memguard: drop memguard_init() entirely

The use of MAP_SMALL_PAGES causes shattering of the superpages making up the
Xen virtual region, and is counter to the purpose of this series.
Furthermore, it is not required for the memguard infrastructure to function
(which itself uses map_pages_to_xen() for creating holes).

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <JBeulich@suse.com>
Acked-by: Stefano Stabellini <stefano.stabellini@citrix.com>

diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index d6aaed81adca4401c117be91910366c31d9c9e5c..ed8ab0282ca7111623693250335fe36918a51c6f 100644 (file)
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -6346,22 +6346,6 @@ void free_perdomain_mappings(struct domain *d)
 
 #ifdef MEMORY_GUARD
 
-void memguard_init(void)
-{
-    unsigned long start = max_t(unsigned long, xen_phys_start, 1UL << 20);
-    map_pages_to_xen(
-        (unsigned long)__va(start),
-        start >> PAGE_SHIFT,
-        (__pa(&_end) + PAGE_SIZE - 1 - start) >> PAGE_SHIFT,
-        __PAGE_HYPERVISOR_RW|MAP_SMALL_PAGES);
-    BUG_ON(start != xen_phys_start);
-    map_pages_to_xen(
-        XEN_VIRT_START,
-        start >> PAGE_SHIFT,
-        (__pa(&_end) + PAGE_SIZE - 1 - start) >> PAGE_SHIFT,
-        __PAGE_HYPERVISOR|MAP_SMALL_PAGES);
-}
-
 static void __memguard_change_range(void *p, unsigned long l, int guard)
 {
     unsigned long _p = (unsigned long)p;

diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
index b8a28d7dcafc932093c46dee034f8e4438ab4adb..cddf954c7120e9f70667b108f15bf3a03e780293 100644 (file)
--- a/xen/arch/x86/setup.c
+++ b/xen/arch/x86/setup.c
@@ -1146,8 +1146,6 @@ void __init noreturn __start_xen(unsigned long mbi_p)
                    ~((1UL << L2_PAGETABLE_SHIFT) - 1);
     destroy_xen_mappings(xen_virt_end, XEN_VIRT_START + BOOTSTRAP_MAP_BASE);
 
-    memguard_init();
-
     nr_pages = 0;
     for ( i = 0; i < e820.nr_map; i++ )
         if ( e820.map[i].type == E820_RAM )

diff --git a/xen/include/asm-arm/mm.h b/xen/include/asm-arm/mm.h
index 2e9d0b2286068786561e6c3fd1b992f8d186be97..68cf203c12b01807168080fe60c3186b5e004056 100644 (file)
--- a/xen/include/asm-arm/mm.h
+++ b/xen/include/asm-arm/mm.h
@@ -331,7 +331,6 @@ unsigned long domain_get_maximum_gpfn(struct domain *d);
 
 extern struct domain *dom_xen, *dom_io, *dom_cow;
 
-#define memguard_init(_s)              (_s)
 #define memguard_guard_stack(_p)       ((void)0)
 #define memguard_guard_range(_p,_l)    ((void)0)
 #define memguard_unguard_range(_p,_l)  ((void)0)

diff --git a/xen/include/asm-x86/mm.h b/xen/include/asm-x86/mm.h
index a09738265768ff36d848abd4934f5633aafed7e6..23a40922202b8e0e74d03d763e756184629fa20b 100644 (file)
--- a/xen/include/asm-x86/mm.h
+++ b/xen/include/asm-x86/mm.h
@@ -479,11 +479,9 @@ extern struct rangeset *mmio_ro_ranges;
 #define compat_cr3_to_pfn(cr3) (((unsigned)(cr3) >> 12) | ((unsigned)(cr3) << 20))
 
 #ifdef MEMORY_GUARD
-void memguard_init(void);
 void memguard_guard_range(void *p, unsigned long l);
 void memguard_unguard_range(void *p, unsigned long l);
 #else
-#define memguard_init()                ((void)0)
 #define memguard_guard_range(_p,_l)    ((void)0)
 #define memguard_unguard_range(_p,_l)  ((void)0)
 #endif