On Fri, Apr 01, 2016 at 10:24:37AM +0200, Paolo Bonzini wrote: > On 01/04/2016 10:14, Richard W.M. Jones wrote: > > Found it: only CONFIG_MPTABLE=y was necessary. It boots with: > > > > # CONFIG_PIRTABLE is not set > > CONFIG_MPTABLE=y > > # CONFIG_SMBIOS is not set > > # CONFIG_ACPI is not set > > If you add all three it should not give any slowdown and will provide > full hardware features to the kernel. qboot does ACPI and PCI bus > assignment (it doesn't do SMBIOS because I got bored debugging it. :))
Enabling all 4 adds about 2ms. However the overhead of SeaBIOS is still down from 68ms to 18ms (4.0% of total boot time down to 1.1%) so it's still a big gain. I wonder how we can make use of this in qemu and downstream distros? Can we have a bios-min.bin which is used with -kernel boots? Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com libguestfs lets you edit virtual machines. Supports shell scripting, bindings from many languages. http://libguestfs.org
