Re: [Qemu-devel] [PATCH] spapr: Add H-Call H_HOME_NODE_ASSOCIATIVITY

[David Gibson <david@gibson.dropbear.id.au>]

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On Mon, Dec 17, 2018 at 03:00:55PM +0100, Laurent Vivier wrote:
> H_HOME_NODE_ASSOCIATIVITY H-Call returns the associativity domain
> designation associated with the identifier input parameter.
> 
> Remove the warning message from the kernel:
>   VPHN is not supported. Disabling polling..
> 
> Signed-off-by: Laurent Vivier <lvivier@redhat.com>

From the looks of PAPR, I suspect this call isn't of much use outside
PowerVM guests, though it probably wouldn't do any harm.

BenH, Paulus, any thoughts?

One nit in implementation: if you implement this hcall, it's supposed
to be advertised by adding hcall-vphn to ibm,hypertas-functions.

> ---
> Based-on: <20181213040126.6768-1-david@gibson.dropbear.id.au>
>           "[PULL 00/27] ppc-for-4.0 queue 20181213"
> 
>  hw/ppc/spapr_hcall.c   | 39 +++++++++++++++++++++++++++++++++++++++
>  include/hw/ppc/spapr.h |  1 +
>  2 files changed, 40 insertions(+)
> 
> diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c
> index 78fecc8fe9..454ec594fd 100644
> --- a/hw/ppc/spapr_hcall.c
> +++ b/hw/ppc/spapr_hcall.c
> @@ -1663,6 +1663,41 @@ static target_ulong h_client_architecture_support(PowerPCCPU *cpu,
>      return H_SUCCESS;
>  }
>  
> +static target_ulong h_home_node_associativity(PowerPCCPU *cpu,
> +                                              sPAPRMachineState *spapr,
> +                                              target_ulong opcode,
> +                                              target_ulong *args)
> +{
> +    target_ulong flags = args[0];
> +    target_ulong procno = args[1];
> +    PowerPCCPU *tcpu;
> +    int idx;
> +
> +    /* only support procno from H_REGISTER_VPA */
> +    if ((flags & 0x1) == 0) {
> +        return H_PARAMETER;
> +    }
> +
> +    tcpu = spapr_find_cpu(procno);
> +    if (tcpu == NULL) {
> +        return H_P2;
> +    }
> +
> +    /* sequence is the same as in the "ibm,associativity" property */
> +
> +    idx = 0;
> +#define ASSOCIATIVITY(a, b) (((uint64_t)a << 32) | ((uint64_t)b & 0xffffffff))
> +    args[idx++] = ASSOCIATIVITY(0, 0);
> +    args[idx++] = ASSOCIATIVITY(0, tcpu->node_id);
> +    args[idx++] = ASSOCIATIVITY(procno, -1);
> +    for ( ; idx < 6; idx++) {
> +        args[idx] = -1;
> +    }
> +#undef ASSOCIATIVITY
> +
> +    return H_SUCCESS;
> +}
> +
>  static target_ulong h_get_cpu_characteristics(PowerPCCPU *cpu,
>                                                sPAPRMachineState *spapr,
>                                                target_ulong opcode,
> @@ -1864,6 +1899,10 @@ static void hypercall_register_types(void)
>      spapr_register_hypercall(KVMPPC_H_CAS, h_client_architecture_support);
>  
>      spapr_register_hypercall(KVMPPC_H_UPDATE_DT, h_update_dt);
> +
> +    /* Virtual Processor Home Node */
> +    spapr_register_hypercall(H_HOME_NODE_ASSOCIATIVITY,
> +                             h_home_node_associativity);
>  }
>  
>  type_init(hypercall_register_types)
> diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
> index b1a2515107..eb13e2b614 100644
> --- a/include/hw/ppc/spapr.h
> +++ b/include/hw/ppc/spapr.h
> @@ -447,6 +447,7 @@ struct sPAPRMachineState {
>  #define H_GET_EM_PARMS          0x2B8
>  #define H_SET_MPP               0x2D0
>  #define H_GET_MPP               0x2D4
> +#define H_HOME_NODE_ASSOCIATIVITY 0x2EC
>  #define H_XIRR_X                0x2FC
>  #define H_RANDOM                0x300
>  #define H_SET_MODE              0x31C

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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