On 2018-01-26 09:03 AM, Stefan Hajnoczi wrote: > > The QEMU -uuid <uuid> option makes a UUID available to the guest via > SMBIOS and fw_cfg on x86. Inside the guest you can print it like this: > > # dmidecode -s system-uuid > 01020304-0506-0708-090A-0B0C0D0E0F10 > > Maybe you can base the guest trace filename off the UUID: > > guest-01020304-0506-0708-090A-0B0C0D0E0F10-trace-001.dat > > On the host you can either find the UUIDs in the libvirt domain XML: > > # virsh dump my-domain > <domain ...> > <uuid>0102030405060708090a0b0c0d0e0f10</uuid> > ... > > Or you can use the kvm.ko uevent to find the QEMU PID and then check > /proc/$PID/cmdline for the uuid. The UUID can also be fetched via the > query-uuid QMP command if you don't want to search /proc/$PID/cmdline > for -uuid <uuid>. > > Maybe you can base the host trace filename off the UUID too: > > host-01020304-0506-0708-090A-0B0C0D0E0F10-trace-001.dat > > Then the ask of correlating traces becomes pretty easy for > post-processing scripts since they can look at the filenames. > > Stefan I think this approach would work. Requiring users to set a uuid to their VM if they plan on tracing it doesn't seem too bad a requirement. Thanks for your help, Geneviève
