[PATCH for-4.6 v3] libxl: set stub domain size based on VRAM size

[Ian Jackson <ian.jackson@eu.citrix.com>]

From: Eric Shelton <eshelton@pobox.com>

Allocate additional memory to the stub domain for qemu-traditional if
more than 4 MB is assigned to the video adapter to avoid out of memory
condition for QEMU.

Signed-off-by: Eric Shelton <eshelton@pobox.com>
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
---
v3: Use max_t() instead
v2: Use max()
---
 tools/libxl/libxl_dm.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/libxl/libxl_dm.c b/tools/libxl/libxl_dm.c
index ad434f0..f700f9a 100644
--- a/tools/libxl/libxl_dm.c
+++ b/tools/libxl/libxl_dm.c
@@ -1095,7 +1095,8 @@ void libxl__spawn_stub_dm(libxl__egc *egc, libxl__stub_dm_spawn_state *sdss)
     libxl_domain_build_info_init_type(&dm_config->b_info, LIBXL_DOMAIN_TYPE_PV);
 
     dm_config->b_info.max_vcpus = 1;
-    dm_config->b_info.max_memkb = 32 * 1024;
+    dm_config->b_info.max_memkb = 28 * 1024 +
+        max_t(uint64_t, guest_config->b_info.video_memkb, 4096);
     dm_config->b_info.target_memkb = dm_config->b_info.max_memkb;
 
     dm_config->b_info.u.pv.features = "";
-- 
1.7.10.4