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
kvmppc_stt_npages(unsigned long window_size)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
release_spapr_tce_table(struct kvmppc_spapr_tce_table * stt)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
kvm_spapr_tce_fault(struct vm_area_struct * vma,struct vm_fault * vmf)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
kvm_spapr_tce_mmap(struct file * file,struct vm_area_struct * vma)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
kvm_spapr_tce_release(struct inode * inode,struct file * filp)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
kvm_vm_ioctl_create_spapr_tce(struct kvm * kvm,struct kvm_create_spapr_tce * args)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 struct kvmppc_spapr_tce_table *siter;
105 long npages;
106 int ret = -ENOMEM;
107 int i;
108
109 npages = kvmppc_stt_npages(args->window_size);
110
111 stt = kzalloc(sizeof(*stt) + npages * sizeof(struct page *),
112 GFP_KERNEL);
113 if (!stt)
114 return ret;
115
116 stt->liobn = args->liobn;
117 stt->window_size = args->window_size;
118 stt->kvm = kvm;
119
120 for (i = 0; i < npages; i++) {
121 stt->pages[i] = alloc_page(GFP_KERNEL | __GFP_ZERO);
122 if (!stt->pages[i])
123 goto fail;
124 }
125
126 mutex_lock(&kvm->lock);
127
128 /* Check this LIOBN hasn't been previously allocated */
129 ret = 0;
130 list_for_each_entry(siter, &kvm->arch.spapr_tce_tables, list) {
131 if (siter->liobn == args->liobn) {
132 ret = -EBUSY;
133 break;
134 }
135 }
136
137 if (!ret)
138 ret = anon_inode_getfd("kvm-spapr-tce", &kvm_spapr_tce_fops,
139 stt, O_RDWR | O_CLOEXEC);
140
141 if (ret >= 0) {
142 list_add(&stt->list, &kvm->arch.spapr_tce_tables);
143 kvm_get_kvm(kvm);
144 }
145
146 mutex_unlock(&kvm->lock);
147
148 if (ret >= 0)
149 return ret;
150
151 fail:
152 for (i = 0; i < npages; i++)
153 if (stt->pages[i])
154 __free_page(stt->pages[i]);
155
156 kfree(stt);
157 return ret;
158 }
159