Re: [Qemu-devel] Re: KQEMU code organization

[Fabrice Bellard]

Jan Kiszka wrote:
> Fabrice Bellard wrote:
> > Jan Kiszka wrote:
> > > Fabrice Bellard wrote:
> > > > Jan Kiszka wrote:
> > > > > Hi,
> > > > >
> > > > > is there a technical reason why the kqemu kernel module is built out of
> > > > > a binary blob (monitor-image.bin->monitor-image.h)? Does this simply
> > > > > date back to the time when wrapper and core were distributed under
> > > > > different licenses?
> > > > This is a technical reason: the "blob" is run in an address space
> > > > different from the host kernel.
> > > Well, easy to claim, I know, but I don't think this is a hard reason.
> > > However, as overcoming genmon and genoffset may require quite some
> > > refactoring, I'm not sure if it's worth it.
> > I may change the monitor blob format to ELF to allow relocation, but the
> > idea stays the same, and I don't think you can do it another way...
>
> I agree (from my current knowledge of the problem) that the monitor
> remains "foreign" code to the kernel module. But at least the
> repackaging into a c-structure should be unnecessary.
>
> The offset generation can be skipped if the assembly files are converted
> into inline assembly. Might be tricky in some cases, but I see no
> show-stopper yet.

This is purely cosmetic and I am generally against such changes.

> The give it a tiny start, I will look if I can unify the build process
> for all "true" kernel components. That is what currently breaks the
> debugability of the driver frame (up to kernel2monitor), and which also
> causes a kbuild warning. Likely harmless ATM, but it is fragile on
> long-term.

For true kernel components I agree it is useful.

Regarding the kqemu evolution, I am doing small API changes to make it 
more independent from the QEMU internal data structures and to allow 
usage from a 32 bit user QEMU application with a 64 bit host. There is 
also another small change I did some time ago but never published to 
allow paravirtualization of the Linux kernel.

Fabrice.