--On 26 July 2013 10:43:45 +0200 Stefan Hajnoczi <stefa...@gmail.com> wrote:
block.c and block/qed.c use vm_clock because block drivers should not do guest I/O while the vm is stopped. This is especially true during live migration where it's important to hand off the image file from the source host to the destination host with good cache consistency. The source host is not allowed to modify the image file anymore once the destination host has resumed the guest. Block jobs use rt_clock because they aren't considered guest I/O.
That's going to be 'interesting' if qemu-img uses a block driver that uses a timer, as I don't think the vm timer is running when qemu-img is running. -- Alex Bligh
