 137
 138         return r;
 139 }
 140
 141 int kvm_assign_device(struct kvm *kvm,
 142                       struct kvm_assigned_dev_kernel *assigned_dev)
 143 {
 144         struct pci_dev *pdev = NULL;
 145         struct iommu_domain *domain = kvm->arch.iommu_domain;
 146         int r, last_flags;
 147
 148         /* check if iommu exists and in use */
 149         if (!domain)
 150                 return 0;
 151
 152         pdev = assigned_dev->dev;
 153         if (pdev == NULL)
 154                 return -ENODEV;
 155
 156         r = iommu_attach_device(domain, &pdev->dev);
 157         if (r) {
 158                 printk(KERN_ERR "assign device %x:%x:%x.%x failed",
 159                         pci_domain_nr(pdev->bus),
 160                         pdev->bus->number,
 161                         PCI_SLOT(pdev->devfn),
 162                         PCI_FUNC(pdev->devfn));
 163                 return r;
 164         }
 165
 166         last_flags = kvm->arch.iommu_flags;
 167         if (iommu_domain_has_cap(kvm->arch.iommu_domain,
 168                                  IOMMU_CAP_CACHE_COHERENCY))
 169                 kvm->arch.iommu_flags |= KVM_IOMMU_CACHE_COHERENCY;
 170
 171         /* Check if need to update IOMMU page table for guest memory */
 172         if ((last_flags ^ kvm->arch.iommu_flags) ==
 173                         KVM_IOMMU_CACHE_COHERENCY) {
 174                 kvm_iommu_unmap_memslots(kvm);
 175                 r = kvm_iommu_map_memslots(kvm);
 176                 if (r)
 177                         goto out_unmap;
 178         }
 179
 180         printk(KERN_DEBUG "assign device %x:%x:%x.%x\n",
 181                 assigned_dev->host_segnr,
 182                 assigned_dev->host_busnr,
 183                 PCI_SLOT(assigned_dev->host_devfn),
 184                 PCI_FUNC(assigned_dev->host_devfn));
 185
 186         return 0;
 187 out_unmap:
 188         kvm_iommu_unmap_memslots(kvm);
 189         return r;
 190 }
 191
 192 int kvm_deassign_device(struct kvm *kvm,
 193                         struct kvm_assigned_dev_kernel *assigned_dev)
 194 {
 195         struct iommu_domain *domain = kvm->arch.iommu_domain;
 196         struct pci_dev *pdev = NULL;
 197
 198         /* check if iommu exists and in use */
 199         if (!domain)
 200                 return 0;
 201
 202         pdev = assigned_dev->dev;
 203         if (pdev == NULL)
 204                 return -ENODEV;
 205
 206         iommu_detach_device(domain, &pdev->dev);
 207
 208         printk(KERN_DEBUG "deassign device %x:%x:%x.%x\n",
 209                 assigned_dev->host_segnr,
 210                 assigned_dev->host_busnr,
 211                 PCI_SLOT(assigned_dev->host_devfn),
 212                 PCI_FUNC(assigned_dev->host_devfn));
 213
 214         return 0;
 215 }
 216
 217 int kvm_iommu_map_guest(struct kvm *kvm)
 218 {
 219         int r;
 220
 221         if (!iommu_found()) {
 222                 printk(KERN_ERR "%s: iommu not found\n", __func__);
 223                 return -ENODEV;
 224         }
 225
 226         kvm->arch.iommu_domain = iommu_domain_alloc();
 227         if (!kvm->arch.iommu_domain)
 228                 return -ENOMEM;
 229
 230         r = kvm_iommu_map_memslots(kvm);
 231         if (r)
 232                 goto out_unmap;
 233
 234         return 0;
 235
 236 out_unmap:
 237         kvm_iommu_unmap_memslots(kvm);
 238         return r;
 239 }
 240
 241 static void kvm_unpin_pages(struct kvm *kvm, pfn_t pfn, unsigned long npages)
 242 {
 243         unsigned long i;
 244
 245         for (i = 0; i < npages; ++i)
 246                 kvm_release_pfn_clean(pfn + i);
 247 }
 248
 249 static void kvm_iommu_put_pages(struct kvm *kvm,
 250                                 gfn_t base_gfn, unsigned long npages)
 251 {
 252         struct iommu_domain *domain;
 253         gfn_t end_gfn, gfn;
 254         pfn_t pfn;
 255         u64 phys;
 256
 257         domain  = kvm->arch.iommu_domain;
 258         end_gfn = base_gfn + npages;
 259         gfn     = base_gfn;
 260
 261         /* check if iommu exists and in use */
 262         if (!domain)
 263                 return;
 264
 265         while (gfn < end_gfn) {
 266                 unsigned long unmap_pages;
 267                 int order;
 268
 269                 /* Get physical address */
 270                 phys = iommu_iova_to_phys(domain, gfn_to_gpa(gfn));
 271                 pfn  = phys >> PAGE_SHIFT;
 272
 273                 /* Unmap address from IO address space */
 274                 order       = iommu_unmap(domain, gfn_to_gpa(gfn), PAGE_SIZE);
 275                 unmap_pages = 1ULL << order;
 276
 277                 /* Unpin all pages we just unmapped to not leak any memory */
 278                 kvm_unpin_pages(kvm, pfn, unmap_pages);
 279
 280                 gfn += unmap_pages;
 281         }
 282 }
 283
 284 static int kvm_iommu_unmap_memslots(struct kvm *kvm)
 285 {
 286         int i;
 287         struct kvm_memslots *slots;
 288
 289         slots = kvm_memslots(kvm);
 290
 291         for (i = 0; i < slots->nmemslots; i++) {
 292                 kvm_iommu_put_pages(kvm, slots->memslots[i].base_gfn,
 293                                     slots->memslots[i].npages);
 294         }
 295
 296         return 0;
 297 }
 298
 299 int kvm_iommu_unmap_guest(struct kvm *kvm)
 300 {
 301         struct iommu_domain *domain = kvm->arch.iommu_domain;
 302
 303         /* check if iommu exists and in use */
 304         if (!domain)
 305                 return 0;
 306
 307         kvm_iommu_unmap_memslots(kvm);
 308         iommu_domain_free(domain);
 309         return 0;
 310 }