Re: [Qemu-devel] [QEMU-PPC] [PATCH 10/13] target/ppc: Implement hcall H_TLB_INVALIDATE

[David Gibson]

On Fri, May 03, 2019 at 03:53:13PM +1000, Suraj Jitindar Singh wrote:
> The hcall H_TLB_INVALIDATE is used by a guest acting as a nested
> hypervisor to perform partition scoped tlb invalidation since these
> instructions are hypervisor privileged.
> 
> Check the arguments are valid and then invalidate the entire tlb since
> this is about all we can do in tcg.
> 
> Signed-off-by: Suraj Jitindar Singh <address@hidden>

Reviewed-by: David Gibson <address@hidden>

> ---
>  hw/ppc/spapr_hcall.c   | 28 ++++++++++++++++++++++++++++
>  include/hw/ppc/spapr.h |  3 ++-
>  2 files changed, 30 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c
> index 68f3282214..a84d5e2163 100644
> --- a/hw/ppc/spapr_hcall.c
> +++ b/hw/ppc/spapr_hcall.c
> @@ -2131,6 +2131,33 @@ void h_exit_nested(PowerPCCPU *cpu)
>      env->gpr[3] = trap;
>  }
>  
> +static target_ulong h_nested_tlb_invalidate(PowerPCCPU *cpu,
> +                                            SpaprMachineState *spapr,
> +                                            target_ulong opcode,
> +                                            target_ulong *args)
> +{
> +    target_ulong instr = args[0];
> +    target_ulong rbval = args[2];
> +    int r, ric, prs, is;
> +
> +    if (spapr_get_cap(spapr, SPAPR_CAP_NESTED_KVM_HV) == 0) {
> +        return H_FUNCTION;
> +    }
> +
> +    ric = (instr >> 18) & 0x3;
> +    prs = (instr >> 17) & 0x1;
> +    r = (instr >> 16) & 0x1;
> +    is = (rbval >> 10) & 0x3;
> +
> +    if ((!r) || (prs) || (ric == 3) || (is == 1) || ((!is) && (ric == 1 ||
> +                                                               ric == 2)))
> +        return H_PARAMETER;
> +
> +    /* Invalidate everything, not much else we can do */
> +    cpu->env.tlb_need_flush = TLB_NEED_GLOBAL_FLUSH | TLB_NEED_LOCAL_FLUSH;
> +    return H_SUCCESS;
> +}
> +
>  static spapr_hcall_fn papr_hypercall_table[(MAX_HCALL_OPCODE / 4) + 1];
>  static spapr_hcall_fn kvmppc_hypercall_table[KVMPPC_HCALL_MAX - 
> KVMPPC_HCALL_BASE + 1];
>  
> @@ -2240,6 +2267,7 @@ static void hypercall_register_types(void)
>      /* Platform-specific hcalls used for nested HV KVM */
>      spapr_register_hypercall(H_SET_PARTITION_TABLE, h_set_partition_table);
>      spapr_register_hypercall(H_ENTER_NESTED, h_enter_nested);
> +    spapr_register_hypercall(H_TLB_INVALIDATE, h_nested_tlb_invalidate);
>  
>      /* Virtual Processor Home Node */
>      spapr_register_hypercall(H_HOME_NODE_ASSOCIATIVITY,
> diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
> index 7083dea9ef..6a614c445f 100644
> --- a/include/hw/ppc/spapr.h
> +++ b/include/hw/ppc/spapr.h
> @@ -504,7 +504,8 @@ struct SpaprMachineState {
>  /* Platform-specific hcalls used for nested HV KVM */
>  #define H_SET_PARTITION_TABLE   0xF800
>  #define H_ENTER_NESTED          0xF804
> -#define KVMPPC_HCALL_MAX        H_ENTER_NESTED
> +#define H_TLB_INVALIDATE        0xF808
> +#define KVMPPC_HCALL_MAX        H_TLB_INVALIDATE
>  
>  typedef struct SpaprDeviceTreeUpdateHeader {
>      uint32_t version_id;

-- 
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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