x86/layout: Correct Xen's idea of its own memory layout

c/s b4cd59fe "x86: reorder .data and .init when linking" had an unintended
side effect, where xen_in_range() and the tboot S3 MAC were no longer correct.

In practice, it means that Xen's .data section is excluded from consideration,
which means:
 1) Default IOMMU construction for the hardware domain could create mappings.
 2) .data isn't included in the tboot MAC checked on resume from S3.

Adjust the comments and virtual address anchors used to define the regions.

Reported-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
master commit: c9a4a1c419cebac83a8fb60c4532ad8ccc973dc4
master date: 2017-02-28 16:18:38 +0000

diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
index b13067132d29d7eeecee1eac08f3b6a327d9a177..8dbf36c7e4504c5089ff52e89c9b4ba6499713ef 100644 (file)
--- a/xen/arch/x86/setup.c
+++ b/xen/arch/x86/setup.c
@@ -1672,7 +1672,7 @@ int __hwdom_init xen_in_range(unsigned long mfn)
     paddr_t start, end;
     int i;
 
-    enum { region_s3, region_text, region_bss, nr_regions };
+    enum { region_s3, region_ro, region_rw, nr_regions };
     static struct {
         paddr_t s, e;
     } xen_regions[nr_regions] __hwdom_initdata;
@@ -1683,12 +1683,12 @@ int __hwdom_init xen_in_range(unsigned long mfn)
         /* S3 resume code (and other real mode trampoline code) */
         xen_regions[region_s3].s = bootsym_phys(trampoline_start);
         xen_regions[region_s3].e = bootsym_phys(trampoline_end);
-        /* hypervisor code + data */
-        xen_regions[region_text].s =__pa(&_stext);
-        xen_regions[region_text].e = __pa(&__init_begin);
-        /* bss */
-        xen_regions[region_bss].s = __pa(&__bss_start);
-        xen_regions[region_bss].e = __pa(&__bss_end);
+        /* hypervisor .text + .rodata */
+        xen_regions[region_ro].s = __pa(&_stext);
+        xen_regions[region_ro].e = __pa(&__2M_rodata_end);
+        /* hypervisor .data + .bss */
+        xen_regions[region_rw].s = __pa(&__2M_rwdata_start);
+        xen_regions[region_rw].e = __pa(&__2M_rwdata_end);
     }
 
     start = (paddr_t)mfn << PAGE_SHIFT;

diff --git a/xen/arch/x86/tboot.c b/xen/arch/x86/tboot.c
index e5d7c42e84ceb8d8f7d7afc75c023670be3bb452..3c00cfc21bb622a1ef3077d34b9541bf08b40b27 100644 (file)
--- a/xen/arch/x86/tboot.c
+++ b/xen/arch/x86/tboot.c
@@ -12,6 +12,7 @@
 #include <asm/processor.h>
 #include <asm/e820.h>
 #include <asm/tboot.h>
+#include <asm/setup.h>
 #include <crypto/vmac.h>
 
 /* tboot=<physical address of shared page> */
@@ -370,13 +371,14 @@ void tboot_shutdown(uint32_t shutdown_type)
         g_tboot_shared->mac_regions[0].start = bootsym_phys(trampoline_start);
         g_tboot_shared->mac_regions[0].size = bootsym_phys(trampoline_end) -
                                               bootsym_phys(trampoline_start);
-        /* hypervisor code + data */
+        /* hypervisor .text + .rodata */
         g_tboot_shared->mac_regions[1].start = (uint64_t)__pa(&_stext);
-        g_tboot_shared->mac_regions[1].size = __pa(&__init_begin) -
+        g_tboot_shared->mac_regions[1].size = __pa(&__2M_rodata_end) -
                                               __pa(&_stext);
-        /* bss */
-        g_tboot_shared->mac_regions[2].start = (uint64_t)__pa(&__bss_start);
-        g_tboot_shared->mac_regions[2].size = __pa(&__bss_end) - __pa(&__bss_start);
+        /* hypervisor .data + .bss */
+        g_tboot_shared->mac_regions[2].start = (uint64_t)__pa(&__2M_rwdata_start);
+        g_tboot_shared->mac_regions[2].size = __pa(&__2M_rwdata_end) -
+                                              __pa(&__2M_rwdata_start);
 
         /*
          * MAC domains and other Xen memory