EFI/early: add /mapbs to map EfiBootServices{Code,Data}

From: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>

To help on certain platforms to run.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

--- a/xen/arch/x86/efi/efi-boot.h
+++ b/xen/arch/x86/efi/efi-boot.h
@@ -148,12 +148,16 @@ static void __init efi_arch_process_memo
 
         switch ( desc->Type )
         {
-        default:
-            type = E820_RESERVED;
-            break;
-        case EfiConventionalMemory:
         case EfiBootServicesCode:
         case EfiBootServicesData:
+            if ( map_bs )
+            {
+        default:
+                type = E820_RESERVED;
+                break;
+            }
+            /* fall through */
+        case EfiConventionalMemory:
             if ( !trampoline_phys && desc->PhysicalStart + len <= 0x100000 &&
                  len >= cfg.size && desc->PhysicalStart + len > cfg.addr )
                 cfg.addr = (desc->PhysicalStart + len - cfg.size) & PAGE_MASK;
--- a/xen/common/efi/boot.c
+++ b/xen/common/efi/boot.c
@@ -84,6 +84,7 @@ static SIMPLE_TEXT_OUTPUT_INTERFACE *__i
 static SIMPLE_TEXT_OUTPUT_INTERFACE *__initdata StdErr;
 
 static UINT32 __initdata mdesc_ver;
+static bool_t __initdata map_bs;
 
 static struct file __initdata cfg;
 static struct file __initdata kernel;
@@ -753,6 +754,8 @@ efi_start(EFI_HANDLE ImageHandle, EFI_SY
             {
                 if ( wstrcmp(ptr + 1, L"basevideo") == 0 )
                     base_video = 1;
+                else if ( wstrcmp(ptr + 1, L"mapbs") == 0 )
+                    map_bs = 1;
                 else if ( wstrncmp(ptr + 1, L"cfg=", 4) == 0 )
                     cfg_file_name = ptr + 5;
                 else if ( i + 1 < argc && wstrcmp(ptr + 1, L"cfg") == 0 )
@@ -762,6 +765,7 @@ efi_start(EFI_HANDLE ImageHandle, EFI_SY
                 {
                     PrintStr(L"Xen EFI Loader options:\r\n");
                     PrintStr(L"-basevideo   retain current video mode\r\n");
+                    PrintStr(L"-mapbs       map EfiBootServices{Code,Data}\r\n");
                     PrintStr(L"-cfg=<file>  specify configuration file\r\n");
                     PrintStr(L"-help, -?    display this help\r\n");
                     blexit(NULL);
@@ -1158,7 +1162,8 @@ void __init efi_init_memory(void)
     } *extra, *extra_head = NULL;
 #endif
 
-    printk(XENLOG_INFO "EFI memory map:\n");
+    printk(XENLOG_INFO "EFI memory map:%s\n",
+           map_bs ? " (mapping BootServices)" : "");
     for ( i = 0; i < efi_memmap_size; i += efi_mdesc_size )
     {
         EFI_MEMORY_DESCRIPTOR *desc = efi_memmap + i;
@@ -1171,7 +1176,11 @@ void __init efi_init_memory(void)
                desc->PhysicalStart, desc->PhysicalStart + len - 1,
                desc->Type, desc->Attribute);
 
-        if ( !efi_rs_enable || !(desc->Attribute & EFI_MEMORY_RUNTIME) )
+        if ( !efi_rs_enable ||
+             (!(desc->Attribute & EFI_MEMORY_RUNTIME) &&
+              (!map_bs ||
+               (desc->Type != EfiBootServicesCode &&
+                desc->Type != EfiBootServicesData))) )
             continue;
 
         desc->VirtualStart = INVALID_VIRTUAL_ADDRESS;
@@ -1257,7 +1266,10 @@ void __init efi_init_memory(void)
     {
         const EFI_MEMORY_DESCRIPTOR *desc = efi_memmap + i;
 
-        if ( (desc->Attribute & EFI_MEMORY_RUNTIME) &&
+        if ( ((desc->Attribute & EFI_MEMORY_RUNTIME) ||
+              (map_bs &&
+               (desc->Type == EfiBootServicesCode ||
+                desc->Type == EfiBootServicesData))) &&
              desc->VirtualStart != INVALID_VIRTUAL_ADDRESS &&
              desc->VirtualStart != desc->PhysicalStart )
             copy_mapping(PFN_DOWN(desc->PhysicalStart),