On 4/30/24 11:45, Daniel P. Berrangé wrote:
On Tue, Apr 30, 2024 at 08:45:29AM +0200, Thomas Huth wrote:
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.
If anyone thinks 6 years is not very long, consider that this implies QEMU will be maintaining *18* versions for each versioned machine type.
So across aarch64 'virt', x86 'pc' & 'q35', ppc 'spapr', s390x 'ccw', and m68k 'virt', that's upto 108 machines we're keeping ABI preserved for in the worst case...
We will probably have RISC-V machines to support also. Anyhow, 6 years looks good to me. Thanks, C.