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 kvmppc_spapr_tce_table *stt)
  49 {
  50         struct kvm *kvm = stt->kvm;
  51         int i;
  52
  53         mutex_lock(&kvm->lock);
  54         list_del(&stt->list);
  55         for (i = 0; i < kvmppc_stt_npages(stt->window_size); i++)
  56                 __free_page(stt->pages[i]);
  57         kfree(stt);
  58         mutex_unlock(&kvm->lock);
  59
  60         kvm_put_kvm(kvm);
  61 }
  62
  63 static int kvm_spapr_tce_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
  64 {
  65         struct kvmppc_spapr_tce_table *stt = vma->vm_file->private_data;
  66         struct page *page;
  67
  68         if (vmf->pgoff >= kvmppc_stt_npages(stt->window_size))
  69                 return VM_FAULT_SIGBUS;
  70
  71         page = stt->pages[vmf->pgoff];
  72         get_page(page);
  73         vmf->page = page;
  74         return 0;
  75 }
  76
  77 static const struct vm_operations_struct kvm_spapr_tce_vm_ops = {
  78         .fault = kvm_spapr_tce_fault,
  79 };
  80
  81 static int kvm_spapr_tce_mmap(struct file *file, struct vm_area_struct *vma)
  82 {
  83         vma->vm_ops = &kvm_spapr_tce_vm_ops;
  84         return 0;
  85 }
  86
  87 static int kvm_spapr_tce_release(struct inode *inode, struct file *filp)
  88 {
  89         struct kvmppc_spapr_tce_table *stt = filp->private_data;
  90
  91         release_spapr_tce_table(stt);
  92         return 0;
  93 }
  94
  95 static const struct file_operations kvm_spapr_tce_fops = {
  96         .mmap           = kvm_spapr_tce_mmap,
  97         .release        = kvm_spapr_tce_release,
  98 };
  99
 100 long kvm_vm_ioctl_create_spapr_tce(struct kvm *kvm,
 101                                    struct kvm_create_spapr_tce *args)
 102 {
 103         struct kvmppc_spapr_tce_table *stt = NULL;
 104         long npages;
 105         int ret = -ENOMEM;
 106         int i;
 107
 108         /* Check this LIOBN hasn't been previously allocated */
 109         list_for_each_entry(stt, &kvm->arch.spapr_tce_tables, list) {
 110                 if (stt->liobn == args->liobn)
 111                         return -EBUSY;
 112         }
 113
 114         npages = kvmppc_stt_npages(args->window_size);
 115
 116         stt = kzalloc(sizeof(*stt) + npages * sizeof(struct page *),
 117                       GFP_KERNEL);
 118         if (!stt)
 119                 goto fail;
 120
 121         stt->liobn = args->liobn;
 122         stt->window_size = args->window_size;
 123         stt->kvm = kvm;
 124
 125         for (i = 0; i < npages; i++) {
 126                 stt->pages[i] = alloc_page(GFP_KERNEL | __GFP_ZERO);
 127                 if (!stt->pages[i])
 128                         goto fail;
 129         }
 130
 131         kvm_get_kvm(kvm);
 132
 133         mutex_lock(&kvm->lock);
 134         list_add(&stt->list, &kvm->arch.spapr_tce_tables);
 135
 136         mutex_unlock(&kvm->lock);
 137
 138         return anon_inode_getfd("kvm-spapr-tce", &kvm_spapr_tce_fops,
 139                                 stt, O_RDWR | O_CLOEXEC);
 140
 141 fail:
 142         if (stt) {
 143                 for (i = 0; i < npages; i++)
 144                         if (stt->pages[i])
 145                                 __free_page(stt->pages[i]);
 146
 147                 kfree(stt);
 148         }
 149         return ret;
 150 }