libxenlight: implement stubdom support

this patch implements stubdom support for libxenlight:

- it adds two functions to find the stubdom domid of a domain and to
figure out if a certain domain is actually a stubdom;

- it moves all the device init functions from xl.c to libxl.c because
they are needed to setup the devices of stubdoms;

- it fixes some bugs in the pci setup that prevented pci passthrough
from working correctly with stubdoms.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

1 files changed, 19 insertions, 0 deletions

diff --git a/tools/libxl/libxl_utils.c b/tools/libxl/libxl_utils.c
index 69e3ba9879..358f735b4f 100644
--- a/tools/libxl/libxl_utils.c
+++ b/tools/libxl/libxl_utils.c
@@ -168,3 +168,22 @@ int libxl_param_to_domid(struct libxl_ctx *ctx, char *p, uint32_t *domid)
     }
     return libxl_name_to_domid(ctx, p, domid);
 }
+
+int libxl_get_stubdom_id(struct libxl_ctx *ctx, int guest_domid)
+{
+    char * stubdom_id_s = libxl_xs_read(ctx, XBT_NULL, libxl_sprintf(ctx, "%s/image/device-model-domid", libxl_xs_get_dompath(ctx, guest_domid)));
+    if (stubdom_id_s)
+        return atoi(stubdom_id_s);
+    else
+        return 0;
+}
+
+int libxl_is_stubdom(struct libxl_ctx *ctx, int domid)
+{
+    char *target = libxl_xs_read(ctx, XBT_NULL, libxl_sprintf(ctx, "%s/target", libxl_xs_get_dompath(ctx, domid)));
+    if (target)
+        return 1;
+    else
+        return 0;
+}
+