mini-os: don't assume contiguous RAM when initializing in PVH mode

Sizing the available memory should respect memory holes, so look at
the memory map when setting the boundary for the memory allocator.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>

diff --git a/arch/x86/mm.c b/arch/x86/mm.c
index 8df93daadad6303891ac527d7f3b931f8d9b366d..3bf6170a4543d712f2d03732232ab5cb351c448c 100644 (file)
--- a/arch/x86/mm.c
+++ b/arch/x86/mm.c
@@ -107,7 +107,6 @@ void arch_mm_preinit(void *p)
 {
     long ret;
     domid_t domid = DOMID_SELF;
-    unsigned long max;
 
     pt_base = page_table_base;
     first_free_pfn = PFN_UP(to_phys(&_end));
@@ -117,11 +116,8 @@ void arch_mm_preinit(void *p)
         xprintk("could not get memory size\n");
         do_exit();
     }
-    last_free_pfn = ret;
 
-    max = e820_get_maxpfn();
-    if ( max < last_free_pfn )
-        last_free_pfn = max;
+    last_free_pfn = e820_get_maxpfn(ret);
 }
 #endif
 

diff --git a/e820.c b/e820.c
index 70286cb8094704bbee34aed7165f6d3336937422..4c726d1f3879b2975a1de42eaf9705032ff62015 100644 (file)
--- a/e820.c
+++ b/e820.c
@@ -285,10 +285,10 @@ void arch_print_memmap(void)
 }
 #endif
 
-unsigned long e820_get_maxpfn(void)
+unsigned long e820_get_maxpfn(unsigned long pages)
 {
     int i;
-    unsigned long pfn, max = 0;
+    unsigned long pfns = 0, start = 0;
 
     e820_get_memmap();
 
@@ -296,10 +296,12 @@ unsigned long e820_get_maxpfn(void)
     {
         if ( e820_map[i].type != E820_RAM )
             continue;
-        pfn = (e820_map[i].addr + e820_map[i].size) >> PAGE_SHIFT;
-        if ( pfn > max )
-            max = pfn;
+        pfns = e820_map[i].size >> PAGE_SHIFT;
+        start = e820_map[i].addr >> PAGE_SHIFT;
+        if ( pages <= pfns )
+            return start + pages;
+        pages -= pfns;
     }
 
-    return max;
+    return start + pfns;
 }

diff --git a/include/e820.h b/include/e820.h
index af2129fec22d311766fe9846366c3fdb2844d871..6a57f05ec28f6a098fd7ce52c601ea2ff6a0a71f 100644 (file)
--- a/include/e820.h
+++ b/include/e820.h
@@ -49,6 +49,6 @@ struct __packed e820entry {
 extern struct e820entry e820_map[];
 extern unsigned e820_entries;
 
-unsigned long e820_get_maxpfn(void);
+unsigned long e820_get_maxpfn(unsigned long pages);
 
 #endif /*__E820_HEADER*/