Re: [Qemu-devel] Announcing qboot, a minimal x86 firmware for QEMU

[Avi Kivity <avi@cloudius-systems.com>]

On 05/21/2015 04:51 PM, Paolo Bonzini wrote:
> Some of you may have heard about the "Clear Containers" initiative from
> Intel, which couple KVM with various kernel tricks to create extremely
> lightweight virtual machines.  The experimental Clear Containers setup
> requires only 18-20 MB to launch a virtual machine, and needs about 60
> ms to boot.
>
> Now, as all of you probably know, "QEMU is great for running Windows or
> legacy Linux guests, but that flexibility comes at a hefty price. Not
> only does all of the emulation consume memory, it also requires some
> form of low-level firmware in the guest as well. All of this adds quite
> a bit to virtual-machine startup times (500 to 700 milliseconds is not
> unusual)".
>
> Right?  In fact, it's for this reason that Clear Containers uses kvmtool
> instead of QEMU.
>
> No, wrong!  In fact, reporting bad performance is pretty much the same
> as throwing down the gauntlet.
>
> Enter qboot, a minimal x86 firmware that runs on QEMU and, together with
> a slimmed-down QEMU configuration, boots a virtual machine in 40
> milliseconds[2] on an Ivy Bridge Core i7 processor.
>
> qboot is available at git://github.com/bonzini/qboot.git.  In all the
> glory of its 8KB of code, it brings together various existing open
> source components:
>
> * a minimal (really minimal) 16-bit BIOS runtime based on kvmtool's own BIOS
>
> * a couple hardware initialization routines written mostly from scratch
> but with good help from SeaBIOS source code
>
> * a minimal 32-bit libc based on kvm-unit-tests
>
> * the Linux loader from QEMU itself
>
> The repository has more information on how to achieve fast boot times,
> and examples of using qboot.  Right now there is a limit of 8 MB for
> vmlinuz+initrd+cmdline, which however should be enough for initrd-less
> containers.
>
> The first commit to qboot is more or less 24 hours old, so there is
> definitely more work to do, in particular to extract ACPI tables from
> QEMU and present them to the guest.  This is probably another day of
> work or so, and it will enable multiprocessor guests with little or no
> impact on the boot times.  SMBIOS information is also available from QEMU.
>
> On the QEMU side, there is no support yet for persistent memory and the
> NFIT tables from ACPI 6.0.  Once that (and ACPI support) is added, qboot
> will automatically start using it.
>
> Happy hacking!
>

Lovely!

Note you have memcpy.o instead of memcpy.c.