Initialise multiboot_ptr and pvh_start_info_pa from C code.

Signed-off-by: Frediano Ziglio <frediano.ziglio@cloud.com>
---
 xen/arch/x86/boot/build32.lds.S           |  3 +++
 xen/arch/x86/boot/head.S                  | 10 --------
 xen/arch/x86/boot/reloc.c                 | 28 ++++++++++++++++++-----
 xen/arch/x86/include/asm/guest/pvh-boot.h |  1 +
 4 files changed, 26 insertions(+), 16 deletions(-)

diff --git a/xen/arch/x86/boot/build32.lds.S b/xen/arch/x86/boot/build32.lds.S
index 1e59732edd..1726c17c88 100644
--- a/xen/arch/x86/boot/build32.lds.S
+++ b/xen/arch/x86/boot/build32.lds.S
@@ -51,6 +51,9 @@ SECTIONS
         DECLARE_IMPORT(__trampoline_seg_stop);
         DECLARE_IMPORT(trampoline_phys);
         DECLARE_IMPORT(boot_vid_info);
+        DECLARE_IMPORT(multiboot_ptr);
+        DECLARE_IMPORT(pvh_boot);
+        DECLARE_IMPORT(pvh_start_info_pa);
         . = . + GAP;
         *(.text)
         *(.text.*)
diff --git a/xen/arch/x86/boot/head.S b/xen/arch/x86/boot/head.S
index dcda91cfda..f86910294f 100644
--- a/xen/arch/x86/boot/head.S
+++ b/xen/arch/x86/boot/head.S
@@ -515,16 +515,6 @@ trampoline_setup:
         /*      reloc(magic/eax, info/edx) using fastcall. */
         call    reloc
 
-#ifdef CONFIG_PVH_GUEST
-        cmpb    $0, sym_esi(pvh_boot)
-        je      1f
-        mov     %eax, sym_esi(pvh_start_info_pa)
-        jmp     2f
-#endif
-1:
-        mov     %eax, sym_esi(multiboot_ptr)
-2:
-
         /*
          * Now trampoline_phys points to the following structure (lowest address
          * is at the bottom):
diff --git a/xen/arch/x86/boot/reloc.c b/xen/arch/x86/boot/reloc.c
index e50e161b27..a03ef71a4c 100644
--- a/xen/arch/x86/boot/reloc.c
+++ b/xen/arch/x86/boot/reloc.c
@@ -17,13 +17,15 @@
 #include <xen/types.h>
 
 #include <xen/kconfig.h>
-#include <xen/multiboot.h>
 #include <xen/multiboot2.h>
 #include <xen/page-size.h>
+#include <xen/bug.h>
 
 #include <asm/trampoline.h>
+#include <asm/setup.h>
 
 #include <public/arch-x86/hvm/start_info.h>
+#include <asm/guest/pvh-boot.h>
 
 #ifdef CONFIG_VIDEO
 # include "video.h"
@@ -347,28 +349,42 @@ static multiboot_info_t *mbi2_reloc(uint32_t mbi_in, memctx *ctx)
 }
 
 /* SAF-1-safe */
-void *reloc(uint32_t magic, uint32_t in)
+void reloc(uint32_t magic, uint32_t in)
 {
     /* Get bottom-most low-memory stack address. */
     memctx ctx = { trampoline_phys + TRAMPOLINE_SPACE };
 
+    void *res;
+
     switch ( magic )
     {
     case MULTIBOOT_BOOTLOADER_MAGIC:
-        return mbi_reloc(in, &ctx);
+        res = mbi_reloc(in, &ctx);
+        break;
 
     case MULTIBOOT2_BOOTLOADER_MAGIC:
-        return mbi2_reloc(in, &ctx);
+        res = mbi2_reloc(in, &ctx);
+        break;
 
     case XEN_HVM_START_MAGIC_VALUE:
         if ( IS_ENABLED(CONFIG_PVH_GUEST) )
-            return pvh_info_reloc(in, &ctx);
+        {
+            res = pvh_info_reloc(in, &ctx);
+            break;
+        }
         /* Fallthrough */
 
     default:
         /* Nothing we can do */
-        return NULL;
+        res = NULL;
     }
+
+#ifdef CONFIG_PVH_GUEST
+    if ( pvh_boot )
+        pvh_start_info_pa = (unsigned long)res;
+#endif
+
+    multiboot_ptr = (unsigned long)res;
 }
 
 /*
diff --git a/xen/arch/x86/include/asm/guest/pvh-boot.h b/xen/arch/x86/include/asm/guest/pvh-boot.h
index 247ba6899e..b5ad2b11a4 100644
--- a/xen/arch/x86/include/asm/guest/pvh-boot.h
+++ b/xen/arch/x86/include/asm/guest/pvh-boot.h
@@ -13,6 +13,7 @@
 #ifdef CONFIG_PVH_GUEST
 
 extern bool pvh_boot;
+extern uint32_t pvh_start_info_pa;
 
 void pvh_init(multiboot_info_t **mbi, module_t **mod);
 void pvh_print_info(void);
-- 
2.34.1