On Wed, Oct 12, 2011 at 3:52 PM, Jorge Lucangeli Obes <jorgelo@xxxxxxxxxxxx> wrote: > On Wed, Oct 12, 2011 at 12:55 PM, Alexander Graf <agraf@xxxxxxx> wrote: >> >> On 12.10.2011, at 20:49, Jorge Lucangeli Obes wrote: >> >>> Hi all, >>> >>> I'm working on Chromium OS development. We have a pretty elaborate >>> chroot inside of which we carry out all development. We use KVM to >>> launch Chromium OS builds inside a VM for testing. Turns out that for >>> some reason, when QEMU is launched from inside the chroot, KVM itself >>> seems not to be used. The VM is extremely slow. >>> >>> Is this known/expected? QEMU is installed inside the chroot, the KVM >>> modules are loaded, the /dev/kvm device is present and accesible. Any >>> ideas on how to debug this? >> >> The first obvious idea I'd have here would be to strace the qemu process and check what happens when it opens /dev/kvm :) Resending since original attachment was too large. > That's what I thought. I did a test run under strace. I'm attaching > the list of syscalls from the call to 'open(/dev/kvm)' to the first > successful 'ioctl(KVM_RUN)'. /dev/kvm seems to be opened correctly, a > VCPU is created, and then that VCPU is used with KVM_RUN. After the > first call to 'ioctl(KVM_RUN)', there are long lists of more KVM_RUN > calls, separated by brief groups of other calls. So, IIUC, KVM seems > to be used, and seems to be "working", but the VM is one order of > magnitude slower anyways. > > Any ideas? Thanks, Jorge
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