They are older than 6 years, so according to our machine support
policy, they can be removed now.

This removes the requirements for the storage keys "migration-enabled"
property which will be removed in the next patch. It also removes
the code that sets "max_revision" to 0 for some CCW devices, but
the relating code in virtio-ccw.c indicates that 0 could have also
been in use for other machines types < 5.1, so further clean-up for
code related to "max_revision" won't be done yet.

Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 hw/s390x/s390-virtio-ccw.c | 37 -------------------------------------
 1 file changed, 37 deletions(-)

diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
index 2be8da2913..bca61488cc 100644
--- a/hw/s390x/s390-virtio-ccw.c
+++ b/hw/s390x/s390-virtio-ccw.c
@@ -1325,43 +1325,6 @@ static void ccw_machine_2_6_class_options(MachineClass *mc)
 }
 DEFINE_CCW_MACHINE(2, 6);
 
-static void ccw_machine_2_5_instance_options(MachineState *machine)
-{
-    ccw_machine_2_6_instance_options(machine);
-}
-
-static void ccw_machine_2_5_class_options(MachineClass *mc)
-{
-    ccw_machine_2_6_class_options(mc);
-    compat_props_add(mc->compat_props, hw_compat_2_5, hw_compat_2_5_len);
-}
-DEFINE_CCW_MACHINE(2, 5);
-
-static void ccw_machine_2_4_instance_options(MachineState *machine)
-{
-    ccw_machine_2_5_instance_options(machine);
-}
-
-static void ccw_machine_2_4_class_options(MachineClass *mc)
-{
-    static GlobalProperty compat[] = {
-        { TYPE_S390_SKEYS, "migration-enabled", "off", },
-        { "virtio-blk-ccw", "max_revision", "0", },
-        { "virtio-balloon-ccw", "max_revision", "0", },
-        { "virtio-serial-ccw", "max_revision", "0", },
-        { "virtio-9p-ccw", "max_revision", "0", },
-        { "virtio-rng-ccw", "max_revision", "0", },
-        { "virtio-net-ccw", "max_revision", "0", },
-        { "virtio-scsi-ccw", "max_revision", "0", },
-        { "vhost-scsi-ccw", "max_revision", "0", },
-    };
-
-    ccw_machine_2_5_class_options(mc);
-    compat_props_add(mc->compat_props, hw_compat_2_4, hw_compat_2_4_len);
-    compat_props_add(mc->compat_props, compat, G_N_ELEMENTS(compat));
-}
-DEFINE_CCW_MACHINE(2, 4);
-
 #endif
 
 static void ccw_machine_register_types(void)
-- 
2.47.1

On Fri, Jan 03 2025, Thomas Huth <thuth@redhat.com> wrote:

> They are older than 6 years, so according to our machine support
> policy, they can be removed now.
>
> This removes the requirements for the storage keys "migration-enabled"
> property which will be removed in the next patch. It also removes
> the code that sets "max_revision" to 0 for some CCW devices, but
> the relating code in virtio-ccw.c indicates that 0 could have also
> been in use for other machines types < 5.1, so further clean-up for
> code related to "max_revision" won't be done yet.

These are two different issues:
- QEMU 2.4 and earlier _defaulted_ to legacy virtio devices (enforced by
  setting max_revision to 0)
- QEMU 5.0 and earlier _allowed_ virtio device types to be configured as
  legacy devices that did not actually support legacy (e.g. virtio-gpu),
  there's a compat value to allow a max_revision of 0 for those old
  machine types

So that's not a problem -- but I wonder whether we had missed the boat
elsewhere, when we introduced revisions > 1 (nothing much we can do now
if that is the case, though.)

I also don't think we actually want to remove max_revision anyway, as it
could also be used for non-compat related things (e.g. to accommodate a
known buggy driver.)

>
> Signed-off-by: Thomas Huth <thuth@redhat.com>
> ---
>  hw/s390x/s390-virtio-ccw.c | 37 -------------------------------------
>  1 file changed, 37 deletions(-)

The patch itself LGTM.

On 3/1/25 15:42, Thomas Huth wrote:
> They are older than 6 years, so according to our machine support
> policy, they can be removed now.
> 
> This removes the requirements for the storage keys "migration-enabled"
> property which will be removed in the next patch. It also removes
> the code that sets "max_revision" to 0 for some CCW devices, but
> the relating code in virtio-ccw.c indicates that 0 could have also
> been in use for other machines types < 5.1, so further clean-up for
> code related to "max_revision" won't be done yet.

Please mention commit d55f518248f ("virtio: skip legacy support check
on machine types less than 5.1")

> 
> Signed-off-by: Thomas Huth <thuth@redhat.com>
> ---
>   hw/s390x/s390-virtio-ccw.c | 37 -------------------------------------
>   1 file changed, 37 deletions(-)

Tested-by: Philippe Mathieu-Daudé <philmd@linaro.org>

On 7/1/25 12:03, Philippe Mathieu-Daudé wrote:
> On 3/1/25 15:42, Thomas Huth wrote:
>> They are older than 6 years, so according to our machine support
>> policy, they can be removed now.
>>
>> This removes the requirements for the storage keys "migration-enabled"
>> property which will be removed in the next patch. It also removes
>> the code that sets "max_revision" to 0 for some CCW devices, but
>> the relating code in virtio-ccw.c indicates that 0 could have also
>> been in use for other machines types < 5.1, so further clean-up for
>> code related to "max_revision" won't be done yet.
> 
> Please mention commit d55f518248f ("virtio: skip legacy support check
> on machine types less than 5.1")

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

> 
>>
>> Signed-off-by: Thomas Huth <thuth@redhat.com>
>> ---
>>   hw/s390x/s390-virtio-ccw.c | 37 -------------------------------------
>>   1 file changed, 37 deletions(-)
> 
> Tested-by: Philippe Mathieu-Daudé <philmd@linaro.org>