* Avi Kivity <avi@xxxxxxxxxx> wrote: > On 03/16/2010 01:25 PM, Ingo Molnar wrote: > > > >>I haven't followed vmchannel closely, but I think it is. vmchannel is > >>terminated in qemu on the host side, not in the host kernel. So perf would > >>need to connect to qemu. > >Hm, that sounds rather messy if we want to use it to basically expose kernel > >functionality in a guest/host unified way. Is the qemu process discoverable in > >some secure way? > > We know its pid. How do i get a list of all 'guest instance PIDs', and what is the way to talk to Qemu? > > Can we trust it? > > No choice, it contains the guest address space. I mean, i can trust a kernel service and i can trust /proc/kallsyms. Can perf trust a random process claiming to be Qemu? What's the trust mechanism here? > > Is there some proper tooling available to do it, or do we have to push it > > through 2-3 packages to get such a useful feature done? > > libvirt manages qemu processes, but I don't think this should go through > libvirt. qemu can do this directly by opening a unix domain socket in a > well-known place. So Qemu has never run into such problems before? ( Sounds weird - i think Qemu configuration itself should be done via a unix domain socket driven configuration protocol as well. ) > >( That is the general thought process how many cross-discipline useful > > desktop/server features hit the bit bucket before having had any chance of > > being vetted by users, and why Linux sucks so much when it comes to feature > > integration and application usability. ) > > You can't solve everything in the kernel, even with a well populated tools/. Certainly not, but this is a technical problem in the kernel's domain, so it's a fair (and natural) expectation to be able to solve this within the kernel project. Ingo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
