From 5926f87fdaad4be3ed10cec563bf357915e55a86 Mon Sep 17 00:00:00 2001 From: David Vrabel Date: Tue, 25 Mar 2014 10:38:37 +0000 Subject: Revert "xen: properly account for _PAGE_NUMA during xen pte translations" This reverts commit a9c8e4beeeb64c22b84c803747487857fe424b68. PTEs in Xen PV guests must contain machine addresses if _PAGE_PRESENT is set and pseudo-physical addresses is _PAGE_PRESENT is clear. This is because during a domain save/restore (migration) the page table entries are "canonicalised" and uncanonicalised". i.e., MFNs are converted to PFNs during domain save so that on a restore the page table entries may be rewritten with the new MFNs on the destination. This canonicalisation is only done for PTEs that are present. This change resulted in writing PTEs with MFNs if _PAGE_PROTNONE (or _PAGE_NUMA) was set but _PAGE_PRESENT was clear. These PTEs would be migrated as-is which would result in unexpected behaviour in the destination domain. Either a) the MFN would be translated to the wrong PFN/page; b) setting the _PAGE_PRESENT bit would clear the PTE because the MFN is no longer owned by the domain; or c) the present bit would not get set. Symptoms include "Bad page" reports when munmapping after migrating a domain. Signed-off-by: David Vrabel Acked-by: Konrad Rzeszutek Wilk Cc: [3.12+] --- arch/x86/include/asm/pgtable.h | 14 ++------------ arch/x86/xen/mmu.c | 4 ++-- 2 files changed, 4 insertions(+), 14 deletions(-) (limited to 'arch') 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; -- cgit v1.2.3 From 825600c0f20e595daaa7a6dd8970f84fa2a2ee57 Mon Sep 17 00:00:00 2001 From: Artem Fetishev Date: Fri, 28 Mar 2014 13:33:39 -0700 Subject: x86: fix boot on uniprocessor systems On x86 uniprocessor systems topology_physical_package_id() returns -1 which causes rapl_cpu_prepare() to leave rapl_pmu variable uninitialized which leads to GPF in rapl_pmu_init(). See arch/x86/kernel/cpu/perf_event_intel_rapl.c. It turns out that physical_package_id and core_id can actually be retreived for uniprocessor systems too. Enabling them also fixes rapl_pmu code. Signed-off-by: Artem Fetishev Cc: Stephane Eranian Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Thomas Gleixner Cc: Peter Zijlstra Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/x86/include/asm/topology.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'arch') diff --git a/arch/x86/include/asm/topology.h b/arch/x86/include/asm/topology.h index d35f24e231cd..1306d117967d 100644 --- a/arch/x86/include/asm/topology.h +++ b/arch/x86/include/asm/topology.h @@ -119,9 +119,10 @@ static inline void setup_node_to_cpumask_map(void) { } extern const struct cpumask *cpu_coregroup_mask(int cpu); -#ifdef ENABLE_TOPO_DEFINES #define topology_physical_package_id(cpu) (cpu_data(cpu).phys_proc_id) #define topology_core_id(cpu) (cpu_data(cpu).cpu_core_id) + +#ifdef ENABLE_TOPO_DEFINES #define topology_core_cpumask(cpu) (per_cpu(cpu_core_map, cpu)) #define topology_thread_cpumask(cpu) (per_cpu(cpu_sibling_map, cpu)) #endif -- cgit v1.2.3