On Thu, Feb 24, 2011 at 11:23 AM, Jelle van der Waa <jelle@xxxxxxxx> wrote: > On Thu, 2011-02-24 at 11:07 -0600, C Anthony Risinger wrote: >> hmm, soo qemu doesn't actually use the VT extensions? wtf is the >> point then? > QEMU is an emulator -> so for ARM for example >> this is what i don't understand; if qemu supports KVM via >> the `-enable-kvm` switch why does it suck so much -- it seems just as >> slow to me as no KVM support at all. > > Here it's not, are you using qemu-kvm or some selfcompiled version? qemu-kvm is always fast. qemu is never fast -- libvirt uses `-enable-kvm` when i tell it to, ie. for either package. i've tried recompiling the regular `qemu` package with explicit KVM support, and the speed is still absolutely abysmal. >> I have a server that runs >> several KVM/libvirt instances (windows being one of them purely for >> ... i dont even know) so i'm pretty familiar with it all, but i'm just >> trying to get solid info why there is such a huge performance gap when >> the both "use KVM". i thought KVM itself did all the VT handling. > > Another tip for kvm usage is installing your OS on virtio [1] already do :-) i use all the virtio drivers -- when i say perf is bad i mean it's like KVM isnt even working. i haven't `lsof` yet to make sure qemu (not qemu-kvm!!) is actually opening the /dev/kvm device. i read thru the packages of both. i tried symlinking `/usr/bin/qemu-kvm -> qemu-system-x86_64` (this is what qemu-kvm package does) ... no difference. so my real question is, is anyone using the upstream package `qemu`, with KVM, and getting proper results? are good results expected? what am i missing here. C Anthony
