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authorLinus Torvalds <torvalds@linux-foundation.org>2012-02-26 21:03:16 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2012-02-26 21:03:16 -0800
commit500dd2370e77c9551ba298bdeeb91b02d8402199 (patch)
treea1e94caef4032fec934aee7da34d6551a80e7da7
parentf6bd5798f3b7583f7e984f8408ffb5b36ece174f (diff)
parent8eaffa67b43e99ae581622c5133e20b0f48bcef1 (diff)
Merge tag 'stable/for-linus-fixes-3.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
Two fixes to fix a memory corruption bug when WC pages never get converted back to WB but end up being recycled in the general memory pool as WC. There is a better way of fixing this, but there is not enough time to do the full benchmarking to pick one of the right options - so picking the one that favors stability for right now. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> * tag 'stable/for-linus-fixes-3.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: xen/pat: Disable PAT support for now. xen/setup: Remove redundant filtering of PTE masks.
-rw-r--r--arch/x86/xen/enlighten.c6
-rw-r--r--arch/x86/xen/mmu.c8
2 files changed, 6 insertions, 8 deletions
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 12eb07bfb267..4172af8ceeb3 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1141,7 +1141,9 @@ asmlinkage void __init xen_start_kernel(void)
/* Prevent unwanted bits from being set in PTEs. */
__supported_pte_mask &= ~_PAGE_GLOBAL;
+#if 0
if (!xen_initial_domain())
+#endif
__supported_pte_mask &= ~(_PAGE_PWT | _PAGE_PCD);
__supported_pte_mask |= _PAGE_IOMAP;
@@ -1204,10 +1206,6 @@ asmlinkage void __init xen_start_kernel(void)
pgd = (pgd_t *)xen_start_info->pt_base;
- if (!xen_initial_domain())
- __supported_pte_mask &= ~(_PAGE_PWT | _PAGE_PCD);
-
- __supported_pte_mask |= _PAGE_IOMAP;
/* Don't do the full vcpu_info placement stuff until we have a
possible map and a non-dummy shared_info. */
per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0];
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index 58a0e46c404d..95c1cf60c669 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -415,13 +415,13 @@ static pteval_t iomap_pte(pteval_t val)
static pteval_t xen_pte_val(pte_t pte)
{
pteval_t pteval = pte.pte;
-
+#if 0
/* If this is a WC pte, convert back from Xen WC to Linux WC */
if ((pteval & (_PAGE_PAT | _PAGE_PCD | _PAGE_PWT)) == _PAGE_PAT) {
WARN_ON(!pat_enabled);
pteval = (pteval & ~_PAGE_PAT) | _PAGE_PWT;
}
-
+#endif
if (xen_initial_domain() && (pteval & _PAGE_IOMAP))
return pteval;
@@ -463,7 +463,7 @@ void xen_set_pat(u64 pat)
static pte_t xen_make_pte(pteval_t pte)
{
phys_addr_t addr = (pte & PTE_PFN_MASK);
-
+#if 0
/* If Linux is trying to set a WC pte, then map to the Xen WC.
* If _PAGE_PAT is set, then it probably means it is really
* _PAGE_PSE, so avoid fiddling with the PAT mapping and hope
@@ -476,7 +476,7 @@ static pte_t xen_make_pte(pteval_t pte)
if ((pte & (_PAGE_PCD | _PAGE_PWT)) == _PAGE_PWT)
pte = (pte & ~(_PAGE_PCD | _PAGE_PWT)) | _PAGE_PAT;
}
-
+#endif
/*
* Unprivileged domains are allowed to do IOMAPpings for
* PCI passthrough, but not map ISA space. The ISA