ucode=scan usefulness

ucode=scan usefulness

[Jan Beulich]

Konrad,

having been surprised to find your cpio scanning code to not work I
had to realize that this can't possibly work when the initrd is
compressed. Considering that you found this useful nevertheless -
am I to imply that you're running with (and only considering) non-
compressed initrd? Are there plans to support compressed ones too?

Jan

Re: ucode=scan usefulness

[Jan Beulich]

>>> On 05.12.14 at 16:05, <JBeulich@suse.com> wrote:
> having been surprised to find your cpio scanning code to not work I
> had to realize that this can't possibly work when the initrd is
> compressed. Considering that you found this useful nevertheless -
> am I to imply that you're running with (and only considering) non-
> compressed initrd? Are there plans to support compressed ones too?

Never mind, I forgot that the blob gets prefixed uncompressed to
the compressed one, and got confused by seeing a fully compressed
image simply because the installer for some reason decided not to
install any microcode data.

Sorry for the noise,
Jan

Re: ucode=scan usefulness

[Konrad Rzeszutek Wilk]

On Fri, Dec 05, 2014 at 03:05:01PM +0000, Jan Beulich wrote:
> Konrad,
> 
> having been surprised to find your cpio scanning code to not work I
> had to realize that this can't possibly work when the initrd is
> compressed. Considering that you found this useful nevertheless -

Heh. Right.

> am I to imply that you're running with (and only considering) non-
> compressed initrd? Are there plans to support compressed ones too?

I hadn't thought of that use-case as the vehicle to create the
payload is 'dracut'. And its mechanism is to prepend the uncompressed
cpio with microcode to the compressed cpio with normal initramfs.

Thought of course there is nothing stopping to have an compressed
initramfs _with_ the microcode blobs.

I will put this on the Xen 4.6 roadmap.

P.S.
Thought let me double-check that 'dracut' does not compress - it was
not doing that in Fedora 20.
> 
> Jan
>