On Mon, Jun 01, 2020 at 02:40:25PM +0100, Andrew Cooper wrote:
> Extend the disclaimer about runtime loading. While we've done our best to
> make the mechaism reliable, the safety of late loading does ultimately depend
> on the contents of the blobs.
>
> Extend the xen-ucode portion with examples of how to use it.
>
> Signed-off-by: Andrew Cooper <andrew.coop...@citrix.com>
Reviewed-by: Roger Pau Monné <roger....@citrix.com>
> ---
> CC: George Dunlap <george.dun...@eu.citrix.com>
> CC: Ian Jackson <ian.jack...@citrix.com>
> CC: Jan Beulich <jbeul...@suse.com>
> CC: Konrad Rzeszutek Wilk <konrad.w...@oracle.com>
> CC: Stefano Stabellini <sstabell...@kernel.org>
> CC: Wei Liu <w...@xen.org>
> CC: Julien Grall <jul...@xen.org>
> CC: Paul Durrant <p...@xen.org>
> ---
> docs/admin-guide/microcode-loading.rst | 22 +++++++++++++++++++---
> 1 file changed, 19 insertions(+), 3 deletions(-)
>
> diff --git a/docs/admin-guide/microcode-loading.rst
> b/docs/admin-guide/microcode-loading.rst
> index 5f0f661a2e..8cd5d0351b 100644
> --- a/docs/admin-guide/microcode-loading.rst
> +++ b/docs/admin-guide/microcode-loading.rst
> @@ -104,8 +104,8 @@ modules to find any CPIO archives, and search the archive
> for the applicable
> file. Xen will stop searching at the first match.
>
>
> -Run time microcode loading
> ---------------------------
> +Runtime microcode loading
> +-------------------------
>
> .. warning::
>
> @@ -113,7 +113,23 @@ Run time microcode loading
> or at boot time. Not all microcode updates (or parts thereof) can be
> applied at runtime.
>
> -The ``xen-ucode`` utility can be used to initiate a runtime microcode load.
> + Given the proprietry nature of microcode, we are unable to make any claim
> + that a runtime microcode is risk-free. Any runtime microcode loading
> needs
> + adequate testing on a dev instance before being rolled out to production
> + systems.
> +
> +The ``xen-ucode`` utility can be used to initiate a runtime microcode load::
> +
> + [root@host ~]# xen-ucode
> + xen-ucode: Xen microcode updating tool
> + Usage: xen-ucode <microcode blob>
> + [root@host ~]#
> +
> +e.g. With a Linux dom0 on a Haswell system::
> +
> + [root@host ~]# xen-ucode /lib/firmware/intel-ucode/06-3c-03
Could you expand a bit on the nomenclature used here?
I assume it's something like <fam>-<model>-<version> but might be good
to provide people a hint to know how to find the appropriate blob for
their system if possible.
Thanks, Roger.
