Re: 回复：Any interest in a QEMU emulation BoF at KVM Forum?

[Alex Bennée]

"刘志伟" <zhiwei_liu@c-sky.com> writes:

> These topics are interesting.  I have two questions.
>
> 1. Can we join it on online?  If so, could you share the meeting link
> before the meeting.

I will try to find out.

>
> 2. If it is only offline, could you share the meeting content to the
> public?

I'll certainly try and write up some minutes for the list.

>
> Thanks,
> Zhiwei 
>
>  ------------------------------------------------------------------
>  发件人：Alex Bennée <alex.bennee@linaro.org>
>  发送时间：2022年9月1日(星期四) 01:08
>  收件人：qemu-devel@nongnu.org <qemu-devel@nongnu.org>
>  抄　送：Mark Burton <mburton@qti.qualcomm.com>; Edgar E. Iglesias 
> <edgar.iglesias@gmail.com>; Richard
>  Henderson <richard.henderson@linaro.org>; Paolo Bonzini 
> <pbonzini@redhat.com>; Peter Maydell
>  <peter.maydell@linaro.org>; Song Gao <gaosong@loongson.cn>; Xiaojuan Yang 
> <yangxiaojuan@loongson.cn>;
>  "Cédric Le Goater" <clg@kaod.org>; Palmer Dabbelt <palmer@dabbelt.com>; 
> Alistair Francis
>  <alistair.francis@wdc.com>; Bin Meng <bin.meng@windriver.com>; David Gibson 
> <david@gibson.dropbear.id.au>;
>  Markus Armbruster <armbru@redhat.com>; Michael Roth <michael.roth@amd.com>; 
> Luc Michel <luc@lmichel.fr>;
>  Damien Hedde <damien.hedde@greensocs.com>; Alessandro Di Federico 
> <ale@rev.ng>
>  主　题：Re: Any interest in a QEMU emulation BoF at KVM Forum?
>
>  Alex Bennée <alex.bennee@linaro.org> writes:
>
>  qemu-devel keeps bouncing the message so replying with a cut down CC list.
>
>  > Hi,
>  >
>  > Given our slowly growing range of TCG emulations and the evident
>  > interest in keeping up with modern processor architectures is it worth
>  > having an emulation focused BoF at the up-coming KVM Forum?
>  >
>  > Some potential topics for discussion I could think of might include:
>  >
>  >  * Progress towards heterogeneous vCPU emulation
>  >
>  >  We've been making slow progress in removing assumptions from the
>  >  various front-ends about their global nature and adding accel:TCG
>  >  abstractions and support for the translator loop. We can already have
>  >  CPUs from the same architecture family in a model. What else do we need
>  >  to do so we can have those funky ARM+RiscV+Tricore heterogeneous
>  >  models? Is it library or something else?
>  >
>  >  * External Device Models
>  >
>  >  I know this is a contentious topic given the potential for GPL
>  >  end-runs. However there are also good arguments for enabling the
>  >  testing of open source designs without having forcing the
>  >  implementation of a separate C model to test software. For example if
>  >  we hypothetically modelled a Pi Pico would it make sense to model the
>  >  PIO in C if we could just compile the Verilog for it into a SystemC
>  >  model? Would a plethora of closed device models be the inevitable
>  >  consequence of such an approach? Would it matter if we just
>  >  concentrated on supporting useful open source solutions?
>  >
>  >  * Dynamic Machine Models
>  >
>  >  While we try and avoid modelling bespoke virtual HW in QEMU
>  >  (virt/goldfish not withstanding ;-) there is obviously a desire in the
>  >  EDA space to allow such experimentation. Is this something we can
>  >  provide so aspiring HW engineers can experiment with system
>  >  architectures without having to form QEMU and learn QOM. There have
>  >  been suggestions about consuming device trees or maybe translating to
>  >  QMP calls and adding support for wiring devices together. Given the
>  >  number of forks that exist is this something that could be better
>  >  supported upstream without degenerating into messy hacks?
>  >
>  >  * A sense of time
>  >
>  >  Currently we have the fairly limited support for -icount in QEMU. At
>  >  the same time we have no desire to start expanding frontends with
>  >  the details cost models required for a more realistic sense of time to
>  >  be presented. One suggestion is to expand the TCG plugin interface to
>  >  allow for the plugin to control time allowing as much or little logic
>  >  to be pushed there as we like and freeing up frontends from ever having
>  >  to consider it.
>  >
>  > Are any of these topics of interest? Are there any other emulation
>  > topics people would like to discuss?
>
>  -- 
>  Alex Bennée


-- 
Alex Bennée