Thanks for reposting this Paolo. I tested it by applying it on top of qemu. In libguestfs sources we have a benchmark program called utils/boot-benchmark/boot-benchmark.
Using the qemu package from Fedora (qemu-2.6.0-3.fc24.x86_64): $ killall -STOP firefox $ ./boot-benchmark Result: 2341.7ms ±10.9ms With the unpatched upstream qemu: $ LIBGUESTFS_HV=~/d/qemu/x86_64-softmmu/qemu-system-x86_64 ./boot-benchmark Result: 2282.3ms ±1.7ms With the patched upstream qemu: $ LIBGUESTFS_HV=~/d/qemu/x86_64-softmmu/qemu-system-x86_64 ./boot-benchmark Result: 1452.4ms ±0.9ms So the patch works and makes a significant difference. Note I still had to do by hand: $ cp pc-bios/optionrom/linuxboot_dma.bin pc-bios/ Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-builder quickly builds VMs from scratch http://libguestfs.org/virt-builder.1.html
