LXR linux/arch/powerpc/kvm/book3s_64

   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
  42static 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
  48static 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
  63static 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
  77static const struct vm_operations_struct kvm_spapr_tce_vm_ops = {
  78        .fault = kvm_spapr_tce_fault,
  79};
  80
  81static 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
  87static 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
  95static const struct file_operations kvm_spapr_tce_fops = {
  96        .mmap           = kvm_spapr_tce_mmap,
  97        .release        = kvm_spapr_tce_release,
  98};
  99
 100long 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);
 140
 141fail:
 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}
 151