* Avi Kivity<avi@xxxxxxxxxx> wrote:
I wouldnt jump to assumptions there. perf shares some facilities with theThat is not what i said. I said they are closely related, and whereI really don't see how. So what if both qemu and kvm implement an i8254?
technologies are closely related, project proximity turns into project
unification at a certain stage.
They can't share any code since the internal APIs are so different. [...]
kernel on the source code level - they can be built both in the kernel and in
user-space.
But my main thought wasnt even to actually share the implementation - but to
actually synchronize when a piece of device emulation moves into the kernel.
It is arguably bad for performance in most cases when Qemu handles a given
device - so all the common devices should be kernel accelerated.
The version and testing matrix would be simplified significantly as well: as
kernel and qemu goes hand in hand, they are always on the same version.
[...] Even worse for the x86 emulator as qemu and kvm are fundamentallySo is it your argument that the difference and the duplication in x86
different.
instruction emulation is a good thing?
You said it some time ago that
the kvm x86 emulator was very messy and you wish it was cleaner.
While qemu's is indeed rather different (it's partly a translator/JIT), i'm
sure the decoder logic could be shared - and qemu has a slow-path
full-emulation fallback in any case, which is similar to what in-kernel
emulator does (IIRC ...).
That might have changed meanwhile.