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 int kvm_iommu_map_pages(struct kvm *kvm, struct kvm_memory_slot *slot)
  36 {
  37         gfn_t gfn = slot->base_gfn;
  38         unsigned long npages = slot->npages;
  39         pfn_t pfn;
  40         int i, r = 0;
  41         struct iommu_domain *domain = kvm->arch.iommu_domain;
  42         int flags;
  43
  44         /* check if iommu exists and in use */
  45         if (!domain)
  46                 return 0;
  47
  48         flags = IOMMU_READ | IOMMU_WRITE;
  49         if (kvm->arch.iommu_flags & KVM_IOMMU_CACHE_COHERENCY)
  50                 flags |= IOMMU_CACHE;
  51
  52         for (i = 0; i < npages; i++) {
  53                 /* check if already mapped */
  54                 if (iommu_iova_to_phys(domain, gfn_to_gpa(gfn)))
  55                         continue;
  56
  57                 pfn = gfn_to_pfn_memslot(kvm, slot, gfn);
  58                 r = iommu_map_range(domain,
  59                                     gfn_to_gpa(gfn),
  60                                     pfn_to_hpa(pfn),
  61                                     PAGE_SIZE, flags);
  62                 if (r) {
  63                         printk(KERN_ERR "kvm_iommu_map_address:"
  64                                "iommu failed to map pfn=%lx\n", pfn);
  65                         goto unmap_pages;
  66                 }
  67                 gfn++;
  68         }
  69         return 0;
  70
  71 unmap_pages:
  72         kvm_iommu_put_pages(kvm, slot->base_gfn, i);
  73         return r;
  74 }
  75
  76 static int kvm_iommu_map_memslots(struct kvm *kvm)
  77 {
  78         int i, r = 0;
  79         struct kvm_memslots *slots;
  80
  81         slots = rcu_dereference(kvm->memslots);
  82
  83         for (i = 0; i < slots->nmemslots; i++) {
  84                 r = kvm_iommu_map_pages(kvm, &slots->memslots[i]);
  85                 if (r)
  86                         break;
  87         }
  88
  89         return r;
  90 }
  91
  92 int kvm_assign_device(struct kvm *kvm,
  93                       struct kvm_assigned_dev_kernel *assigned_dev)
  94 {
  95         struct pci_dev *pdev = NULL;
  96         struct iommu_domain *domain = kvm->arch.iommu_domain;
  97         int r, last_flags;
  98
  99         /* check if iommu exists and in use */
 100         if (!domain)
 101                 return 0;
 102
 103         pdev = assigned_dev->dev;
 104         if (pdev == NULL)
 105                 return -ENODEV;
 106
 107         r = iommu_attach_device(domain, &pdev->dev);
 108         if (r) {
 109                 printk(KERN_ERR "assign device %x:%x:%x.%x failed",
 110                         pci_domain_nr(pdev->bus),
 111                         pdev->bus->number,
 112                         PCI_SLOT(pdev->devfn),
 113                         PCI_FUNC(pdev->devfn));
 114                 return r;
 115         }
 116
 117         last_flags = kvm->arch.iommu_flags;
 118         if (iommu_domain_has_cap(kvm->arch.iommu_domain,
 119                                  IOMMU_CAP_CACHE_COHERENCY))
 120                 kvm->arch.iommu_flags |= KVM_IOMMU_CACHE_COHERENCY;
 121
 122         /* Check if need to update IOMMU page table for guest memory */
 123         if ((last_flags ^ kvm->arch.iommu_flags) ==
 124                         KVM_IOMMU_CACHE_COHERENCY) {
 125                 kvm_iommu_unmap_memslots(kvm);
 126                 r = kvm_iommu_map_memslots(kvm);
 127                 if (r)
 128                         goto out_unmap;
 129         }
 130
 131         printk(KERN_DEBUG "assign device %x:%x:%x.%x\n",
 132                 assigned_dev->host_segnr,
 133                 assigned_dev->host_busnr,
 134                 PCI_SLOT(assigned_dev->host_devfn),
 135                 PCI_FUNC(assigned_dev->host_devfn));
 136
 137         return 0;
 138 out_unmap:
 139         kvm_iommu_unmap_memslots(kvm);
 140         return r;
 141 }
 142
 143 int kvm_deassign_device(struct kvm *kvm,
 144                         struct kvm_assigned_dev_kernel *assigned_dev)
 145 {
 146         struct iommu_domain *domain = kvm->arch.iommu_domain;
 147         struct pci_dev *pdev = NULL;
 148
 149         /* check if iommu exists and in use */
 150         if (!domain)
 151                 return 0;
 152
 153         pdev = assigned_dev->dev;
 154         if (pdev == NULL)
 155                 return -ENODEV;
 156
 157         iommu_detach_device(domain, &pdev->dev);
 158
 159         printk(KERN_DEBUG "deassign device %x:%x:%x.%x\n",
 160                 assigned_dev->host_segnr,
 161                 assigned_dev->host_busnr,
 162                 PCI_SLOT(assigned_dev->host_devfn),
 163                 PCI_FUNC(assigned_dev->host_devfn));
 164
 165         return 0;
 166 }
 167
 168 int kvm_iommu_map_guest(struct kvm *kvm)
 169 {
 170         int r;
 171
 172         if (!iommu_found()) {
 173                 printk(KERN_ERR "%s: iommu not found\n", __func__);
 174                 return -ENODEV;
 175         }
 176
 177         kvm->arch.iommu_domain = iommu_domain_alloc();
 178         if (!kvm->arch.iommu_domain)
 179                 return -ENOMEM;
 180
 181         r = kvm_iommu_map_memslots(kvm);
 182         if (r)
 183                 goto out_unmap;
 184
 185         return 0;
 186
 187 out_unmap:
 188         kvm_iommu_unmap_memslots(kvm);
 189         return r;
 190 }
 191
 192 static void kvm_iommu_put_pages(struct kvm *kvm,
 193                                 gfn_t base_gfn, unsigned long npages)
 194 {
 195         gfn_t gfn = base_gfn;
 196         pfn_t pfn;
 197         struct iommu_domain *domain = kvm->arch.iommu_domain;
 198         unsigned long i;
 199         u64 phys;
 200
 201         /* check if iommu exists and in use */
 202         if (!domain)
 203                 return;
 204
 205         for (i = 0; i < npages; i++) {
 206                 phys = iommu_iova_to_phys(domain, gfn_to_gpa(gfn));
 207                 pfn = phys >> PAGE_SHIFT;
 208                 kvm_release_pfn_clean(pfn);
 209                 gfn++;
 210         }
 211
 212         iommu_unmap_range(domain, gfn_to_gpa(base_gfn), PAGE_SIZE * npages);
 213 }
 214
 215 static int kvm_iommu_unmap_memslots(struct kvm *kvm)
 216 {
 217         int i;
 218         struct kvm_memslots *slots;
 219
 220         slots = rcu_dereference(kvm->memslots);
 221
 222         for (i = 0; i < slots->nmemslots; i++) {
 223                 kvm_iommu_put_pages(kvm, slots->memslots[i].base_gfn,
 224                                     slots->memslots[i].npages);
 225         }
 226
 227         return 0;
 228 }
 229
 230 int kvm_iommu_unmap_guest(struct kvm *kvm)
 231 {
 232         struct iommu_domain *domain = kvm->arch.iommu_domain;
 233
 234         /* check if iommu exists and in use */
 235         if (!domain)
 236                 return 0;
 237
 238         kvm_iommu_unmap_memslots(kvm);
 239         iommu_domain_free(domain);
 240         return 0;
 241 }