[PATCH] x86: E801 memory "map" use implies no ACPI

[Jan Beulich <jbeulich@xxxxxxxx>]

ACPI mandates use of E820 (or newer, e.g. EFI), and in fact firmware
has been observed to include E820_ACPI ranges in what E801 reports as
available (really "configured") memory.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
---
TBD: Alternatively we could drop all use of E801 (and older), since
     there shouldn't be any 64-bit systems not supporting the more
     modern E820.

--- a/xen/arch/x86/setup.c
+++ b/xen/arch/x86/setup.c
@@ -74,7 +74,7 @@ bool __read_mostly use_invpcid;
 unsigned long __read_mostly cr4_pv32_mask;
 
 /* **** Linux config option: propagated to domain0. */
-/* "acpi=off":    Sisables both ACPI table parsing and interpreter. */
+/* "acpi=off":    Disables both ACPI table parsing and interpreter. */
 /* "acpi=force":  Override the disable blacklist.                   */
 /* "acpi=ht":     Limit ACPI just to boot-time to enable HT.        */
 /* "acpi=noirq":  Disables ACPI interrupt routing.                  */
@@ -1069,6 +1069,7 @@ void __init noreturn __start_xen(unsigne
         e820_raw.map[1].size = bootsym(highmem_kb) << 10;
         e820_raw.map[1].type = E820_RAM;
         e820_raw.nr_map = 2;
+        disable_acpi();
     }
     else if ( mbi->flags & MBI_MEMLIMITS )
     {
@@ -1080,6 +1081,7 @@ void __init noreturn __start_xen(unsigne
         e820_raw.map[1].size = mbi->mem_upper << 10;
         e820_raw.map[1].type = E820_RAM;
         e820_raw.nr_map = 2;
+        disable_acpi();
     }
     else
         panic("Bootloader provided no memory information\n");