commit a273a71b86523d2a81ba0fdd2a402cc2db70a7e2
Author: Jan Rękorajski <[email protected]>
Date: Wed Jun 4 13:20:09 2014 +0200
- Xen PVM PTE breakage fixed upstream
kernel-small_fixes.patch | 106 -----------------------------------------------
1 file changed, 106 deletions(-)
---
diff --git a/kernel-small_fixes.patch b/kernel-small_fixes.patch
index ab5a074..c64eee1 100644
--- a/kernel-small_fixes.patch
+++ b/kernel-small_fixes.patch
@@ -71,112 +71,6 @@ index 3b1ea34..eaa808e 100644
result = scsi_vpd_inquiry(sdev, buf, 0, buf_len);
if (result)
-David Vrabel identified a regression when using automatic NUMA balancing
-under Xen whereby page table entries were getting corrupted due to the
-use of native PTE operations. Quoting him
-
- Xen PV guest page tables require that their entries use machine
- addresses if the preset bit (_PAGE_PRESENT) is set, and (for
- successful migration) non-present PTEs must use pseudo-physical
- addresses. This is because on migration MFNs in present PTEs are
- translated to PFNs (canonicalised) so they may be translated back
- to the new MFN in the destination domain (uncanonicalised).
-
- pte_mknonnuma(), pmd_mknonnuma(), pte_mknuma() and pmd_mknuma()
- set and clear the _PAGE_PRESENT bit using pte_set_flags(),
- pte_clear_flags(), etc.
-
- In a Xen PV guest, these functions must translate MFNs to PFNs
- when clearing _PAGE_PRESENT and translate PFNs to MFNs when setting
- _PAGE_PRESENT.
-
-His suggested fix converted p[te|md]_[set|clear]_flags to using
-paravirt-friendly ops but this is overkill. He suggested an alternative of
-using p[te|md]_modify in the NUMA page table operations but this is does
-more work than necessary and would require looking up a VMA for protections.
-
-This patch modifies the NUMA page table operations to use paravirt friendly
-operations to set/clear the flags of interest. Unfortunately this will take
-a performance hit when updating the PTEs on CONFIG_PARAVIRT but I do not
-see a way around it that does not break Xen.
-
-Cc: [email protected]
-Signed-off-by: Mel Gorman <[email protected]>
-Acked-by: David Vrabel <[email protected]>
-Tested-by: David Vrabel <[email protected]>
----
- include/asm-generic/pgtable.h | 31 +++++++++++++++++++++++--------
- 1 file changed, 23 insertions(+), 8 deletions(-)
-
-diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h
-index 34c7bdc..38a7437 100644
---- a/include/asm-generic/pgtable.h
-+++ b/include/asm-generic/pgtable.h
-@@ -680,24 +680,35 @@ static inline int pmd_numa(pmd_t pmd)
- #ifndef pte_mknonnuma
- static inline pte_t pte_mknonnuma(pte_t pte)
- {
-- pte = pte_clear_flags(pte, _PAGE_NUMA);
-- return pte_set_flags(pte, _PAGE_PRESENT|_PAGE_ACCESSED);
-+ pteval_t val = pte_val(pte);
-+
-+ val &= ~_PAGE_NUMA;
-+ val |= (_PAGE_PRESENT|_PAGE_ACCESSED);
-+ return __pte(val);
- }
- #endif
-
- #ifndef pmd_mknonnuma
- static inline pmd_t pmd_mknonnuma(pmd_t pmd)
- {
-- pmd = pmd_clear_flags(pmd, _PAGE_NUMA);
-- return pmd_set_flags(pmd, _PAGE_PRESENT|_PAGE_ACCESSED);
-+ pmdval_t val = pmd_val(pmd);
-+
-+ val &= ~_PAGE_NUMA;
-+ val |= (_PAGE_PRESENT|_PAGE_ACCESSED);
-+
-+ return __pmd(val);
- }
- #endif
-
- #ifndef pte_mknuma
- static inline pte_t pte_mknuma(pte_t pte)
- {
-- pte = pte_set_flags(pte, _PAGE_NUMA);
-- return pte_clear_flags(pte, _PAGE_PRESENT);
-+ pteval_t val = pte_val(pte);
-+
-+ val &= ~_PAGE_PRESENT;
-+ val |= _PAGE_NUMA;
-+
-+ return __pte(val);
- }
- #endif
-
-@@ -716,8 +727,12 @@ static inline void ptep_set_numa(struct mm_struct *mm,
unsigned long addr,
- #ifndef pmd_mknuma
- static inline pmd_t pmd_mknuma(pmd_t pmd)
- {
-- pmd = pmd_set_flags(pmd, _PAGE_NUMA);
-- return pmd_clear_flags(pmd, _PAGE_PRESENT);
-+ pmdval_t val = pmd_val(pmd);
-+
-+ val &= ~_PAGE_PRESENT;
-+ val |= _PAGE_NUMA;
-+
-+ return __pmd(val);
- }
- #endif
-
---
-1.8.4.5
-
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From 1e2ee49f7f1b79f0b14884fe6a602f0411b39552 Mon Sep 17 00:00:00 2001
From: Will Woods <[email protected]>
Date: Tue, 6 May 2014 12:50:10 -0700
================================================================
---- gitweb:
http://git.pld-linux.org/gitweb.cgi/packages/kernel.git/commitdiff/a273a71b86523d2a81ba0fdd2a402cc2db70a7e2
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