[Qemu-devel] Qemu custom chardev

[Tanase Sebastian]

Hello everybody,

      I am working on a project that aims to measure how a gui guest application
performs (and by performs I mean whether the virtual time is advancing more rapidly
than the host time) with different icounts (aka. different guest cpu frequencies).

      I would like to know if I could, or if somebody has already done it, add a custom chardev
in Qemu that the guest system could write to. For example, the guest would write to it
before and after an application executes. In Qemu, I could then intercept these
messages and could trace (using simpletrace) the values of the real clock and
virtual clock.
     
      These values would then be used to create a graph and see if the virtual
time advances more than the host time, based on the time difference between
the two clocks.
     
      The final goal is to slow down Qemu (when this is possible of course) in order
to truly emulate the guest cpu at the theoretical frequency imposed by the icount factor.

      I would also like to add that the target system is an arm-versatilepb running Linux and
the host system is an x64 running Linux as well.


Best regards,

Sebastian TANASE