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

[Alex Bennée]

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

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