1 /******************************************************************************
4 * Interface to privileged domain-0 commands.
6 * Copyright (c) 2002-2004, K A Fraser, B Dragovic
9 #include <linux/kernel.h>
10 #include <linux/sched.h>
11 #include <linux/slab.h>
12 #include <linux/string.h>
13 #include <linux/errno.h>
15 #include <linux/mman.h>
16 #include <linux/uaccess.h>
17 #include <linux/swap.h>
18 #include <linux/highmem.h>
19 #include <linux/pagemap.h>
20 #include <linux/seq_file.h>
22 #include <asm/pgalloc.h>
23 #include <asm/pgtable.h>
25 #include <asm/xen/hypervisor.h>
26 #include <asm/xen/hypercall.h>
29 #include <xen/privcmd.h>
30 #include <xen/interface/xen.h>
31 #include <xen/features.h>
33 #include <xen/xen-ops.h>
35 #ifndef HAVE_ARCH_PRIVCMD_MMAP
36 static int privcmd_enforce_singleshot_mapping(struct vm_area_struct *vma);
39 static long privcmd_ioctl_hypercall(void __user *udata)
41 struct privcmd_hypercall hypercall;
44 if (copy_from_user(&hypercall, udata, sizeof(hypercall)))
47 ret = privcmd_call(hypercall.op,
48 hypercall.arg[0], hypercall.arg[1],
49 hypercall.arg[2], hypercall.arg[3],
55 static void free_page_list(struct list_head *pages)
59 list_for_each_entry_safe(p, n, pages, lru)
62 INIT_LIST_HEAD(pages);
66 * Given an array of items in userspace, return a list of pages
67 * containing the data. If copying fails, either because of memory
68 * allocation failure or a problem reading user memory, return an
69 * error code; its up to the caller to dispose of any partial list.
71 static int gather_array(struct list_head *pagelist,
72 unsigned nelem, size_t size,
83 pagedata = NULL; /* quiet, gcc */
85 if (pageidx > PAGE_SIZE-size) {
86 struct page *page = alloc_page(GFP_KERNEL);
92 pagedata = page_address(page);
94 list_add_tail(&page->lru, pagelist);
99 if (copy_from_user(pagedata + pageidx, data, size))
113 * Call function "fn" on each element of the array fragmented
114 * over a list of pages.
116 static int traverse_pages(unsigned nelem, size_t size,
117 struct list_head *pos,
118 int (*fn)(void *data, void *state),
125 BUG_ON(size > PAGE_SIZE);
128 pagedata = NULL; /* hush, gcc */
131 if (pageidx > PAGE_SIZE-size) {
134 page = list_entry(pos, struct page, lru);
135 pagedata = page_address(page);
139 ret = (*fn)(pagedata + pageidx, state);
148 struct mmap_mfn_state {
150 struct vm_area_struct *vma;
154 static int mmap_mfn_range(void *data, void *state)
156 struct privcmd_mmap_entry *msg = data;
157 struct mmap_mfn_state *st = state;
158 struct vm_area_struct *vma = st->vma;
161 /* Do not allow range to wrap the address space. */
162 if ((msg->npages > (LONG_MAX >> PAGE_SHIFT)) ||
163 ((unsigned long)(msg->npages << PAGE_SHIFT) >= -st->va))
166 /* Range chunks must be contiguous in va space. */
167 if ((msg->va != st->va) ||
168 ((msg->va+(msg->npages<<PAGE_SHIFT)) > vma->vm_end))
171 rc = xen_remap_domain_mfn_range(vma,
173 msg->mfn, msg->npages,
179 st->va += msg->npages << PAGE_SHIFT;
184 static long privcmd_ioctl_mmap(void __user *udata)
186 struct privcmd_mmap mmapcmd;
187 struct mm_struct *mm = current->mm;
188 struct vm_area_struct *vma;
191 struct mmap_mfn_state state;
193 if (!xen_initial_domain())
196 if (copy_from_user(&mmapcmd, udata, sizeof(mmapcmd)))
199 rc = gather_array(&pagelist,
200 mmapcmd.num, sizeof(struct privcmd_mmap_entry),
203 if (rc || list_empty(&pagelist))
206 down_write(&mm->mmap_sem);
209 struct page *page = list_first_entry(&pagelist,
211 struct privcmd_mmap_entry *msg = page_address(page);
213 vma = find_vma(mm, msg->va);
216 if (!vma || (msg->va != vma->vm_start) ||
217 !privcmd_enforce_singleshot_mapping(vma))
221 state.va = vma->vm_start;
223 state.domain = mmapcmd.dom;
225 rc = traverse_pages(mmapcmd.num, sizeof(struct privcmd_mmap_entry),
227 mmap_mfn_range, &state);
231 up_write(&mm->mmap_sem);
234 free_page_list(&pagelist);
239 struct mmap_batch_state {
242 struct vm_area_struct *vma;
245 xen_pfn_t __user *user;
248 static int mmap_batch_fn(void *data, void *state)
250 xen_pfn_t *mfnp = data;
251 struct mmap_batch_state *st = state;
253 if (xen_remap_domain_mfn_range(st->vma, st->va & PAGE_MASK, *mfnp, 1,
254 st->vma->vm_page_prot, st->domain) < 0) {
255 *mfnp |= 0xf0000000U;
263 static int mmap_return_errors(void *data, void *state)
265 xen_pfn_t *mfnp = data;
266 struct mmap_batch_state *st = state;
268 return put_user(*mfnp, st->user++);
271 static struct vm_operations_struct privcmd_vm_ops;
273 static long privcmd_ioctl_mmap_batch(void __user *udata)
276 struct privcmd_mmapbatch m;
277 struct mm_struct *mm = current->mm;
278 struct vm_area_struct *vma;
279 unsigned long nr_pages;
281 struct mmap_batch_state state;
283 if (!xen_initial_domain())
286 if (copy_from_user(&m, udata, sizeof(m)))
290 if ((m.num <= 0) || (nr_pages > (LONG_MAX >> PAGE_SHIFT)))
293 ret = gather_array(&pagelist, m.num, sizeof(xen_pfn_t),
296 if (ret || list_empty(&pagelist))
299 down_write(&mm->mmap_sem);
301 vma = find_vma(mm, m.addr);
304 vma->vm_ops != &privcmd_vm_ops ||
305 (m.addr != vma->vm_start) ||
306 ((m.addr + (nr_pages << PAGE_SHIFT)) != vma->vm_end) ||
307 !privcmd_enforce_singleshot_mapping(vma)) {
308 up_write(&mm->mmap_sem);
312 state.domain = m.dom;
317 ret = traverse_pages(m.num, sizeof(xen_pfn_t),
318 &pagelist, mmap_batch_fn, &state);
320 up_write(&mm->mmap_sem);
324 ret = traverse_pages(m.num, sizeof(xen_pfn_t),
326 mmap_return_errors, &state);
330 free_page_list(&pagelist);
335 static long privcmd_ioctl(struct file *file,
336 unsigned int cmd, unsigned long data)
339 void __user *udata = (void __user *) data;
342 case IOCTL_PRIVCMD_HYPERCALL:
343 ret = privcmd_ioctl_hypercall(udata);
346 case IOCTL_PRIVCMD_MMAP:
347 ret = privcmd_ioctl_mmap(udata);
350 case IOCTL_PRIVCMD_MMAPBATCH:
351 ret = privcmd_ioctl_mmap_batch(udata);
362 #ifndef HAVE_ARCH_PRIVCMD_MMAP
363 static int privcmd_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
365 printk(KERN_DEBUG "privcmd_fault: vma=%p %lx-%lx, pgoff=%lx, uv=%p\n",
366 vma, vma->vm_start, vma->vm_end,
367 vmf->pgoff, vmf->virtual_address);
369 return VM_FAULT_SIGBUS;
372 static struct vm_operations_struct privcmd_vm_ops = {
373 .fault = privcmd_fault
376 static int privcmd_mmap(struct file *file, struct vm_area_struct *vma)
378 /* Unsupported for auto-translate guests. */
379 if (xen_feature(XENFEAT_auto_translated_physmap))
382 /* DONTCOPY is essential for Xen because copy_page_range doesn't know
383 * how to recreate these mappings */
384 vma->vm_flags |= VM_RESERVED | VM_IO | VM_DONTCOPY | VM_PFNMAP;
385 vma->vm_ops = &privcmd_vm_ops;
386 vma->vm_private_data = NULL;
391 static int privcmd_enforce_singleshot_mapping(struct vm_area_struct *vma)
393 return (xchg(&vma->vm_private_data, (void *)1) == NULL);
397 const struct file_operations privcmd_file_ops = {
398 .unlocked_ioctl = privcmd_ioctl,
399 .mmap = privcmd_mmap,