Re: [Qemu-devel] [PULL 13/76] pvh: Add x86/HVM direct boot ABI header file

[Stefano Garzarella]

On Fri, Mar 01, 2019 at 04:53:57PM +0000, Alex Bennée wrote:
> 
> Paolo Bonzini <address@hidden> writes:
> 
> > From: Liam Merwick <address@hidden>
> >
> > The x86/HVM direct boot ABI permits Qemu to be able to boot directly
> > into the uncompressed Linux kernel binary with minimal firmware involvement.
> >
> >     https://xenbits.xen.org/docs/unstable/misc/pvh.html
> >
> > This commit adds the header file that defines the start_info struct
> > that needs to be populated in order to use this ABI.
> >
> > The canonical version of start_info.h is in the Xen codebase.
> > (like QEMU, the Linux kernel uses a copy as well).
> >
> > Signed-off-by: Liam Merwick <address@hidden>
> > Reviewed-by: Konrad Rzeszutek Wilk <address@hidden>
> > Signed-off-by: Paolo Bonzini <address@hidden>
> 
> This has changed behaviour of a boot. Previously:
> 
>   qemu-system-i386 -serial mon:stdio -nographic -device \
>      isa-debugcon,chardev=serial0 -kernel ./tests/hello
> 

Hi Alex,
is your image in multiboot format?

I sent a patch few weeks ago that fix the loading of multiboot images:
https://www.mail-archive.com/address@hidden/msg596424.html

Thanks,
Stefano

> would boot seabios which then loads the -kernel. Now we get:
> 
>   qemu-system-i386: Error loading uncompressed kernel without PVH ELF Note
> 
> I'm personally not overly concerned (and being able to boot directly
> sounds like a win for my test case). However is this likely to break
> anybodies existing workflow?
> 
> Are there any examples of the minimum setup for a directly booted i386
> kernel image anywhere?
> 
> --
> Alex Bennée
> 

-- 

Stefano Garzarella
Software Engineer @ Red Hat