[Qemu-devel] [PATCH V2 4/5] xen: Change memory access behavior during migration.

[Anthony PERARD <anthony.perard@citrix.com>]

Do not allocate RAM during pre-migration runstate.
Do not actually "do" set_memory during migration.

Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
---
 xen-all.c |   13 +++++++++++++
 1 files changed, 13 insertions(+), 0 deletions(-)

diff --git a/xen-all.c b/xen-all.c
index b2e9853..c1fed87 100644
--- a/xen-all.c
+++ b/xen-all.c
@@ -189,6 +189,11 @@ void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size)
 
     trace_xen_ram_alloc(ram_addr, size);
 
+    if (runstate_check(RUN_STATE_PREMIGRATE)) {
+        /* RAM already populated in Xen */
+        return;
+    }
+
     nr_pfn = size >> TARGET_PAGE_BITS;
     pfn_list = g_malloc(sizeof (*pfn_list) * nr_pfn);
 
@@ -269,6 +274,13 @@ go_physmap:
     DPRINTF("mapping vram to %llx - %llx, from %llx\n",
             start_addr, start_addr + size, phys_offset);
 
+    if (runstate_check(RUN_STATE_INMIGRATE)) {
+        /* The mapping should already be done and can not be done a second
+         * time. So we just add to the physmap list instead.
+         */
+        goto done;
+    }
+
     pfn = phys_offset >> TARGET_PAGE_BITS;
     start_gpfn = start_addr >> TARGET_PAGE_BITS;
     for (i = 0; i < size >> TARGET_PAGE_BITS; i++) {
@@ -283,6 +295,7 @@ go_physmap:
         }
     }
 
+done:
     physmap = g_malloc(sizeof (XenPhysmap));
 
     physmap->start_addr = start_addr;
-- 
Anthony PERARD