[xen staging] SUPPORT.md: split XSM from Flask

[patchbot@xxxxxxx]

commit d7c18b8720824d7efc39ffa7296751e1812865a9
Author:     Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Wed Sep 4 16:05:03 2024 +0200
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Wed Sep 4 16:05:03 2024 +0200

    SUPPORT.md: split XSM from Flask
    
    XSM is a generic framework, which in particular is also used by SILO.
    With this it can't really be experimental: Arm mandates SILO for having
    a security supported configuration.
    
    Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
    Reviewed-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
    Reviewed-by: Daniel P. Smith <dpsmith@xxxxxxxxxxxxxxxxxxxx>
---
 SUPPORT.md | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/SUPPORT.md b/SUPPORT.md
index f822a7e607..23dd7e6424 100644
--- a/SUPPORT.md
+++ b/SUPPORT.md
@@ -769,13 +769,21 @@ Compile time disabled for ARM by default.
 
     Status, x86: Supported, not security supported
 
-### XSM & FLASK
+### XSM (Xen Security Module) Framework
+
+XSM is a security policy framework.  The dummy implementation is covered by 
this
+statement, and implements a policy whereby dom0 is all powerful.  See below for
+alternative modules (FLASK, SILO).
+
+    Status: Supported
+
+### FLASK XSM Module
 
     Status: Experimental
 
 Compile time disabled by default.
 
-Also note that using XSM
+Also note that using FLASK
 to delegate various domain control hypercalls
 to particular other domains, rather than only permitting use by dom0,
 is also specifically excluded from security support for many hypercalls.
@@ -788,6 +796,13 @@ Please see XSA-77 for more details.
 The default policy includes FLASK labels and roles for a "typical" Xen-based 
system
 with dom0, driver domains, stub domains, domUs, and so on.
 
+### SILO XSM Module
+
+SILO extends the dummy policy by enforcing that DomU-s can only communicate
+with Dom0, yet not with each other.
+
+    Status: Supported
+
 ## Virtual Hardware, Hypervisor
 
 ### x86/Nested PV
--
generated by git-patchbot for /home/xen/git/xen.git#staging