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authorLinus Torvalds <torvalds@linux-foundation.org>2014-03-28 10:52:05 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-03-28 10:52:05 -0700
commit81250437a55044edf16d2cc484da4fb837489317 (patch)
tree07f12a763928ed767fd39be4c6d35bfc28d30aea
parent75c5a52da3fc2a06abb6c6192bdf5d680e56d37d (diff)
parent5926f87fdaad4be3ed10cec563bf357915e55a86 (diff)
downloadlinux-81250437a55044edf16d2cc484da4fb837489317.tar.bz2
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
-rw-r--r--arch/x86/include/asm/pgtable.h14
-rw-r--r--arch/x86/xen/mmu.c4
-rw-r--r--drivers/xen/balloon.c24
3 files changed, 22 insertions, 20 deletions
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 5ad38ad07890..bbc8b12fa443 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -445,20 +445,10 @@ static inline int pte_same(pte_t a, pte_t b)
return a.pte == b.pte;
}
-static inline int pteval_present(pteval_t pteval)
-{
- /*
- * Yes Linus, _PAGE_PROTNONE == _PAGE_NUMA. Expressing it this
- * way clearly states that the intent is that protnone and numa
- * hinting ptes are considered present for the purposes of
- * pagetable operations like zapping, protection changes, gup etc.
- */
- return pteval & (_PAGE_PRESENT | _PAGE_PROTNONE | _PAGE_NUMA);
-}
-
static inline int pte_present(pte_t a)
{
- return pteval_present(pte_flags(a));
+ return pte_flags(a) & (_PAGE_PRESENT | _PAGE_PROTNONE |
+ _PAGE_NUMA);
}
#define pte_accessible pte_accessible
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index 256282e7888b..2423ef04ffea 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -365,7 +365,7 @@ void xen_ptep_modify_prot_commit(struct mm_struct *mm, unsigned long addr,
/* Assume pteval_t is equivalent to all the other *val_t types. */
static pteval_t pte_mfn_to_pfn(pteval_t val)
{
- if (pteval_present(val)) {
+ if (val & _PAGE_PRESENT) {
unsigned long mfn = (val & PTE_PFN_MASK) >> PAGE_SHIFT;
unsigned long pfn = mfn_to_pfn(mfn);
@@ -381,7 +381,7 @@ static pteval_t pte_mfn_to_pfn(pteval_t val)
static pteval_t pte_pfn_to_mfn(pteval_t val)
{
- if (pteval_present(val)) {
+ if (val & _PAGE_PRESENT) {
unsigned long pfn = (val & PTE_PFN_MASK) >> PAGE_SHIFT;
pteval_t flags = val & PTE_FLAGS_MASK;
unsigned long mfn;
diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index 37d06ea624aa..61a6ac8fa8fc 100644
--- a/drivers/xen/balloon.c
+++ b/drivers/xen/balloon.c
@@ -399,11 +399,25 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp)
state = BP_EAGAIN;
break;
}
+ scrub_page(page);
- pfn = page_to_pfn(page);
- frame_list[i] = pfn_to_mfn(pfn);
+ frame_list[i] = page_to_pfn(page);
+ }
- scrub_page(page);
+ /*
+ * Ensure that ballooned highmem pages don't have kmaps.
+ *
+ * Do this before changing the p2m as kmap_flush_unused()
+ * reads PTEs to obtain pages (and hence needs the original
+ * p2m entry).
+ */
+ kmap_flush_unused();
+
+ /* Update direct mapping, invalidate P2M, and add to balloon. */
+ for (i = 0; i < nr_pages; i++) {
+ pfn = frame_list[i];
+ frame_list[i] = pfn_to_mfn(pfn);
+ page = pfn_to_page(pfn);
#ifdef CONFIG_XEN_HAVE_PVMMU
/*
@@ -429,11 +443,9 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp)
}
#endif
- balloon_append(pfn_to_page(pfn));
+ balloon_append(page);
}
- /* Ensure that ballooned highmem pages don't have kmaps. */
- kmap_flush_unused();
flush_tlb_all();
set_xen_guest_handle(reservation.extent_start, frame_list);