# HG changeset patch
# User gcosta@redhat.com
# Date 1164380458 18000
# Node ID da7aa8896ab07932160406c8b19a6ad4a61b3af7
# Parent  47fcd5f768fef50cba2fc6dbadc7b75de55e88a5
[XEN] Implement the memory_map hypercall

It's needed to provide guests with an idea of a physical
mapping that may differ from simply what's needed to fit
tot_pages.

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>

diff -r 47fcd5f768fe -r da7aa8896ab0 xen/arch/x86/mm.c
--- a/xen/arch/x86/mm.c	Fri Nov 17 08:30:43 2006 -0500
+++ b/xen/arch/x86/mm.c	Fri Nov 24 10:00:58 2006 -0500
@@ -2976,7 +2976,45 @@ long arch_memory_op(int op, XEN_GUEST_HA
 
     case XENMEM_memory_map:
     {
-        return -ENOSYS;
+        struct xen_memory_map memmap;
+        struct domain *d;
+        XEN_GUEST_HANDLE(e820entry_t) buffer;
+        struct e820entry map;
+    
+        if ( IS_PRIV(current->domain) )
+            return -ENOSYS;
+
+        d = current->domain;
+
+        if ( copy_from_guest(&memmap, arg, 1) )
+            return -EFAULT;
+
+        buffer = guest_handle_cast(memmap.buffer, e820entry_t);
+        if ( unlikely(guest_handle_is_null(buffer)) ) 
+            return -EFAULT;
+
+        memmap.nr_entries = 1;
+
+        /* if we were not supplied with proper information, the best we can 
+         * do is rely on the current max_pages information as a sane bound */ 
+        if (d->memory_map_limit)
+            map.size = d->memory_map_limit;
+        else
+            map.size = d->max_pages << PAGE_SHIFT;
+
+        /* 8MB slack (to balance backend allocations). */
+        map.size += 8 << 20;
+        map.addr = 0ULL;
+        map.type = E820_RAM;
+
+        if ( copy_to_guest(arg, &memmap, 1) )
+            return -EFAULT;
+
+        if ( copy_to_guest(buffer, &map, 1) < 0 )
+            return -EFAULT;
+
+        return 0;
+
     }
 
     case XENMEM_machine_memory_map: