Commit Graph

3 Commits

Author SHA1 Message Date
Peter Maydell
9c372ecfec docs/system/s390x/protvirt.rst: Format literals correctly
In rST markup, single backticks `like this` represent "interpreted
text", which can be handled as a bunch of different things if tagged
with a specific "role":
https://docutils.sourceforge.io/docs/ref/rst/restructuredtext.html#interpreted-text
(the most common one for us is "reference to a URL, which gets
hyperlinked").

The default "role" if none is specified is "title_reference",
intended for references to book or article titles, and it renders
into the HTML as <cite>...</cite> (usually comes out as italics).

To format a literal (generally rendered as fixed-width font),
double-backticks are required.

protvirt.rst consistently uses single backticks when double backticks
are required; correct it.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Message-id: 20210726142338.31872-7-peter.maydell@linaro.org
2021-08-02 11:42:38 +01:00
David Gibson
651615d92d s390: Recognize confidential-guest-support option
At least some s390 cpu models support "Protected Virtualization" (PV),
a mechanism to protect guests from eavesdropping by a compromised
hypervisor.

This is similar in function to other mechanisms like AMD's SEV and
POWER's PEF, which are controlled by the "confidential-guest-support"
machine option.  s390 is a slightly special case, because we already
supported PV, simply by using a CPU model with the required feature
(S390_FEAT_UNPACK).

To integrate this with the option used by other platforms, we
implement the following compromise:

 - When the confidential-guest-support option is set, s390 will
   recognize it, verify that the CPU can support PV (failing if not)
   and set virtio default options necessary for encrypted or protected
   guests, as on other platforms.  i.e. if confidential-guest-support
   is set, we will either create a guest capable of entering PV mode,
   or fail outright.

 - If confidential-guest-support is not set, guests might still be
   able to enter PV mode, if the CPU has the right model.  This may be
   a little surprising, but shouldn't actually be harmful.

To start a guest supporting Protected Virtualization using the new
option use the command line arguments:
    -object s390-pv-guest,id=pv0 -machine confidential-guest-support=pv0

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
2021-02-08 16:57:38 +11:00
Janosch Frank
42fc5eae91 docs: system: Add protvirt docs
Let's add some documentation for the Protected VM functionality.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Message-Id: <20200319131921.2367-16-frankja@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2020-04-29 14:31:32 +02:00