[Xen-changelog] [xen stable-4.8] x86/EFI: avoid Xen image when looking for module/kexec position

[patchbot@xxxxxxx]

commit c95bad938f77a863f46bbce6cad74012714776bb
Author:     Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Fri Mar 31 08:32:51 2017 +0200
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Fri Mar 31 08:32:51 2017 +0200

    x86/EFI: avoid Xen image when looking for module/kexec position
    
    When booting straight from EFI, we don't further try to relocate Xen.
    As a result, so far we also didn't avoid the area Xen uses when looking
    for a location to put modules or the kexec area. Introduce a fake
    module slot to deal with that without having to fiddle with a lot of
    code.
    
    Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
    Reviewed-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
    master commit: e22e1c47958a4778cd7baa3980f74e52f525ba28
    master date: 2017-03-20 09:27:12 +0100
---
 xen/arch/x86/efi/efi-boot.h |  6 +++++-
 xen/arch/x86/setup.c        | 22 +++++++++++++++++-----
 2 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/xen/arch/x86/efi/efi-boot.h b/xen/arch/x86/efi/efi-boot.h
index 637310d..d11b9c4 100644
--- a/xen/arch/x86/efi/efi-boot.h
+++ b/xen/arch/x86/efi/efi-boot.h
@@ -13,7 +13,11 @@ static struct file __initdata ucode;
 static multiboot_info_t __initdata mbi = {
     .flags = MBI_MODULES | MBI_LOADERNAME
 };
-static module_t __initdata mb_modules[4];
+/*
+ * The array size needs to be one larger than the number of modules we
+ * support - see __start_xen().
+ */
+static module_t __initdata mb_modules[5];
 
 static void __init edd_put_string(u8 *dst, size_t n, const char *src)
 {
diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
index 10e846f..1bfe4ce 100644
--- a/xen/arch/x86/setup.c
+++ b/xen/arch/x86/setup.c
@@ -890,6 +890,17 @@ void __init noreturn __start_xen(unsigned long mbi_p)
         mod[i].reserved = 0;
     }
 
+    if ( efi_enabled )
+    {
+        /*
+         * This needs to remain in sync with xen_in_range() and the
+         * respective reserve_e820_ram() invocation below.
+         */
+        mod[mbi->mods_count].mod_start = PFN_DOWN(mbi->mem_upper);
+        mod[mbi->mods_count].mod_end = __pa(__2M_rwdata_end) -
+                                       (mbi->mem_upper & PAGE_MASK);
+    }
+
     modules_headroom = bzimage_headroom(bootstrap_map(mod), mod->mod_end);
     bootstrap_map(NULL);
 
@@ -1070,8 +1081,9 @@ void __init noreturn __start_xen(unsigned long mbi_p)
             if ( mod[j].reserved )
                 continue;
 
-            /* Don't overlap with other modules. */
-            end = consider_modules(s, e, size, mod, mbi->mods_count, j);
+            /* Don't overlap with other modules (or Xen itself). */
+            end = consider_modules(s, e, size, mod,
+                                   mbi->mods_count + efi_enabled, j);
 
             if ( highmem_start && end > highmem_start )
                 continue;
@@ -1096,9 +1108,9 @@ void __init noreturn __start_xen(unsigned long mbi_p)
          */
         while ( !kexec_crash_area.start )
         {
-            /* Don't overlap with modules. */
-            e = consider_modules(s, e, PAGE_ALIGN(kexec_crash_area.size),
-                                 mod, mbi->mods_count, -1);
+            /* Don't overlap with modules (or Xen itself). */
+            e = consider_modules(s, e, PAGE_ALIGN(kexec_crash_area.size), mod,
+                                 mbi->mods_count + efi_enabled, -1);
             if ( s >= e )
                 break;
             if ( e > kexec_crash_area_limit )
--
generated by git-patchbot for /home/xen/git/xen.git#stable-4.8

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