Files
xen/docs
Andrew Cooper 87ff11354f x86/spec-ctrl: Add spec-ctrl=unpriv-mmio
Per Xen's support statement, PCI passthrough should be to trusted domains
because the overall system security depends on factors outside of Xen's
control.

As such, Xen, in a supported configuration, is not vulnerable to DRPW/SBDR.

However, users who have risk assessed their configuration may be happy with
the risk of DoS, but unhappy with the risk of cross-domain data leakage.  Such
users should enable this option.

On CPUs vulnerable to MDS, the existing mitigations are the best we can do to
mitigate MMIO cross-domain data leakage.

On CPUs fixed to MDS but vulnerable MMIO stale data leakage, this option:

 * On CPUs susceptible to FBSDP, mitigates cross-domain fill buffer leakage
   using FB_CLEAR.
 * On CPUs susceptible to SBDR, mitigates RNG data recovery by engaging the
   srb-lock, previously used to mitigate SRBDS.

Both mitigations require microcode from IPU 2022.1, May 2022.

This is part of XSA-404.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
(cherry picked from commit 8c24b70fed)
2022-06-16 13:40:24 +01:00
..
2019-03-13 13:40:23 +00:00
2018-11-14 19:25:11 +00:00
2020-05-05 15:12:47 +01:00
2016-04-01 11:07:28 +08:00

Sphinx documentation:

All source rendered by Sphinx is licensed under CC-BY-4.0.

You are free to:
  Share:
    Copy and redistribute the material in any medium or format.
  Adapt:
    Remix, transform, and build upon the material for any purpose, even
    commercially.

Under the following terms:
  Attribution:
    You must give appropriate credit, provide a link to the license, and
    indicate if changes were made. You may do so in any reasonable manner, but
    not in any way that suggests the licensor endorses you or your use.
  No additional restrictions:
    You may not apply legal terms or technological measures that legally
    restrict others from doing anything the license permits.

See https://creativecommons.org/licenses/by/4.0/ for full details.

This includes:
  * All ReStructured Text files:          docs/*/*.rst
  * The Sphinx configuration file:        docs/conf.py
  * Content in Sphinx-exclusive subdirs:  docs/*-guide/*


Other documentation:

There are a variety of text documents in various formats.  These, given no
explicit license guidance, fall under Xen's default GPL-2.0 license.