On Thu, Apr 04, 2019 at 09:49:16 +0100, Daniel Berrange wrote:
On Thu, Apr 04, 2019 at 10:01:27AM +0200, Bjoern Walk wrote:
This patch series introduces the ability to save additional information for the domain state and exposes this information in virsh domstate.
For example in the case of QEMU guest panic events, we can provide additional information like the crash reason or register state of the domain. This information usually gets logged in the domain log but for debugging it is useful to have it accessible from the client. Therefore, let's introduce a new public API function, virDomainGetStateParams, an extensible version of virDomainGetState, which returns the complete state of the domain, including newly introduced additional information.
Let's also extend virsh domstate and introduce a new parameter --info to show the domain state, reason and additional information when available.
virsh # domstate --info guest-1 crashed (panicked) s390.core = 0 s390.psw-mask = 0x0002000180000000 s390.psw-addr = 0x000000000010f146 s390.reason = disabled-wait
This info is all just guest panick related data, so I'm not covinced we should overload "domstate" for this random set of low level hardware parameters.
I'm not even sure whether it's worth having an API to query it at all. We don't really have means to store the data reliably across libvirtd restarts as there is no status XML for inactive VMs. This means that the data will get lost. It also will become instantly invalidated when starting the VM. Currently we log the data into the domain log file which in my opinion feels good enough for this kind of low level information which is not of much use for non-devs. Additionally the advantage of logging is that bug reporting tools usually capture the VM log files.