Von: Andreas Färber <address@hidden>
Datum: 2. Juli 2011 19:21:07 MESZ
An: Ben Vogler <address@hidden>
Kopie: Hans de Goede <address@hidden>, Alon Levy <address@hidden
>
Betreff: Re: [Qemu-devel] Benchmarking activities
Hi Ben,
Am 27.06.2011 um 01:02 schrieb Ben Vogler:
- I have seen examples of QEMU processor cores being
wrapped in SystemC and used in OSCI based virtual systems is this
the general approach, or is there other/better ways of going about
using QEMU not as an emulator (such as VMware), but as a simulator?
(VMware like KVM and VirtualBox, I thought, was doing virtualization
rather than emulation.)
QEMU uses a device model called qdev. Your device can set up
handlers for I/O accesses and then do anything it likes from C code.
Be it obtaining data from a local device (passthrough) or from a
remote server (e.g., USB redirection) or via socket from an external
process (e.g., usb-ccid).
- Is there full backwards compatibility between versions
of QEMU?
Define what architecture/machine you use and what exactly you want
to be backwards compatible.
As examples, command line options and device state (VMState) are
being kept backwards compatible for x86 PC so that you can load old
snapshots, whereas the QEMU-internal APIs may evolve incompatibly
(v0.9.x is highly incompatible with recent versions, for instance).
- I have been looking but could not find a complete list
of processor core models supported by QEMU. I have seen there are
processors from Sparc, ARM, MIPS, but are there any core models
from NEC, or Renesas in particular? Would you please be able to
point me in the right direction?
There are a couple of forks on the Internet adding support for
additional architectures, but no Renesas that I'm aware of.
http://wiki.qemu.org/Links -> Alternate QEMU repositories
http://wiki.qemu.org/Contribute/StartHere -> Features
http://repo.or.cz/w/qemu.git/forks
I have a v850 board around but adding a QEMU target for it just to
debug a few LEDs and GPIOs seemed like overkill.
Still waiting for an RL78 starter kit...
If you find or contribute anything in that area I'll be happy to
help review patches.
The rest of my questions are based on the assumption that QEMU IP
will be used in a virtual system simulation, rather than emulation.
- Is co-simulation possible? For example, connecting an
engine model running in Dymola to the QEMU (processor model) based
virtual system simulator.
Since that particular product seems closed-source and the demo
download is for Windows only, it's hard to tell. As stated above,
it's possible to communicate with external processes or clients/
servers from QEMU. In which ways particular simulators support
receiving external queries or publishing internal state would be for
the simulator's authors to answer.
I've heard of the IEEE 1516 High Level Architecture (HLA) as a
general way of synchronizing distributed simulations but haven't
worked with it personally.
Regards,
Andreas