On Sun, 22 Jun 2025 at 00:55, Richard Henderson
<richard.hender...@linaro.org> wrote:
>
> This is a 512-bit array introduced with SME2.
> Save it only when ZA is in use.
>
> Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
> ---
> target/arm/cpu.h | 3 +++
> target/arm/machine.c | 20 ++++++++++++++++++++
> 2 files changed, 23 insertions(+)
>
> diff --git a/target/arm/cpu.h b/target/arm/cpu.h
> index 052ca20283..465fc188d0 100644
> --- a/target/arm/cpu.h
> +++ b/target/arm/cpu.h
> @@ -715,6 +715,9 @@ typedef struct CPUArchState {
> uint64_t scxtnum_el[4];
>
> struct {
> + /* SME2 ZT0 -- 512 bit array, with data ordered like ARMVectorReg. */
> + uint64_t zt0[512 / 64] QEMU_ALIGNED(16);
> +
> /*
> * SME ZA storage -- 256 x 256 byte array, with bytes in host
> * word order, as we do with vfp.zregs[]. This corresponds to
> diff --git a/target/arm/machine.c b/target/arm/machine.c
> index 6e73368ef9..6986915bee 100644
> --- a/target/arm/machine.c
> +++ b/target/arm/machine.c
> @@ -321,6 +321,25 @@ static const VMStateDescription vmstate_za = {
> }
> };
>
> +static bool zt0_needed(void *opaque)
> +{
> + ARMCPU *cpu = opaque;
> +
> + return za_needed(cpu) && cpu_isar_feature(aa64_sme2, cpu);
> +}
> +
> +static const VMStateDescription vmstate_zt0 = {
> + .name = "cpu/zt0",
> + .version_id = 1,
> + .minimum_version_id = 1,
> + .needed = zt0_needed,
> + .fields = (VMStateField[]) {
> + VMSTATE_UINT64_ARRAY(env.za_state.zt0, ARMCPU,
> + ARRAY_SIZE(((CPUARMState *)0)->za_state.zt0)),
> + VMSTATE_END_OF_LIST()
> + }
> +};
I wonder if we should have an ARRAY_FIELD_SIZE(), to do
the equivalent of sizeof_field()... Though we have no
uses of the written-out form currently, so it might be
a bit too niche.
Anyway
Reviewed-by: Peter Maydell <peter.mayd...@linaro.org>
thanks
-- PMM
