[PATCH v2 2/6] docs/about/removed-features: Document removed CLI options from QEMU v3.0

[Thomas Huth <thuth@redhat.com>]

These CLI options had been removed/replaced in QEMU v3.0. Still, some
people might want to update from older versions to the recent QEMU version,
so we should give some recommendations for the replacements in our
documentation.

Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 docs/about/removed-features.rst | 35 +++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/docs/about/removed-features.rst b/docs/about/removed-features.rst
index c18af3c76f..c4b702968e 100644
--- a/docs/about/removed-features.rst
+++ b/docs/about/removed-features.rst
@@ -44,6 +44,41 @@ behaviour that could be changed by this option in qemu-kvm is now the default
 when using the KVM PIT. It still can be requested explicitly using
 ``-global kvm-pit.lost_tick_policy=delay``.
 
+``-drive secs=s``, ``-drive heads=h`` & ``-drive cyls=c`` (removed in 3.0)
+''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
+
+The drive geometry should now be specified via
+``-device ...,drive=dr,cyls=c,heads=h,secs=s`` (together with
+``-drive if=none,id=dr,...``).
+
+``-drive serial=``, ``-drive trans=`` & ``-drive addr=`` (removed in 3.0)
+'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
+
+Use ``-device ...,drive=dr,serial=r,bios-chs-trans=t,addr=a`` instead
+(together with ``-drive if=none,id=dr,...``).
+
+``-net ...,vlan=x`` (removed in 3.0)
+''''''''''''''''''''''''''''''''''''
+
+The term "vlan" was very confusing for most users in this context (it's about
+specifying a hub ID, not about IEEE 802.1Q or something similar), so this
+has been removed. To connect one NIC frontend with a network backend, either
+use ``-nic ...`` (e.g. for on-board NICs) or use ``-netdev ...,id=n`` together
+with ``-device ...,netdev=n`` (for full control over pluggable NICs). To
+connect multiple NICs or network backends via a hub device (which is what
+vlan did), use ``-nic hubport,hubid=x,...`` or
+``-netdev hubport,id=n,hubid=x,...`` (with ``-device ...,netdev=n``) instead.
+
+``-no-kvm-irqchip`` (removed in 3.0)
+''''''''''''''''''''''''''''''''''''
+
+Use ``-machine kernel_irqchip=off`` instead.
+
+``-no-kvm-pit-reinjection`` (removed in 3.0)
+''''''''''''''''''''''''''''''''''''''''''''
+
+Use ``-global kvm-pit.lost_tick_policy=discard`` instead.
+
 ``-net ...,name=...`` (removed in 5.1)
 ''''''''''''''''''''''''''''''''''''''
 
-- 
2.27.0