Re: [PATCH 4/9] x86/mwait-idle: Add Meteorlake support

[Alex Zero <alex.x.zero@xxxxxxxxxx>]

Reviewed-by: Alex XZ Cypher Zero <me@xxxxxxxxx>

> Add intel_idle support for MeteorLake.
>
> C1 and C1E states on Meteorlake are mutually exclusive, like Alderlake
> and Raptorlake, but they have little latency difference with measureable
> power difference, so always enable "C1E promotion" bit and expose C1E
> only.
>
> Expose C6 because it has less power compared with C1E, and smaller
> latency compared with C8/C10.
>
> Ignore C8 and expose C10, because C8 does not show latency advantage
> compared with C10.
>
> Signed-off-by: Zhang Rui <rui.zhang@xxxxxxxxx>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> Origin: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 
> eeae55ed9c0a
> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
>
> --- a/xen/arch/x86/cpu/mwait-idle.c
> +++ b/xen/arch/x86/cpu/mwait-idle.c
> @@ -678,6 +678,28 @@ static struct cpuidle_state __ro_after_i
>         {}
>   };
>   
> +static const struct cpuidle_state mtl_l_cstates[] = {
> +       {
> +               .name = "C1E",
> +               .flags = MWAIT2flg(0x01),
> +               .exit_latency = 1,
> +               .target_residency = 1,
> +       },
> +       {
> +               .name = "C6",
> +               .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
> +               .exit_latency = 140,
> +               .target_residency = 420,
> +       },
> +       {
> +               .name = "C10",
> +               .flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
> +               .exit_latency = 310,
> +               .target_residency = 930,
> +       },
> +       {}
> +};
> +
>   static const struct cpuidle_state gmt_cstates[] = {
>         {
>                 .name = "C1",
> @@ -1117,6 +1139,10 @@ static struct idle_cpu __ro_after_init i
>         .state_table = adl_l_cstates,
>   };
>   
> +static const struct idle_cpu idle_cpu_mtl_l = {
> +       .state_table = mtl_l_cstates,
> +};
> +
>   static const struct idle_cpu idle_cpu_gmt = {
>         .state_table = gmt_cstates,
>   };
> @@ -1186,6 +1212,7 @@ static const struct x86_cpu_id intel_idl
>         ICPU(ICELAKE_D,                 icx),
>         ICPU(ALDERLAKE,                 adl),
>         ICPU(ALDERLAKE_L,               adl_l),
> +       ICPU(METEORLAKE_L,              mtl_l),
>         ICPU(ATOM_GRACEMONT,            gmt),
>         ICPU(SAPPHIRERAPIDS_X,          spr),
>         ICPU(EMERALDRAPIDS_X,           spr),