[PATCH] libxl: allow to run non-HVM guest without any device model being available

[PATCH] libxl: allow to run non-HVM guest without any device model being available

[Juergen Gross]

When removing qemu-trad support, libxl__domain_build_info_setdefault()
was modified to only allow qemu-xen as a device model. This change
resulted in an error at domain creation when qemu-xen isn't there.

As this is a perfectly fine situation for PV and PVH guests without
any qemu based backends, handle this case gracefully.

Fixes: 19ab8356abe4 ("tools: remove support for running a guest with qemu-traditional")
Signed-off-by: Juergen Gross <jgross@suse.com>
---
 tools/libs/light/libxl_create.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/libs/light/libxl_create.c b/tools/libs/light/libxl_create.c
index 8a85fba1cf..dad7ad0fda 100644
--- a/tools/libs/light/libxl_create.c
+++ b/tools/libs/light/libxl_create.c
@@ -105,8 +105,8 @@ int libxl__domain_build_info_setdefault(libxl__gc *gc,
         dm = libxl__domain_device_model(gc, b_info);
         rc = access(dm, X_OK);
         if (rc < 0) {
-            LOGE(ERROR, "qemu-xen access error");
-            return ERROR_FAIL;
+            LOGE(INFO, "qemu-xen is unavailable");
+            b_info->device_model_version = LIBXL_DEVICE_MODEL_VERSION_UNKNOWN;
         }
     }
 
-- 
2.43.0

Re: [PATCH] libxl: allow to run non-HVM guest without any device model being available

[Anthony PERARD]

On Fri, Jul 11, 2025 at 11:19:44AM +0200, Juergen Gross wrote:
> When removing qemu-trad support, libxl__domain_build_info_setdefault()
> was modified to only allow qemu-xen as a device model. This change
> resulted in an error at domain creation when qemu-xen isn't there.
> 
> As this is a perfectly fine situation for PV and PVH guests without
> any qemu based backends, handle this case gracefully.
> 
> Fixes: 19ab8356abe4 ("tools: remove support for running a guest with qemu-traditional")
> Signed-off-by: Juergen Gross <jgross@suse.com>

Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>

Thanks,

-- 
Anthony PERARD