Re: [PATCH 04/13] ppc/spapr: Remove copy-paste from pa-features

[Harsh Prateek Bora <harshpb@linux.ibm.com>]

Hi Nick,

On 3/12/24 00:21, Nicholas Piggin wrote:
> TCG does not support copy/paste instructions. Remove it from
> ibm,pa-features. This has never been implemented under TCG or

s/or/nor ?

> practically usable under KVM, so it won't be missed.
> 
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---
>   hw/ppc/spapr.c | 8 ++++++--
>   1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index 5099f12cc6..7d7da30f60 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -254,8 +254,8 @@ static void spapr_dt_pa_features(SpaprMachineState *spapr,
>           0x80, 0x00, 0x80, 0x00, 0x80, 0x00, /* 24 - 29 */
>           /* 30: MMR, 32: LE atomic, 34: EBB + ext EBB */
>           0x80, 0x00, 0x80, 0x00, 0xC0, 0x00, /* 30 - 35 */
> -        /* 36: SPR SO, 38: Copy/Paste, 40: Radix MMU */
> -        0x80, 0x00, 0x80, 0x00, 0x80, 0x00, /* 36 - 41 */
> +        /* 36: SPR SO, 40: Radix MMU */
> +        0x80, 0x00, 0x00, 0x00, 0x80, 0x00, /* 36 - 41 */
>           /* 42: PM, 44: PC RA, 46: SC vec'd */
>           0x80, 0x00, 0x80, 0x00, 0x80, 0x00, /* 42 - 47 */
>           /* 48: SIMD, 50: QP BFP, 52: String */
> @@ -288,6 +288,10 @@ static void spapr_dt_pa_features(SpaprMachineState *spapr,
>        * SSO (SAO) ordering is supported on KVM and thread=single hosts,
>        * but not MTTCG, so disable it. To advertise it, a cap would have
>        * to be added, or support implemented for MTTCG.
> +     *
> +     * Copy/paste is not supported by TCG, so it is not advertised. KVM
> +     * can execute them but it has no accelerator drivers which are usable,
> +     * so there isn't much need for it anyway.
>        */

If doing a re-spin, you may consider comments on prev patch applicable
above as well. Either ways, with prev typo fixed:

Reviewed-by: Harsh Prateek Bora <harshpb@linux.ibm.com>

>   
>       if (ppc_hash64_has(cpu, PPC_HASH64_CI_LARGEPAGE)) {