diff --git a/xen/arch/x86/e820.c b/xen/arch/x86/e820.c
index 872208ab37..f09a01f0c5 100644
--- a/xen/arch/x86/e820.c
+++ b/xen/arch/x86/e820.c
@@ -670,7 +670,13 @@ int __init e820_change_range_type(
 /* Set E820_RAM area (@s,@e) as RESERVED in specified e820 map. */
 int __init reserve_e820_ram(struct e820map *map, uint64_t s, uint64_t e)
 {
-    return e820_change_range_type(map, s, e, E820_RAM, E820_RESERVED);
+    int res = e820_change_range_type(map, s, e, E820_RAM, E820_RESERVED);
+
+    if ( !res )
+        printk("Failed to convert E820 RAM %"PRIx64"-%"PRIx64" to RESERVED\n",
+               s, e);
+
+    return res;
 }
 
 unsigned long __init init_e820(const char *str, struct e820map *raw)
diff --git a/xen/arch/x86/include/asm/e820.h b/xen/arch/x86/include/asm/e820.h
index 8e7644f887..55395f8d8a 100644
--- a/xen/arch/x86/include/asm/e820.h
+++ b/xen/arch/x86/include/asm/e820.h
@@ -25,7 +25,8 @@ struct e820map {
 
 extern int sanitize_e820_map(struct e820entry *biosmap, unsigned int *pnr_map);
 extern int e820_all_mapped(u64 start, u64 end, unsigned type);
-extern int reserve_e820_ram(struct e820map *map, uint64_t s, uint64_t e);
+extern int __must_check reserve_e820_ram(
+    struct e820map *map, uint64_t s, uint64_t e);
 extern int e820_change_range_type(
     struct e820map *map, uint64_t s, uint64_t e,
     uint32_t orig_type, uint32_t new_type);
diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
index 7d71fea6c0..23d14aa718 100644
--- a/xen/arch/x86/setup.c
+++ b/xen/arch/x86/setup.c
@@ -1648,7 +1648,8 @@ void asmlinkage __init noreturn __start_xen(void)
     {
         uint64_t s = bi->mods[i].start, l = bi->mods[i].size;
 
-        reserve_e820_ram(&boot_e820, s, s + PAGE_ALIGN(l));
+        if ( !reserve_e820_ram(&boot_e820, s, s + PAGE_ALIGN(l)) )
+            panic("Failed to reserve boot module %u in E820\n", i);
     }
 
     if ( !xen_phys_start )
@@ -1661,11 +1662,13 @@ void asmlinkage __init noreturn __start_xen(void)
     /* This needs to remain in sync with remove_xen_ranges(). */
     if ( efi_boot_mem_unused(&eb_start, &eb_end) )
     {
-        reserve_e820_ram(&boot_e820, __pa(_stext), __pa(eb_start));
-        reserve_e820_ram(&boot_e820, __pa(eb_end), __pa(__2M_rwdata_end));
+        if ( !reserve_e820_ram(&boot_e820, __pa(_stext), __pa(eb_start)) ||
+             !reserve_e820_ram(&boot_e820, __pa(eb_end), __pa(__2M_rwdata_end)) )
+            panic("Failed to reserve Xen in E820\n");
     }
     else
-        reserve_e820_ram(&boot_e820, __pa(_stext), __pa(__2M_rwdata_end));
+        if ( !reserve_e820_ram(&boot_e820, __pa(_stext), __pa(__2M_rwdata_end)) )
+            panic("Failed to reserve Xen in E820\n");
 
     /* Late kexec reservation (dynamic start address). */
     kexec_reserve_area();