[Sound-open-firmware] DSP VM to x86 VM communication in QEMU

[Liam Girdwood]

On Tue, 2019-04-16 at 18:26 +0300, Kai Vehmanen wrote:
> Hi,
> 
> On Mon, 15 Apr 2019, Liam Girdwood wrote:
> 
> > https://www.alsa-project.org/main/index.php/Firmware#Using_the_Qemu_DSP_emulator
> > 
> > These instructions are out of date, so you may find that other qemu
> > dependencies
> > are needed to build. Host (x86) side is not yet supported for SKL on wards
> > atm
> > (needs code to hook into qemu HDA core), but xtensa DSP is supported on all
> > platforms.
> 
> I can verify the DSP side is functional and I could set up an environment
> following the wiki and run latest and greatest FW from SOF mainline.
> 
> There is some regression with host side though, even when trying to use 
> older targets than SKL. I reverted the SOF qemu branch to v1.2 level and
> ta-daa, I got both sides working (with latest driver and fw, BYT target).
> 
> I'll next bisect the commits since v1.2 to see where it broke down.
> 

Fwiw, Ranjani and I have also found that some of the Posix IPC e.g. threads,
SHM, message queues (not FW IPC) between the qemu VMs may not been following the
correct close/shutdown programming flow. This means subsequent qemu invocations
were not always working. This was found as part of the FW IPC fuzzer work.

Btw, if interested in fuzzer, see lrg/topic/fuzzer branch on sof git for WIP
fuzzer code.

Liam