On 01/13/2017 05:04 AM, Jiri Denemark wrote:
On Thu, Jan 12, 2017 at 11:18:11 -0500, Collin L. Walling wrote:When running on s390 with a kernel that does not support cpu model checking and with a Qemu new enough to support query-cpu-model-expansion, the gathering of qemu capabilities will fail. Qemu responds to the query-cpu-model-expansion qmp command with an error because the needed kernel ioct does not exist. When this happens a guest cannot even be defined due to missing qemu capabilities data. This patch fixes the problem by silently ignoring generic errors stemming from calls to query-cpu-model-expansion. Reported-by: Farhan Ali <alifm@xxxxxxxxxxxxxxxxxx> Signed-off-by: Collin L. Walling <walling@xxxxxxxxxxxxxxxxxx> Signed-off-by: Jason J. Herne <jjherne@xxxxxxxxxxxxxxxxxx> --- src/qemu/qemu_monitor_json.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c index e767437..1662749 100644 --- a/src/qemu/qemu_monitor_json.c +++ b/src/qemu/qemu_monitor_json.c @@ -5041,6 +5041,15 @@ qemuMonitorJSONGetCPUModelExpansion(qemuMonitorPtr mon, if (qemuMonitorJSONCommand(mon, cmd, &reply) < 0) goto cleanup; + /* Some QEMU architectures have the query-cpu-model-expansion + * command, but return 'GenericError' instead of simply omitting + * the command entirely. + */Hmm, this comment says something a bit different than the commit message. I hope the issue described by this comment was fixed in QEMU within the same release the query-cpu-model-expansion command was introduced. But we need to fix this nevertheless to address what the commit message describes.
The issue still exists in Qemu. I can work up a patch to handle it. My first idea is to simply test that the ioctl exists and functions at Qemu initialization and deregister the query-cpu-model-expansion command in the event that the ioctl does not exist or fails. Thoughts?
However, we need to do a little bit more than just ignoring this error. I'll send a v2 soon.
-- -- Jason J. Herne (jjherne@xxxxxxxxxxxxxxxxxx) -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list
