Re: [PATCH v1] qemu: monitor: substitute missing model name for host-passthrough
One more ping in attempt to get this in the right direction. Otherwise
I'll post my next idea and we can go from there :)
Thinking about this issue, should a host-passthough CPU definition be
permitted for the baseline & comparison commands? The model represented
under this mode is not considered migration safe and it may make sense
to simply fail early since these commands aim to construct/determine a
migratable CPU model, respectively.
Perhaps if a host-passthrough CPU is detected, then an error reporting
something along the lines of "host-passthrough is not supported for
migration" would be sufficient for this?
Thanks again. Hope all is well.
On 8/19/20 11:05 AM, Collin Walling wrote:
Polite ping to the mailing list regarding this bug. I recall the
logic I
proposed belongs elsewhere, but I'd like to kindly request a followup
from the respective maintainer(s) for a direction.
Thanks!
On 6/26/20 2:31 PM, Collin Walling wrote:
> On 6/26/20 3:22 AM, Peter Krempa wrote:
>> On Thu, Jun 25, 2020 at 17:58:46 -0400, Collin Walling wrote:
>>> When executing the hypervisor-cpu-compare/baseline commands and
>>> the XML file contains a CPU definition using host-passthrough
>>> and no model name, the commands will fail and return an error
>>> message from the QMP response.
>>
>> This kind of logic does not seem to belong ...
>>
>>> Let's fix this by checking for host-passthrough and a missing
>>> model name when converting a CPU definition to a JSON object.
>>> If these conditions are matched, then the JSON object will be
>>> constructed using "host" as the model name.
>>>
>>> Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1850680
>>>
>>> Signed-off-by: Collin Walling <walling(a)linux.ibm.com>
>>> ---
>>> src/qemu/qemu_monitor_json.c | 13 ++++++++++++-
>>> 1 file changed, 12 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c
>>> index 3070c1e6b3..448a3a9356 100644
>>> --- a/src/qemu/qemu_monitor_json.c
>>> +++ b/src/qemu/qemu_monitor_json.c
>>> @@ -5804,9 +5804,20 @@ qemuMonitorJSONMakeCPUModel(virCPUDefPtr cpu,
>>> {
>>> virJSONValuePtr model = virJSONValueNewObject();
>>> virJSONValuePtr props = NULL;
>>> + const char *model_name = cpu->model;
>>> size_t i;
>>>
>>> - if (virJSONValueObjectAppendString(model, "name",
cpu->model) < 0)
>>> + if (!model_name) {
>>> + if (cpu->mode == VIR_CPU_MODE_HOST_PASSTHROUGH) {
>>> + model_name = "host";
>>> + } else {
>>> + virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
>>> + _("cpu parameter is missing a model
name"));
>>> + goto error;
>>> + }
>>> + }
>>
>> ... to the monitor code, where we try to just deal with the monitor
>> itself rather than hiding any logic.
>>
>
> That's fair. Perhaps it should belong to the qemu driver code after the
> CPU XML to a CPU def conversion. I'm also unsure if "host" is an s390
> specific thing, or if other archs use it as well.
>
>> But the final word needs to be from Jirka, but he is on holidays until
>> the end of next week.
>>
>>
>>> +
>>> + if (virJSONValueObjectAppendString(model, "name", model_name)
< 0)
>>> goto error;
>>>
>>> if (cpu->nfeatures || !migratable) {
>>> --
>>> 2.26.2
>>>
>>
>
>