Re: [PATCH] hw/arm: add versioning to sbsa-ref machine DT

[Cédric Le Goater]

On 4/27/22 20:29, Leif Lindholm wrote:
> The sbsa-ref machine is continuously evolving. Some of the changes we
> want to make in the near future, to align with real components (e.g.
> the GIC-700), will break compatibility for existing firmware.
>
> Introduce two new properties to the DT generated on machine generation:
> - machine-version-major
>    To be incremented when a platform change makes the machine
>    incompatible with existing firmware.
> - machine-version-minor
>    To be incremented when functionality is added to the machine
>    without causing incompatibility with existing firmware.
>    to be reset to 0 when machine-version-major is incremented.
>
> These properties are both introduced with the value 0.
> (Hence, a machine where the DT is lacking these nodes is equivalent
> to version 0.0.)
>
> Signed-off-by: Leif Lindholm <quic_llindhol@quicinc.com>
> Cc: Peter Maydell <peter.maydell@linaro.org>
> Cc: Radoslaw Biernacki <rad@semihalf.com>
> Cc: Cédric Le Goater <clg@kaod.org>
> ---
>   hw/arm/sbsa-ref.c | 3 +++
>   1 file changed, 3 insertions(+)
>
> diff --git a/hw/arm/sbsa-ref.c b/hw/arm/sbsa-ref.c
> index 2387401963..e05f6056c7 100644
> --- a/hw/arm/sbsa-ref.c
> +++ b/hw/arm/sbsa-ref.c
> @@ -190,6 +190,9 @@ static void create_fdt(SBSAMachineState *sms)
>       qemu_fdt_setprop_cell(fdt, "/", "#address-cells", 0x2);
>       qemu_fdt_setprop_cell(fdt, "/", "#size-cells", 0x2);
>   
> +    qemu_fdt_setprop_cell(fdt, "/", "machine-version-major", 0);
> +    qemu_fdt_setprop_cell(fdt, "/", "machine-version-minor", 0);


Thanks for your reply in the other email. From what I captured, the
DT aspect is not that important, but still, we could may be use some
specific 'sbsa' property names :

    qemu_fdt_setprop_cell(fdt, "/", "sbsa,version-major", 0);
    qemu_fdt_setprop_cell(fdt, "/", "sbsa,version-minor", 0);


?

C.

> +
>       if (ms->numa_state->have_numa_distance) {
>           int size = nb_numa_nodes * nb_numa_nodes * 3 * sizeof(uint32_t);
>           uint32_t *matrix = g_malloc0(size);