x86: relocate pvh_info

Modify early boot code to relocate pvh info as well, so that we can be
sure __va in __start_xen works.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>

xen/arch/x86/boot/Makefile

@@ -5,7 +5,8 @@ DEFS_H_DEPS = defs.h $(BASEDIR)/include/xen/stdbool.h
 CMDLINE_DEPS = $(DEFS_H_DEPS) video.h
 
 RELOC_DEPS = $(DEFS_H_DEPS) $(BASEDIR)/include/xen/multiboot.h \
-	     $(BASEDIR)/include/xen/multiboot2.h
+	     $(BASEDIR)/include/xen/multiboot2.h \
+	     $(BASEDIR)/include/public/arch-x86/hvm/start_info.h
 
 head.o: cmdline.S reloc.S
 

xen/arch/x86/boot/defs.h

@@ -51,6 +51,9 @@ typedef unsigned short u16;
 typedef unsigned int u32;
 typedef unsigned long long u64;
 typedef unsigned int size_t;
+typedef u8 uint8_t;
+typedef u32 uint32_t;
+typedef u64 uint64_t;
 
 #define U16_MAX		((u16)(~0U))
 #define UINT_MAX	(~0U)

xen/arch/x86/boot/head.S

@@ -414,6 +414,7 @@ __pvh_start:
 
         /* Set trampoline_phys to use mfn 1 to avoid having a mapping at VA 0 */
         movw    $0x1000, sym_esi(trampoline_phys)
+        mov     (%ebx), %eax /* mov $XEN_HVM_START_MAGIC_VALUE, %eax */
         jmp     trampoline_setup
 
 #endif /* CONFIG_PVH_GUEST */
@@ -578,18 +579,20 @@ trampoline_setup:
         /* Get bottom-most low-memory stack address. */
         add     $TRAMPOLINE_SPACE,%ecx
 
-#ifdef CONFIG_PVH_GUEST
-        cmpb    $0, sym_fs(pvh_boot)
-        jne     1f
-#endif
-
-        /* Save the Multiboot info struct (after relocation) for later use. */
+        /* Save Multiboot / PVH info struct (after relocation) for later use. */
         push    %ecx                /* Bottom-most low-memory stack address. */
-        push    %ebx                /* Multiboot information address. */
-        push    %eax                /* Multiboot magic. */
+        push    %ebx                /* Multiboot / PVH information address. */
+        push    %eax                /* Magic number. */
         call    reloc
-        mov     %eax,sym_fs(multiboot_ptr)
+#ifdef CONFIG_PVH_GUEST
+        cmp     $0, sym_fs(pvh_boot)
+        je      1f
+        mov     %eax, sym_fs(pvh_start_info_pa)
+        jmp     2f
+#endif
 1:
+        mov     %eax, sym_fs(multiboot_ptr)
+2:
 
         /*
          * Now trampoline_phys points to the following structure (lowest address
@@ -598,12 +601,12 @@ trampoline_setup:
          * +------------------------+
          * | TRAMPOLINE_STACK_SPACE |
          * +------------------------+
-         * |        mbi data        |
+         * |     Data (MBI / PVH)   |
          * +- - - - - - - - - - - - +
          * |    TRAMPOLINE_SPACE    |
          * +------------------------+
          *
-         * mbi data grows downwards from the highest address of TRAMPOLINE_SPACE
+         * Data grows downwards from the highest address of TRAMPOLINE_SPACE
          * region to the end of the trampoline. The rest of TRAMPOLINE_SPACE is
          * reserved for trampoline code and data.
          */

xen/arch/x86/boot/reloc.c

@@ -14,8 +14,8 @@
 
 /*
  * This entry point is entered from xen/arch/x86/boot/head.S with:
- *   - 0x4(%esp) = MULTIBOOT_MAGIC,
- *   - 0x8(%esp) = MULTIBOOT_INFORMATION_ADDRESS,
+ *   - 0x4(%esp) = MAGIC,
+ *   - 0x8(%esp) = INFORMATION_ADDRESS,
  *   - 0xc(%esp) = TOPMOST_LOW_MEMORY_STACK_ADDRESS.
  */
 asm (
@@ -29,6 +29,9 @@ asm (
 #include "../../../include/xen/multiboot.h"
 #include "../../../include/xen/multiboot2.h"
 
+#include "../../../include/xen/kconfig.h"
+#include <public/arch-x86/hvm/start_info.h>
+
 #define get_mb2_data(tag, type, member)   (((multiboot2_tag_##type##_t *)(tag))->member)
 #define get_mb2_string(tag, type, member) ((u32)get_mb2_data(tag, type, member))
 
@@ -71,6 +74,36 @@ static u32 copy_string(u32 src)
     return copy_mem(src, p - src + 1);
 }
 
+static struct hvm_start_info *pvh_info_reloc(u32 in)
+{
+    struct hvm_start_info *out;
+
+    out = _p(copy_mem(in, sizeof(*out)));
+
+    if ( out->cmdline_paddr )
+        out->cmdline_paddr = copy_string(out->cmdline_paddr);
+
+    if ( out->nr_modules )
+    {
+        unsigned int i;
+        struct hvm_modlist_entry *mods;
+
+        out->modlist_paddr =
+            copy_mem(out->modlist_paddr,
+                     out->nr_modules * sizeof(struct hvm_modlist_entry));
+
+        mods = _p(out->modlist_paddr);
+
+        for ( i = 0; i < out->nr_modules; i++ )
+        {
+            if ( mods[i].cmdline_paddr )
+                mods[i].cmdline_paddr = copy_string(mods[i].cmdline_paddr);
+        }
+    }
+
+    return out;
+}
+
 static multiboot_info_t *mbi_reloc(u32 mbi_in)
 {
     int i;
@@ -226,14 +259,27 @@ static multiboot_info_t *mbi2_reloc(u32 mbi_in)
     return mbi_out;
 }
 
-multiboot_info_t __stdcall *reloc(u32 mb_magic, u32 mbi_in, u32 trampoline)
+void * __stdcall reloc(u32 magic, u32 in, u32 trampoline)
 {
     alloc = trampoline;
 
-    if ( mb_magic == MULTIBOOT2_BOOTLOADER_MAGIC )
-        return mbi2_reloc(mbi_in);
-    else
-        return mbi_reloc(mbi_in);
+    switch ( magic )
+    {
+    case MULTIBOOT_BOOTLOADER_MAGIC:
+        return mbi_reloc(in);
+
+    case MULTIBOOT2_BOOTLOADER_MAGIC:
+        return mbi2_reloc(in);
+
+    case XEN_HVM_START_MAGIC_VALUE:
+        if ( IS_ENABLED(CONFIG_PVH_GUEST) )
+            return pvh_info_reloc(in);
+        /* Fallthrough */
+
+    default:
+        /* Nothing we can do */
+        return NULL;
+    }
 }
 
 /*