[PATCH] docs/about: Automatically deprecate versioned machine types older than 6 years

[Thomas Huth <thuth@redhat.com>]

Old machine types often have bugs or work-arounds that affect our
possibilities to move forward with the QEMU code base (see for example
https://gitlab.com/qemu-project/qemu/-/issues/2213 for a bug that likely
cannot be fixed without breaking live migration with old machine types,
or https://lists.gnu.org/archive/html/qemu-devel/2018-12/msg04516.html or
commit ea985d235b86). So instead of going through the process of manually
deprecating old machine types again and again, let's rather add an entry
that can stay, which declares that machine types older than 6 years are
considered as deprecated automatically. Six years should be sufficient to
support the release cycles of most Linux distributions.

Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 docs/about/deprecated.rst | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst
index 6d595de3b6..fe69e2d44c 100644
--- a/docs/about/deprecated.rst
+++ b/docs/about/deprecated.rst
@@ -220,6 +220,17 @@ is a chance the code will bitrot without anyone noticing.
 System emulator machines
 ------------------------
 
+Versioned machine types older than 6 years
+''''''''''''''''''''''''''''''''''''''''''
+
+Starting with the release of QEMU 10.0, versioned machine types older than
+6 years will automatically be considered as deprecated and might be due to
+removal without furthor notice. For example, this affects machine types like
+pc-i440fx-X.Y, pc-q35-X.Y, pseries-X.Y, s390-ccw-virtio-X.Y or virt-X.Y where
+X is the major number and Y is the minor number of the old QEMU version.
+If you are still using machine types from QEMU versions older than 6 years,
+please update your setting to use a newer versioned machine type instead.
+
 Arm ``virt`` machine ``dtb-kaslr-seed`` property (since 7.1)
 ''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
 
-- 
2.44.0