[libvirt] [PATCH] libxl: allow an <emulator> to be selected in the domain config XML
The emulator path supplied can be any valid path on the system.
Note that when setting a device_model, libxl needs us to set the
device_model_version too. The device_model_version can be either
...QEMU_XEN: meaning "upstream qemu", the default in xen-4.3 onwards
...QEMU_XEN_TRADITIONAL: the old xen-specific fork
We detect the device_model_version by examining the qemu filename:
if it is "qemu-dm" then it's the old xen-specific fork. If anything
else then we assume "upstream qemu" (whose filename may change
in future). Note that if you are using a wrapper script to (eg)
adjust the arguments of the old qemu during development, you will
have to ensure the wrapper script also has the name "qemu-dm", by
placing it in a separate directory.
Signed-off-by: David Scott <dave.scott(a)eu.citrix.com>
---
src/libxl/libxl_conf.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 44 insertions(+), 0 deletions(-)
diff --git a/src/libxl/libxl_conf.c b/src/libxl/libxl_conf.c
index 7e0753a..2aa5a62 100644
--- a/src/libxl/libxl_conf.c
+++ b/src/libxl/libxl_conf.c
@@ -788,6 +788,46 @@ libxlMakeCapabilities(libxl_ctx *ctx)
}
int
+libxlMakeEmulator(virDomainDefPtr def, libxl_domain_config *d_config)
+{
+ /* No explicit override means use the default */
+ if (!def->emulator) {
+ return 0;
+ }
+
+ if (!virFileExists(def->emulator)) {
+ virReportError(VIR_ERR_INTERNAL_ERROR,
+ _("emulator '%s' not found"),
+ def->emulator);
+ return -1;
+ }
+
+ VIR_FREE(d_config->b_info.device_model);
+ if ((d_config->b_info.device_model = strdup(def->emulator)) == NULL) {
+ virReportOOMError();
+ return -1;
+ }
+
+ /* N.B. from xen/tools/libxl/libxl_types.idl:
+ * "If setting device_model you must set device_model_version too."
+ *
+ * The xen-4.3 and later default is "upstream qemu" (QEMU_XEN)
+ * so we make that the default and special-case the old-style
+ * "traditional qemu" (QEMU_XEN_TRADITIONAL)
+ */
+
+ d_config->b_info.device_model_version =
+ LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN;
+
+ if (STREQ(basename(def->emulator), "qemu-dm"))
+ d_config->b_info.device_model_version =
+ LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN_TRADITIONAL;
+
+ return 0;
+}
+
+
+int
libxlBuildDomainConfig(libxlDriverPrivatePtr driver,
virDomainDefPtr def, libxl_domain_config *d_config)
{
@@ -811,6 +851,10 @@ libxlBuildDomainConfig(libxlDriverPrivatePtr driver,
goto error;
}
+ if (libxlMakeEmulator(def, d_config) < 0) {
+ goto error;
+ }
+
d_config->on_reboot = def->onReboot;
d_config->on_poweroff = def->onPoweroff;
d_config->on_crash = def->onCrash;
--
1.7.1