Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge tag 'stable/for-linus-3.14-rc8-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull Xen bugfixes from David Vrabel:
"Fix two bugs that cause x86 PV guest crashes.
1. Ballooning a 32-bit guest would eventually crash it.
2. Revert a broken fix for a regression with NUMA_BALACING. The bad
fix caused PV guests to crash after migration. This is not ideal
but unpicking the madness that is _PAGE_NUMA == _PAGE_PROTNONE will
take a while longer"
* tag 'stable/for-linus-3.14-rc8-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
Revert "xen: properly account for _PAGE_NUMA during xen pte translations"
xen/balloon: flush persistent kmaps in correct position
+23
-21
+2
-12
arch/x86/include/asm/pgtable.h
+2
-12
arch/x86/include/asm/pgtable.h
···
445
445
return a.pte == b.pte;
446
446
}
447
447
448
-
static inline int pteval_present(pteval_t pteval)
449
-
{
450
-
/*
451
-
* Yes Linus, _PAGE_PROTNONE == _PAGE_NUMA. Expressing it this
452
-
* way clearly states that the intent is that protnone and numa
453
-
* hinting ptes are considered present for the purposes of
454
-
* pagetable operations like zapping, protection changes, gup etc.
455
-
*/
456
-
return pteval & (_PAGE_PRESENT | _PAGE_PROTNONE | _PAGE_NUMA);
457
-
}
458
-
459
448
static inline int pte_present(pte_t a)
460
449
{
461
-
return pteval_present(pte_flags(a));
450
+
return pte_flags(a) & (_PAGE_PRESENT | _PAGE_PROTNONE |
451
+
_PAGE_NUMA);
462
452
}
463
453
464
454
#define pte_accessible pte_accessible
+2
-2
arch/x86/xen/mmu.c
+2
-2
arch/x86/xen/mmu.c
···
365
365
/* Assume pteval_t is equivalent to all the other *val_t types. */
366
366
static pteval_t pte_mfn_to_pfn(pteval_t val)
367
367
{
368
-
if (pteval_present(val)) {
368
+
if (val & _PAGE_PRESENT) {
369
369
unsigned long mfn = (val & PTE_PFN_MASK) >> PAGE_SHIFT;
370
370
unsigned long pfn = mfn_to_pfn(mfn);
371
371
···
381
381
382
382
static pteval_t pte_pfn_to_mfn(pteval_t val)
383
383
{
384
-
if (pteval_present(val)) {
384
+
if (val & _PAGE_PRESENT) {
385
385
unsigned long pfn = (val & PTE_PFN_MASK) >> PAGE_SHIFT;
386
386
pteval_t flags = val & PTE_FLAGS_MASK;
387
387
unsigned long mfn;
+19
-7
drivers/xen/balloon.c
+19
-7
drivers/xen/balloon.c
···
399
399
state = BP_EAGAIN;
400
400
break;
401
401
}
402
-
403
-
pfn = page_to_pfn(page);
404
-
frame_list[i] = pfn_to_mfn(pfn);
405
-
406
402
scrub_page(page);
403
+
404
+
frame_list[i] = page_to_pfn(page);
405
+
}
406
+
407
+
/*
408
+
* Ensure that ballooned highmem pages don't have kmaps.
409
+
*
410
+
* Do this before changing the p2m as kmap_flush_unused()
411
+
* reads PTEs to obtain pages (and hence needs the original
412
+
* p2m entry).
413
+
*/
414
+
kmap_flush_unused();
415
+
416
+
/* Update direct mapping, invalidate P2M, and add to balloon. */
417
+
for (i = 0; i < nr_pages; i++) {
418
+
pfn = frame_list[i];
419
+
frame_list[i] = pfn_to_mfn(pfn);
420
+
page = pfn_to_page(pfn);
407
421
408
422
#ifdef CONFIG_XEN_HAVE_PVMMU
409
423
/*
···
443
429
}
444
430
#endif
445
431
446
-
balloon_append(pfn_to_page(pfn));
432
+
balloon_append(page);
447
433
}
448
434
449
-
/* Ensure that ballooned highmem pages don't have kmaps. */
450
-
kmap_flush_unused();
451
435
flush_tlb_all();
452
436
453
437
set_xen_guest_handle(reservation.extent_start, frame_list);