File 23506-x86_Disable_set_gpfn_from_mfn_until_m2p_t... of Package xen

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File 23506-x86_Disable_set_gpfn_from_mfn_until_m2p_table_is_allocated..patch of Package xen (Revision e038a0d12ee40acfadb0758f86c2788d)

Currently displaying revision e038a0d12ee40acfadb0758f86c2788d , Show latest

changeset:   23506:d1309a79bde8
user:        Keir Fraser <keir@xen.org>
date:        Fri Jun 10 08:18:33 2011 +0100
files:       xen/arch/x86/x86_64/mm.c xen/include/asm-x86/mm.h
description:
x86: Disable set_gpfn_from_mfn until m2p table is allocated.

This is a prerequisite for calling set_gpfn_from_mfn() unconditionally
from free_heap_pages().

Signed-off-by: Keir Fraser <keir@xen.org>

---
 xen/arch/x86/x86_64/mm.c |    4 ++++
 xen/include/asm-x86/mm.h |   15 +++++++++++++--
 2 files changed, 17 insertions(+), 2 deletions(-)

Index: xen-4.1.2-testing/xen/arch/x86/x86_64/mm.c
===================================================================
--- xen-4.1.2-testing.orig/xen/arch/x86/x86_64/mm.c
+++ xen-4.1.2-testing/xen/arch/x86/x86_64/mm.c
@@ -47,6 +47,8 @@ unsigned int __read_mostly pfn_pdx_hole_
 
 unsigned int __read_mostly m2p_compat_vstart = __HYPERVISOR_COMPAT_VIRT_START;
 
+bool_t __read_mostly machine_to_phys_mapping_valid = 0;
+
 /* Top-level master (and idle-domain) page directory. */
 l4_pgentry_t __attribute__ ((__section__ (".bss.page_aligned")))
     idle_pg_table[L4_PAGETABLE_ENTRIES];
@@ -800,6 +802,8 @@ void __init paging_init(void)
 #undef CNT
 #undef MFN
 
+    machine_to_phys_mapping_valid = 1;
+
     /* Set up linear page table mapping. */
     l4e_write(&idle_pg_table[l4_table_offset(LINEAR_PT_VIRT_START)],
               l4e_from_paddr(__pa(idle_pg_table), __PAGE_HYPERVISOR));
Index: xen-4.1.2-testing/xen/include/asm-x86/mm.h
===================================================================
--- xen-4.1.2-testing.orig/xen/include/asm-x86/mm.h
+++ xen-4.1.2-testing/xen/include/asm-x86/mm.h
@@ -469,7 +469,7 @@ TYPE_SAFE(unsigned long,mfn);
 
 #ifdef CONFIG_COMPAT
 #define compat_machine_to_phys_mapping ((unsigned int *)RDWR_COMPAT_MPT_VIRT_START)
-#define set_gpfn_from_mfn(mfn, pfn) ({                         \
+#define _set_gpfn_from_mfn(mfn, pfn) ({                        \
     struct domain *d = page_get_owner(__mfn_to_page(mfn));     \
     unsigned long entry = (d && (d == dom_cow)) ?              \
         SHARED_M2P_ENTRY : (pfn);                              \
@@ -478,7 +478,7 @@ TYPE_SAFE(unsigned long,mfn);
      machine_to_phys_mapping[(mfn)] = (entry));                \
     })
 #else
-#define set_gpfn_from_mfn(mfn, pfn) ({                         \
+#define _set_gpfn_from_mfn(mfn, pfn) ({                        \
     struct domain *d = page_get_owner(__mfn_to_page(mfn));     \
     if(d && (d == dom_cow))                                    \
         machine_to_phys_mapping[(mfn)] = SHARED_M2P_ENTRY;     \
@@ -486,6 +486,17 @@ TYPE_SAFE(unsigned long,mfn);
         machine_to_phys_mapping[(mfn)] = (pfn);                \
     })
 #endif
+
+/*
+ * Disable some users of set_gpfn_from_mfn() (e.g., free_heap_pages()) until
+ * the machine_to_phys_mapping is actually set up.
+ */
+extern bool_t machine_to_phys_mapping_valid;
+#define set_gpfn_from_mfn(mfn, pfn) do {        \
+    if ( machine_to_phys_mapping_valid )        \
+        _set_gpfn_from_mfn(mfn, pfn);           \
+} while (0)
+
 #define get_gpfn_from_mfn(mfn)      (machine_to_phys_mapping[(mfn)])
 
 #define mfn_to_gmfn(_d, mfn)                            \

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File 23506-x86_Disable_set_gpfn_from_mfn_until_m2p_table_is_allocated..patch of Package xen (Revision e038a0d12ee40acfadb0758f86c2788d)

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