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authorMukesh Rathor <mukesh.rathor@oracle.com>2012-10-17 20:11:21 -0400
committerIan Campbell <ian.campbell@citrix.com>2012-11-29 07:57:52 -0500
commitd71f513985c22f1050295d1a7e4327cf9fb060da (patch)
tree3da00d6cad246972d2cfcd76a945b96efedcac80 /drivers/xen/privcmd.c
parent9a032e393a8bc888a9b0c898cbdb9db2cee7b536 (diff)
xen: privcmd: support autotranslated physmap guests.
PVH and ARM only support the batch interface. To map a foreign page to a process, the PFN must be allocated and the autotranslated path uses ballooning for that purpose. The returned PFN is then mapped to the foreign page. xen_unmap_domain_mfn_range() is introduced to unmap these pages via the privcmd close call. Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com> [v1: Fix up privcmd_close] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Ian Campbell <ian.campbell@citrix.com> [v2: used for ARM too]
Diffstat (limited to 'drivers/xen/privcmd.c')
-rw-r--r--drivers/xen/privcmd.c69
1 files changed, 67 insertions, 2 deletions
diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c
index b612267a8cb6..b9d08987a5a5 100644
--- a/drivers/xen/privcmd.c
+++ b/drivers/xen/privcmd.c
@@ -33,11 +33,14 @@
33#include <xen/features.h> 33#include <xen/features.h>
34#include <xen/page.h> 34#include <xen/page.h>
35#include <xen/xen-ops.h> 35#include <xen/xen-ops.h>
36#include <xen/balloon.h>
36 37
37#include "privcmd.h" 38#include "privcmd.h"
38 39
39MODULE_LICENSE("GPL"); 40MODULE_LICENSE("GPL");
40 41
42#define PRIV_VMA_LOCKED ((void *)1)
43
41#ifndef HAVE_ARCH_PRIVCMD_MMAP 44#ifndef HAVE_ARCH_PRIVCMD_MMAP
42static int privcmd_enforce_singleshot_mapping(struct vm_area_struct *vma); 45static int privcmd_enforce_singleshot_mapping(struct vm_area_struct *vma);
43#endif 46#endif
@@ -199,6 +202,10 @@ static long privcmd_ioctl_mmap(void __user *udata)
199 if (!xen_initial_domain()) 202 if (!xen_initial_domain())
200 return -EPERM; 203 return -EPERM;
201 204
205 /* We only support privcmd_ioctl_mmap_batch for auto translated. */
206 if (xen_feature(XENFEAT_auto_translated_physmap))
207 return -ENOSYS;
208
202 if (copy_from_user(&mmapcmd, udata, sizeof(mmapcmd))) 209 if (copy_from_user(&mmapcmd, udata, sizeof(mmapcmd)))
203 return -EFAULT; 210 return -EFAULT;
204 211
@@ -246,6 +253,7 @@ struct mmap_batch_state {
246 domid_t domain; 253 domid_t domain;
247 unsigned long va; 254 unsigned long va;
248 struct vm_area_struct *vma; 255 struct vm_area_struct *vma;
256 int index;
249 /* A tristate: 257 /* A tristate:
250 * 0 for no errors 258 * 0 for no errors
251 * 1 if at least one error has happened (and no 259 * 1 if at least one error has happened (and no
@@ -260,15 +268,24 @@ struct mmap_batch_state {
260 xen_pfn_t __user *user_mfn; 268 xen_pfn_t __user *user_mfn;
261}; 269};
262 270
271/* auto translated dom0 note: if domU being created is PV, then mfn is
272 * mfn(addr on bus). If it's auto xlated, then mfn is pfn (input to HAP).
273 */
263static int mmap_batch_fn(void *data, void *state) 274static int mmap_batch_fn(void *data, void *state)
264{ 275{
265 xen_pfn_t *mfnp = data; 276 xen_pfn_t *mfnp = data;
266 struct mmap_batch_state *st = state; 277 struct mmap_batch_state *st = state;
278 struct vm_area_struct *vma = st->vma;
279 struct page **pages = vma->vm_private_data;
280 struct page *cur_page = NULL;
267 int ret; 281 int ret;
268 282
283 if (xen_feature(XENFEAT_auto_translated_physmap))
284 cur_page = pages[st->index++];
285
269 ret = xen_remap_domain_mfn_range(st->vma, st->va & PAGE_MASK, *mfnp, 1, 286 ret = xen_remap_domain_mfn_range(st->vma, st->va & PAGE_MASK, *mfnp, 1,
270 st->vma->vm_page_prot, st->domain, 287 st->vma->vm_page_prot, st->domain,
271 NULL); 288 &cur_page);
272 289
273 /* Store error code for second pass. */ 290 /* Store error code for second pass. */
274 *(st->err++) = ret; 291 *(st->err++) = ret;
@@ -304,6 +321,32 @@ static int mmap_return_errors_v1(void *data, void *state)
304 return __put_user(*mfnp, st->user_mfn++); 321 return __put_user(*mfnp, st->user_mfn++);
305} 322}
306 323
324/* Allocate pfns that are then mapped with gmfns from foreign domid. Update
325 * the vma with the page info to use later.
326 * Returns: 0 if success, otherwise -errno
327 */
328static int alloc_empty_pages(struct vm_area_struct *vma, int numpgs)
329{
330 int rc;
331 struct page **pages;
332
333 pages = kcalloc(numpgs, sizeof(pages[0]), GFP_KERNEL);
334 if (pages == NULL)
335 return -ENOMEM;
336
337 rc = alloc_xenballooned_pages(numpgs, pages, 0);
338 if (rc != 0) {
339 pr_warn("%s Could not alloc %d pfns rc:%d\n", __func__,
340 numpgs, rc);
341 kfree(pages);
342 return -ENOMEM;
343 }
344 BUG_ON(vma->vm_private_data != PRIV_VMA_LOCKED);
345 vma->vm_private_data = pages;
346
347 return 0;
348}
349
307static struct vm_operations_struct privcmd_vm_ops; 350static struct vm_operations_struct privcmd_vm_ops;
308 351
309static long privcmd_ioctl_mmap_batch(void __user *udata, int version) 352static long privcmd_ioctl_mmap_batch(void __user *udata, int version)
@@ -371,10 +414,18 @@ static long privcmd_ioctl_mmap_batch(void __user *udata, int version)
371 up_write(&mm->mmap_sem); 414 up_write(&mm->mmap_sem);
372 goto out; 415 goto out;
373 } 416 }
417 if (xen_feature(XENFEAT_auto_translated_physmap)) {
418 ret = alloc_empty_pages(vma, m.num);
419 if (ret < 0) {
420 up_write(&mm->mmap_sem);
421 goto out;
422 }
423 }
374 424
375 state.domain = m.dom; 425 state.domain = m.dom;
376 state.vma = vma; 426 state.vma = vma;
377 state.va = m.addr; 427 state.va = m.addr;
428 state.index = 0;
378 state.global_error = 0; 429 state.global_error = 0;
379 state.err = err_array; 430 state.err = err_array;
380 431
@@ -439,6 +490,19 @@ static long privcmd_ioctl(struct file *file,
439 return ret; 490 return ret;
440} 491}
441 492
493static void privcmd_close(struct vm_area_struct *vma)
494{
495 struct page **pages = vma->vm_private_data;
496 int numpgs = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
497
498 if (!xen_feature(XENFEAT_auto_translated_physmap || !numpgs || !pages))
499 return;
500
501 xen_unmap_domain_mfn_range(vma, numpgs, pages);
502 free_xenballooned_pages(numpgs, pages);
503 kfree(pages);
504}
505
442static int privcmd_fault(struct vm_area_struct *vma, struct vm_fault *vmf) 506static int privcmd_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
443{ 507{
444 printk(KERN_DEBUG "privcmd_fault: vma=%p %lx-%lx, pgoff=%lx, uv=%p\n", 508 printk(KERN_DEBUG "privcmd_fault: vma=%p %lx-%lx, pgoff=%lx, uv=%p\n",
@@ -449,6 +513,7 @@ static int privcmd_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
449} 513}
450 514
451static struct vm_operations_struct privcmd_vm_ops = { 515static struct vm_operations_struct privcmd_vm_ops = {
516 .close = privcmd_close,
452 .fault = privcmd_fault 517 .fault = privcmd_fault
453}; 518};
454 519
@@ -466,7 +531,7 @@ static int privcmd_mmap(struct file *file, struct vm_area_struct *vma)
466 531
467static int privcmd_enforce_singleshot_mapping(struct vm_area_struct *vma) 532static int privcmd_enforce_singleshot_mapping(struct vm_area_struct *vma)
468{ 533{
469 return (xchg(&vma->vm_private_data, (void *)1) == NULL); 534 return !cmpxchg(&vma->vm_private_data, NULL, PRIV_VMA_LOCKED);
470} 535}
471 536
472const struct file_operations xen_privcmd_fops = { 537const struct file_operations xen_privcmd_fops = {