File x86-show-page-walk-early.patch of Package xen

--- a/xen/arch/x86/traps.c
+++ b/xen/arch/x86/traps.c
@@ -1302,6 +1302,7 @@ asmlinkage void do_early_page_fault(stru
         unsigned long *stk = (unsigned long *)regs;
         printk("Early fatal page fault at %04x:%p (cr2=%p, ec=%04x)\n", 
                regs->cs, _p(regs->eip), _p(cr2), regs->error_code);
+        show_page_walk(cr2);
         printk("Stack dump: ");
         while ( ((long)stk & ((PAGE_SIZE - 1) & ~(BYTES_PER_LONG - 1))) != 0 )
             printk("%p ", _p(*stk++));
--- a/xen/arch/x86/x86_32/mm.c
+++ b/xen/arch/x86/x86_32/mm.c
@@ -38,6 +38,7 @@ extern l1_pgentry_t l1_identmap[L1_PAGET
 unsigned int PAGE_HYPERVISOR         = __PAGE_HYPERVISOR;
 unsigned int PAGE_HYPERVISOR_NOCACHE = __PAGE_HYPERVISOR_NOCACHE;
 
+int mpt_valid;
 static unsigned long mpt_size;
 
 void *alloc_xen_pagetable(void)
@@ -108,6 +109,8 @@ void __init paging_init(void)
                       pg, (__PAGE_HYPERVISOR | _PAGE_PSE) & ~_PAGE_RW));
     }
 
+    mpt_valid = 1;
+
     /* Fill with an obvious debug pattern. */
     for ( i = 0; i < (mpt_size / BYTES_PER_LONG); i++)
         set_gpfn_from_mfn(i, 0x55555555);
--- a/xen/arch/x86/x86_32/traps.c
+++ b/xen/arch/x86/x86_32/traps.c
@@ -160,7 +160,8 @@ void show_page_walk(unsigned long addr)
     l3t += (cr3 & 0xFE0UL) >> 3;
     l3e = l3t[l3_table_offset(addr)];
     mfn = l3e_get_pfn(l3e);
-    pfn = mfn_valid(mfn) ? get_gpfn_from_mfn(mfn) : INVALID_M2P_ENTRY;
+    pfn = mfn_valid(mfn) && mpt_valid ?
+          get_gpfn_from_mfn(mfn) : INVALID_M2P_ENTRY;
     printk(" L3[0x%03lx] = %"PRIpte" %08lx\n",
            l3_table_offset(addr), l3e_get_intpte(l3e), pfn);
     unmap_domain_page(l3t);
@@ -171,7 +172,8 @@ void show_page_walk(unsigned long addr)
     l2t = map_domain_page(mfn);
     l2e = l2t[l2_table_offset(addr)];
     mfn = l2e_get_pfn(l2e);
-    pfn = mfn_valid(mfn) ? get_gpfn_from_mfn(mfn) : INVALID_M2P_ENTRY;
+    pfn = mfn_valid(mfn) && mpt_valid ?
+          get_gpfn_from_mfn(mfn) : INVALID_M2P_ENTRY;
     printk(" L2[0x%03lx] = %"PRIpte" %08lx %s\n",
            l2_table_offset(addr), l2e_get_intpte(l2e), pfn,
            (l2e_get_flags(l2e) & _PAGE_PSE) ? "(PSE)" : "");
@@ -184,7 +186,8 @@ void show_page_walk(unsigned long addr)
     l1t = map_domain_page(mfn);
     l1e = l1t[l1_table_offset(addr)];
     mfn = l1e_get_pfn(l1e);
-    pfn = mfn_valid(mfn) ? get_gpfn_from_mfn(mfn) : INVALID_M2P_ENTRY;
+    pfn = mfn_valid(mfn) && mpt_valid ?
+          get_gpfn_from_mfn(mfn) : INVALID_M2P_ENTRY;
     printk(" L1[0x%03lx] = %"PRIpte" %08lx\n",
            l1_table_offset(addr), l1e_get_intpte(l1e), pfn);
     unmap_domain_page(l1t);
--- a/xen/arch/x86/x86_64/mm.c
+++ b/xen/arch/x86/x86_64/mm.c
@@ -33,6 +33,8 @@
 #include <asm/msr.h>
 #include <public/memory.h>
 
+int mpt_valid;
+
 #ifdef CONFIG_COMPAT
 unsigned int m2p_compat_vstart = __HYPERVISOR_COMPAT_VIRT_START;
 #endif
@@ -223,6 +225,8 @@ void __init paging_init(void)
         l2_ro_mpt++;
     }
 
+    mpt_valid = 1;
+
     /* Create user-accessible L2 directory to map the MPT for compat guests. */
     BUILD_BUG_ON(l4_table_offset(RDWR_MPT_VIRT_START) !=
                  l4_table_offset(HIRO_COMPAT_MPT_VIRT_START));
--- a/xen/arch/x86/x86_64/traps.c
+++ b/xen/arch/x86/x86_64/traps.c
@@ -174,7 +174,8 @@ void show_page_walk(unsigned long addr)
     l4t = mfn_to_virt(mfn);
     l4e = l4t[l4_table_offset(addr)];
     mfn = l4e_get_pfn(l4e);
-    pfn = mfn_valid(mfn) ? get_gpfn_from_mfn(mfn) : INVALID_M2P_ENTRY;
+    pfn = mfn_valid(mfn) && mpt_valid ?
+          get_gpfn_from_mfn(mfn) : INVALID_M2P_ENTRY;
     printk(" L4[0x%03lx] = %"PRIpte" %016lx\n",
            l4_table_offset(addr), l4e_get_intpte(l4e), pfn);
     if ( !(l4e_get_flags(l4e) & _PAGE_PRESENT) ||
@@ -184,7 +185,8 @@ void show_page_walk(unsigned long addr)
     l3t = mfn_to_virt(mfn);
     l3e = l3t[l3_table_offset(addr)];
     mfn = l3e_get_pfn(l3e);
-    pfn = mfn_valid(mfn) ? get_gpfn_from_mfn(mfn) : INVALID_M2P_ENTRY;
+    pfn = mfn_valid(mfn) && mpt_valid ?
+          get_gpfn_from_mfn(mfn) : INVALID_M2P_ENTRY;
     printk(" L3[0x%03lx] = %"PRIpte" %016lx%s\n",
            l3_table_offset(addr), l3e_get_intpte(l3e), pfn,
            (l3e_get_flags(l3e) & _PAGE_PSE) ? " (PSE)" : "");
@@ -196,7 +198,8 @@ void show_page_walk(unsigned long addr)
     l2t = mfn_to_virt(mfn);
     l2e = l2t[l2_table_offset(addr)];
     mfn = l2e_get_pfn(l2e);
-    pfn = mfn_valid(mfn) ? get_gpfn_from_mfn(mfn) : INVALID_M2P_ENTRY;
+    pfn = mfn_valid(mfn) && mpt_valid ?
+          get_gpfn_from_mfn(mfn) : INVALID_M2P_ENTRY;
     printk(" L2[0x%03lx] = %"PRIpte" %016lx %s\n",
            l2_table_offset(addr), l2e_get_intpte(l2e), pfn,
            (l2e_get_flags(l2e) & _PAGE_PSE) ? "(PSE)" : "");
@@ -208,7 +211,8 @@ void show_page_walk(unsigned long addr)
     l1t = mfn_to_virt(mfn);
     l1e = l1t[l1_table_offset(addr)];
     mfn = l1e_get_pfn(l1e);
-    pfn = mfn_valid(mfn) ? get_gpfn_from_mfn(mfn) : INVALID_M2P_ENTRY;
+    pfn = mfn_valid(mfn) && mpt_valid ?
+          get_gpfn_from_mfn(mfn) : INVALID_M2P_ENTRY;
     printk(" L1[0x%03lx] = %"PRIpte" %016lx\n",
            l1_table_offset(addr), l1e_get_intpte(l1e), pfn);
 }
--- a/xen/include/asm-x86/mm.h
+++ b/xen/include/asm-x86/mm.h
@@ -394,6 +394,7 @@ TYPE_SAFE(unsigned long,mfn);
 #define machine_to_phys_mapping  ((unsigned long *)RDWR_MPT_VIRT_START)
 #define INVALID_M2P_ENTRY        (~0UL)
 #define VALID_M2P(_e)            (!((_e) & (1UL<<(BITS_PER_LONG-1))))
+extern int mpt_valid;
 
 #ifdef CONFIG_COMPAT
 #define compat_machine_to_phys_mapping ((unsigned int *)RDWR_COMPAT_MPT_VIRT_START)