[PATCH v2] txt: 3/5 - explicitly protect TXT addr ranges from dom0

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[PATCH v2] txt: 3/5 - explicitly protect TXT addr ranges from dom0

Cihula, Joseph
tboot no longer marks the TXT heap/SINIT/private config space as E820_UNUSABLE in the e820 table, so Xen must explicitly disallow those regions from dom0.

Signed-off-by: Shane Wang <[hidden email]>
Signed-off-by: Joseph Cihula <[hidden email]>

diff -r 9ba8aecc3a15 -r 196ed4d1e316 xen/arch/x86/e820.c
--- a/xen/arch/x86/e820.c       Wed Jan 28 22:09:02 2009 -0800
+++ b/xen/arch/x86/e820.c       Wed Jan 28 22:12:49 2009 -0800
@@ -391,11 +391,14 @@ static void __init machine_specific_memo
     reserve_dmi_region();
 }

-/* Reserve RAM area (@s,@e) in the specified e820 map. */
-int __init reserve_e820_ram(struct e820map *e820, uint64_t s, uint64_t e)
+static int reserve_e820(struct e820map *e820, uint64_t s, uint64_t e,
+                       uint32_t orig_type, uint32_t new_type)
 {
     uint64_t rs = 0, re = 0;
-    int i;
+    int i, remove;
+
+    /* if reserving region, can delete instead */
+    remove = (new_type == E820_RESERVED);

     for ( i = 0; i < e820->nr_map; i++ )
     {
@@ -406,37 +409,89 @@ int __init reserve_e820_ram(struct e820m
             break;
     }

-    if ( (i == e820->nr_map) || (e820->map[i].type != E820_RAM) )
+    if ( (i == e820->nr_map) || (e820->map[i].type != orig_type) )
         return 0;

     if ( (s == rs) && (e == re) )
     {
         /* Complete excision. */
-        memmove(&e820->map[i], &e820->map[i+1],
-                (e820->nr_map-i-1) * sizeof(e820->map[0]));
-        e820->nr_map--;
+        if ( remove )
+        {
+            memmove(&e820->map[i], &e820->map[i+1],
+                    (e820->nr_map-i-1) * sizeof(e820->map[0]));
+            e820->nr_map--;
+        }
+        else
+            e820->map[i].type = new_type;
     }
     else if ( s == rs )
     {
-        /* Truncate start. */
+        /* Truncate start or split. */
+        if ( !remove )
+        {
+           /* split */
+            if ( e820->nr_map+1 > ARRAY_SIZE(e820->map) )
+            {
+                printk("e820 overflow\n");
+                return 0;
+            }
+            memmove(&e820->map[i+1], &e820->map[i],
+                    (e820->nr_map-i) * sizeof(e820->map[0]));
+            e820->nr_map++;
+            e820->map[i].addr = s;
+            e820->map[i].size = e - s;
+            e820->map[i].type = new_type;
+            i++;
+        }
         e820->map[i].addr += e - s;
         e820->map[i].size -= e - s;
     }
     else if ( e == re )
     {
-        /* Truncate end. */
+        /* Truncate end or split. */
+        if ( !remove )
+        {
+            if ( e820->nr_map+1 > ARRAY_SIZE(e820->map) )
+            {
+                printk("e820 overflow\n");
+                return 0;
+            }
+            memmove(&e820->map[i+1], &e820->map[i],
+                    (e820->nr_map-i) * sizeof(e820->map[0]));
+            e820->nr_map++;
+            e820->map[i+1].addr = s;
+            e820->map[i+1].size = e - s;
+            e820->map[i+1].type = new_type;
+        }
         e820->map[i].size -= e - s;
     }
-    else if ( e820->nr_map < ARRAY_SIZE(e820->map) )
+    else if ( e820->nr_map+1 < ARRAY_SIZE(e820->map) )
     {
-        /* Split in two. */
-        memmove(&e820->map[i+1], &e820->map[i],
-                (e820->nr_map-i) * sizeof(e820->map[0]));
-        e820->nr_map++;
-        e820->map[i].size = s - rs;
-        i++;
-        e820->map[i].addr = e;
-        e820->map[i].size = re - e;
+        /* Split in two or three. */
+        if ( !remove )
+        {
+            memmove(&e820->map[i+2], &e820->map[i],
+                    (e820->nr_map-i) * sizeof(e820->map[0]));
+            e820->nr_map += 2;
+            e820->map[i].size = s - rs;
+            i++;
+            e820->map[i].addr = s;
+            e820->map[i].size = e - s;
+            e820->map[i].type = new_type;
+            i++;
+            e820->map[i].addr = e;
+            e820->map[i].size = re - e;
+        }
+        else
+        {
+            memmove(&e820->map[i+1], &e820->map[i],
+                    (e820->nr_map-i) * sizeof(e820->map[0]));
+            e820->nr_map++;
+            e820->map[i].size = s - rs;
+            i++;
+            e820->map[i].addr = e;
+            e820->map[i].size = re - e;
+        }
     }
     else
     {
@@ -457,6 +512,18 @@ int __init reserve_e820_ram(struct e820m
     return 1;
 }

+/* Set E820_RAM area (@s,@e) as RESERVED (or delete) in specified e820 map. */
+int __init reserve_e820_ram(struct e820map *e820, uint64_t s, uint64_t e)
+{
+    return reserve_e820(e820, s, e, E820_RAM, E820_RESERVED);
+}
+
+/* Set E820_RESERVED area (@s, @e) as UNUSABLE in specified e820 map. */
+int reserve_e820_unusable(struct e820map *e820, uint64_t s, uint64_t e)
+{
+    return reserve_e820(e820, s, e, E820_RESERVED, E820_UNUSABLE);
+}
+
 unsigned long __init init_e820(
     const char *str, struct e820entry *raw, int *raw_nr)
 {
diff -r 9ba8aecc3a15 -r 196ed4d1e316 xen/arch/x86/setup.c
--- a/xen/arch/x86/setup.c      Wed Jan 28 22:09:02 2009 -0800
+++ b/xen/arch/x86/setup.c      Wed Jan 28 22:12:49 2009 -0800
@@ -1033,6 +1033,9 @@ void __init __start_xen(unsigned long mb
     if ( xen_cpuidle )
         xen_processor_pmbits |= XEN_PROCESSOR_PM_CX;

+    if ( !tboot_protect_mem_regions() )
+        panic("Could not protect TXT memory regions\n");
+
     /*
      * We're going to setup domain0 using the module(s) that we stashed safely
      * above our heap. The second module, if present, is an initrd ramdisk.
diff -r 9ba8aecc3a15 -r 196ed4d1e316 xen/arch/x86/tboot.c
--- a/xen/arch/x86/tboot.c      Wed Jan 28 22:09:02 2009 -0800
+++ b/xen/arch/x86/tboot.c      Wed Jan 28 22:12:49 2009 -0800
@@ -6,6 +6,7 @@
 #include <asm/fixmap.h>
 #include <asm/page.h>
 #include <asm/processor.h>
+#include <asm/e820.h>
 #include <asm/tboot.h>

 /* tboot=<physical address of shared page> */
@@ -16,6 +17,23 @@ tboot_shared_t *g_tboot_shared;
 tboot_shared_t *g_tboot_shared;

 static const uuid_t tboot_shared_uuid = TBOOT_SHARED_UUID;
+
+/*
+ * TXT configuration registers (offsets from TXT_{PUB, PRIV}_CONFIG_REGS_BASE)
+ */
+
+#define TXT_PUB_CONFIG_REGS_BASE       0xfed30000
+#define TXT_PRIV_CONFIG_REGS_BASE      0xfed20000
+
+/* # pages for each config regs space - used by fixmap */
+#define NR_TXT_CONFIG_PAGES     ((TXT_PUB_CONFIG_REGS_BASE -                \
+                                  TXT_PRIV_CONFIG_REGS_BASE) >> PAGE_SHIFT)
+
+/* offsets from pub/priv config space */
+#define TXTCR_SINIT_BASE            0x0270
+#define TXTCR_SINIT_SIZE            0x0278
+#define TXTCR_HEAP_BASE             0x0300
+#define TXTCR_HEAP_SIZE             0x0308

 void __init tboot_probe(void)
 {
@@ -84,6 +102,44 @@ int tboot_in_measured_env(void)
     return (g_tboot_shared != NULL);
 }

+int tboot_protect_mem_regions(void)
+{
+    uint64_t base, size;
+    uint32_t map_base, map_size;
+    unsigned long map_addr;
+
+    if ( !tboot_in_measured_env() )
+        return 1;
+
+    map_base = PFN_DOWN(TXT_PUB_CONFIG_REGS_BASE);
+    map_size = PFN_UP(NR_TXT_CONFIG_PAGES * PAGE_SIZE);
+    map_addr = (unsigned long)__va(map_base << PAGE_SHIFT);
+    if ( map_pages_to_xen(map_addr, map_base, map_size, __PAGE_HYPERVISOR) )
+        return 0;
+
+    /* TXT Heap */
+    base = *(uint64_t *)__va(TXT_PUB_CONFIG_REGS_BASE + TXTCR_HEAP_BASE);
+    size = *(uint64_t *)__va(TXT_PUB_CONFIG_REGS_BASE + TXTCR_HEAP_SIZE);
+    if ( !reserve_e820_unusable(&e820, base, base + size) )
+        return 0;
+
+    /* SINIT */
+    base = *(uint64_t *)__va(TXT_PUB_CONFIG_REGS_BASE + TXTCR_SINIT_BASE);
+    size = *(uint64_t *)__va(TXT_PUB_CONFIG_REGS_BASE + TXTCR_SINIT_SIZE);
+    if ( !reserve_e820_unusable(&e820, base, base + size) )
+        return 0;
+
+    /* TXT Private Space */
+    if ( !reserve_e820_unusable(&e820, TXT_PRIV_CONFIG_REGS_BASE,
+            TXT_PRIV_CONFIG_REGS_BASE + NR_TXT_CONFIG_PAGES * PAGE_SIZE) )
+        return 0;
+
+    destroy_xen_mappings((unsigned long)__va(map_base << PAGE_SHIFT),
+                         (unsigned long)__va((map_base + map_size) << PAGE_SHIFT));
+
+    return 1;
+}
+
 /*
  * Local variables:
  * mode: C
diff -r 9ba8aecc3a15 -r 196ed4d1e316 xen/include/asm-x86/e820.h
--- a/xen/include/asm-x86/e820.h        Wed Jan 28 22:09:02 2009 -0800
+++ b/xen/include/asm-x86/e820.h        Wed Jan 28 22:12:49 2009 -0800
@@ -24,6 +24,7 @@ struct e820map {
 };

 extern int reserve_e820_ram(struct e820map *e820, uint64_t s, uint64_t e);
+extern int reserve_e820_unusable(struct e820map *e820, uint64_t s, uint64_t e);
 extern unsigned long init_e820(const char *, struct e820entry *, int *);
 extern struct e820map e820;

diff -r 9ba8aecc3a15 -r 196ed4d1e316 xen/include/asm-x86/tboot.h
--- a/xen/include/asm-x86/tboot.h       Wed Jan 28 22:09:02 2009 -0800
+++ b/xen/include/asm-x86/tboot.h       Wed Jan 28 22:12:49 2009 -0800
@@ -100,6 +100,7 @@ void tboot_probe(void);
 void tboot_probe(void);
 void tboot_shutdown(uint32_t shutdown_type);
 int tboot_in_measured_env(void);
+int tboot_protect_mem_regions(void);

 #endif /* __TBOOT_H__ */


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