guest/pvh: fix handling of multiboot module list

When booting Xen as a PVH guest the data in the PVH start info
structure is copied over to a multiboot structure and a module list
array that resides in the .init section of the Xen image. The
resulting multiboot module list is then handed to the generic boot
process using the physical address in mbi->mods_addr.

This works fine as long as the Xen image doesn't relocate itself, if
there's such a relocation the physical addresses of multiboot module
list is no longer valid.

Fix this by handing the virtual address of the module list to the
generic boot process instead of it's physical address.

Reported-by: Sergey Dyasli <sergey.dyasli@citrix.com>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>

diff --git a/xen/arch/x86/guest/pvh-boot.c b/xen/arch/x86/guest/pvh-boot.c
index 6e81b32b92b04e534072c1a041bcbe6371062e84..544775eeb42b3e21119fd6df4a321f331bf6a4b1 100644 (file)
--- a/xen/arch/x86/guest/pvh-boot.c
+++ b/xen/arch/x86/guest/pvh-boot.c
@@ -35,11 +35,11 @@ static multiboot_info_t __initdata pvh_mbi;
 static module_t __initdata pvh_mbi_mods[8];
 static const char *__initdata pvh_loader = "PVH Directboot";
 
-static void __init convert_pvh_info(void)
+static void __init convert_pvh_info(multiboot_info_t **mbi,
+                                    module_t **mod)
 {
     const struct hvm_start_info *pvh_info = __va(pvh_start_info_pa);
     const struct hvm_modlist_entry *entry;
-    module_t *mod;
     unsigned int i;
 
     if ( pvh_info->magic != XEN_HVM_START_MAGIC_VALUE )
@@ -68,20 +68,22 @@ static void __init convert_pvh_info(void)
     pvh_mbi.mods_count = pvh_info->nr_modules;
     pvh_mbi.mods_addr = __pa(pvh_mbi_mods);
 
-    mod = pvh_mbi_mods;
     entry = __va(pvh_info->modlist_paddr);
     for ( i = 0; i < pvh_info->nr_modules; i++ )
     {
         BUG_ON(entry[i].paddr >> 32);
         BUG_ON(entry[i].cmdline_paddr >> 32);
 
-        mod[i].mod_start = entry[i].paddr;
-        mod[i].mod_end   = entry[i].paddr + entry[i].size;
-        mod[i].string    = entry[i].cmdline_paddr;
+        pvh_mbi_mods[i].mod_start = entry[i].paddr;
+        pvh_mbi_mods[i].mod_end   = entry[i].paddr + entry[i].size;
+        pvh_mbi_mods[i].string    = entry[i].cmdline_paddr;
     }
 
     BUG_ON(!pvh_info->rsdp_paddr);
     rsdp_hint = pvh_info->rsdp_paddr;
+
+    *mbi = &pvh_mbi;
+    *mod = pvh_mbi_mods;
 }
 
 static void __init get_memory_map(void)
@@ -98,16 +100,14 @@ static void __init get_memory_map(void)
     sanitize_e820_map(e820_raw.map, &e820_raw.nr_map);
 }
 
-multiboot_info_t *__init pvh_init(void)
+void __init pvh_init(multiboot_info_t **mbi, module_t **mod)
 {
-    convert_pvh_info();
+    convert_pvh_info(mbi, mod);
 
     probe_hypervisor();
     ASSERT(xen_guest);
 
     get_memory_map();
-
-    return &pvh_mbi;
 }
 
 void __init pvh_print_info(void)

diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
index 55a288f332b511d71860f83f5ef2b57c4f76ed3b..9cbff22fb36350f461bd85beb425bfb2b7ec74a7 100644 (file)
--- a/xen/arch/x86/setup.c
+++ b/xen/arch/x86/setup.c
@@ -719,12 +719,13 @@ void __init noreturn __start_xen(unsigned long mbi_p)
          */
         opt_console_xen = -1;
         ASSERT(mbi_p == 0);
-        mbi = pvh_init();
+        pvh_init(&mbi, &mod);
     }
     else
+    {
         mbi = __va(mbi_p);
-
-    mod = __va(mbi->mods_addr);
+        mod = __va(mbi->mods_addr);
+    }
 
     loader = (mbi->flags & MBI_LOADERNAME)
         ? (char *)__va(mbi->boot_loader_name) : "unknown";

diff --git a/xen/include/asm-x86/guest/pvh-boot.h b/xen/include/asm-x86/guest/pvh-boot.h
index 1b429f9401d4a11ead8a8bf727fb882121672086..b8a76c4eed9a8d994dca3f453d32d457b3360954 100644 (file)
--- a/xen/include/asm-x86/guest/pvh-boot.h
+++ b/xen/include/asm-x86/guest/pvh-boot.h
@@ -25,17 +25,16 @@
 
 extern bool pvh_boot;
 
-multiboot_info_t *pvh_init(void);
+void pvh_init(multiboot_info_t **mbi, module_t **mod);
 void pvh_print_info(void);
 
 #else
 
 #define pvh_boot 0
 
-static inline multiboot_info_t *pvh_init(void)
+static inline void pvh_init(multiboot_info_t **mbi, module_t **mod)
 {
     ASSERT_UNREACHABLE();
-    return NULL;
 }
 
 static inline void pvh_print_info(void)