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  */
  18
  19 #include <linux/types.h>
  20 #include <linux/string.h>
  21 #include <linux/kvm.h>
  22 #include <linux/kvm_host.h>
  23 #include <linux/highmem.h>
  24 #include <linux/gfp.h>
  25 #include <linux/slab.h>
  26 #include <linux/hugetlb.h>
  27 #include <linux/list.h>
  28 #include <linux/anon_inodes.h>
  29
  30 #include <asm/tlbflush.h>
  31 #include <asm/kvm_ppc.h>
  32 #include <asm/kvm_book3s.h>
  33 #include <asm/mmu-hash64.h>
  34 #include <asm/hvcall.h>
  35 #include <asm/synch.h>
  36 #include <asm/ppc-opcode.h>
  37 #include <asm/kvm_host.h>
  38 #include <asm/udbg.h>
  39
  40 #define TCES_PER_PAGE   (PAGE_SIZE / sizeof(u64))
  41
  42 static long kvmppc_stt_npages(unsigned long window_size)
  43 {
  44         return ALIGN((window_size >> SPAPR_TCE_SHIFT)
  45                      * sizeof(u64), PAGE_SIZE) / PAGE_SIZE;
  46 }
  47
  48 static void release_spapr_tce_table(struct rcu_head *head)
  49 {
  50         struct kvmppc_spapr_tce_table *stt = container_of(head,
  51                         struct kvmppc_spapr_tce_table, rcu);
  52         int i;
  53
  54         for (i = 0; i < kvmppc_stt_npages(stt->window_size); i++)
  55                 __free_page(stt->pages[i]);
  56
  57         kfree(stt);
  58 }
  59
  60 static int kvm_spapr_tce_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
  61 {
  62         struct kvmppc_spapr_tce_table *stt = vma->vm_file->private_data;
  63         struct page *page;
  64
  65         if (vmf->pgoff >= kvmppc_stt_npages(stt->window_size))
  66                 return VM_FAULT_SIGBUS;
  67
  68         page = stt->pages[vmf->pgoff];
  69         get_page(page);
  70         vmf->page = page;
  71         return 0;
  72 }
  73
  74 static const struct vm_operations_struct kvm_spapr_tce_vm_ops = {
  75         .fault = kvm_spapr_tce_fault,
  76 };
  77
  78 static int kvm_spapr_tce_mmap(struct file *file, struct vm_area_struct *vma)
  79 {
  80         vma->vm_ops = &kvm_spapr_tce_vm_ops;
  81         return 0;
  82 }
  83
  84 static int kvm_spapr_tce_release(struct inode *inode, struct file *filp)
  85 {
  86         struct kvmppc_spapr_tce_table *stt = filp->private_data;
  87
  88         list_del_rcu(&stt->list);
  89
  90         kvm_put_kvm(stt->kvm);
  91
  92         call_rcu(&stt->rcu, release_spapr_tce_table);
  93
  94         return 0;
  95 }
  96
  97 static const struct file_operations kvm_spapr_tce_fops = {
  98         .mmap           = kvm_spapr_tce_mmap,
  99         .release        = kvm_spapr_tce_release,
 100 };
 101
 102 long kvm_vm_ioctl_create_spapr_tce(struct kvm *kvm,
 103                                    struct kvm_create_spapr_tce *args)
 104 {
 105         struct kvmppc_spapr_tce_table *stt = NULL;
 106         long npages;
 107         int ret = -ENOMEM;
 108         int i;
 109
 110         /* Check this LIOBN hasn't been previously allocated */
 111         list_for_each_entry(stt, &kvm->arch.spapr_tce_tables, list) {
 112                 if (stt->liobn == args->liobn)
 113                         return -EBUSY;
 114         }
 115
 116         npages = kvmppc_stt_npages(args->window_size);
 117
 118         stt = kzalloc(sizeof(*stt) + npages * sizeof(struct page *),
 119                       GFP_KERNEL);
 120         if (!stt)
 121                 goto fail;
 122
 123         stt->liobn = args->liobn;
 124         stt->window_size = args->window_size;
 125         stt->kvm = kvm;
 126
 127         for (i = 0; i < npages; i++) {
 128                 stt->pages[i] = alloc_page(GFP_KERNEL | __GFP_ZERO);
 129                 if (!stt->pages[i])
 130                         goto fail;
 131         }
 132
 133         kvm_get_kvm(kvm);
 134
 135         mutex_lock(&kvm->lock);
 136         list_add_rcu(&stt->list, &kvm->arch.spapr_tce_tables);
 137
 138         mutex_unlock(&kvm->lock);
 139
 140         return anon_inode_getfd("kvm-spapr-tce", &kvm_spapr_tce_fops,
 141                                 stt, O_RDWR | O_CLOEXEC);
 142
 143 fail:
 144         if (stt) {
 145                 for (i = 0; i < npages; i++)
 146                         if (stt->pages[i])
 147                                 __free_page(stt->pages[i]);
 148
 149                 kfree(stt);
 150         }
 151         return ret;
 152 }