Re: [Qemu-devel] [PATCH] spapr: quantify error messages regarding capability settings

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

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On Thu, Aug 01, 2019 at 09:34:38AM +1000, Daniel Black wrote:
> Its not immediately obvious how cap-X=y setting need to be applied
> to the command line so this has been clarified to "appending to the
> machine name" in spapr capability error messages.
> 
> The wrong value messages have been left as is, as the user has found
> the right location.

Good idea, but I think it would be easier to follow if you just said
	"try -machine cap-whatever=on"
It's permitted to have multiple -machine options, so that works even
if you are currently using the default machine type.

> 
> Signed-off-by: Daniel Black <daniel@linux.ibm.com>
> ---
>  hw/ppc/spapr_caps.c | 47 ++++++++++++++++++++++++++++++---------------
>  1 file changed, 32 insertions(+), 15 deletions(-)
> 
> diff --git a/hw/ppc/spapr_caps.c b/hw/ppc/spapr_caps.c
> index bbb001f84a..cf334fe595 100644
> --- a/hw/ppc/spapr_caps.c
> +++ b/hw/ppc/spapr_caps.c
> @@ -37,6 +37,8 @@
>  
>  #include "hw/ppc/spapr.h"
>  
> +#define CAPABILITY_ERROR(X) "appending \"," X "\" to the machine name"
> +
>  typedef struct SpaprCapPossible {
>      int num;            /* size of vals array below */
>      const char *help;   /* help text for vals */
> @@ -194,10 +196,12 @@ static void cap_htm_apply(SpaprMachineState *spapr, uint8_t val, Error **errp)
>      }
>      if (tcg_enabled()) {
>          error_setg(errp,
> -                   "No Transactional Memory support in TCG, try cap-htm=off");
> +                   "No Transactional Memory support in TCG, try "
> +                   CAPABILITY_ERROR("cap-htm=off"));
>      } else if (kvm_enabled() && !kvmppc_has_cap_htm()) {
>          error_setg(errp,
> -"KVM implementation does not support Transactional Memory, try cap-htm=off"
> +"KVM implementation does not support Transactional Memory, try "
> +                   CAPABILITY_ERROR("cap-htm=off")
>              );
>      }
>  }
> @@ -215,7 +219,8 @@ static void cap_vsx_apply(SpaprMachineState *spapr, uint8_t val, Error **errp)
>       * rid of anything that doesn't do VMX */
>      g_assert(env->insns_flags & PPC_ALTIVEC);
>      if (!(env->insns_flags2 & PPC2_VSX)) {
> -        error_setg(errp, "VSX support not available, try cap-vsx=off");
> +        error_setg(errp, "VSX support not available, try "
> +                   CAPABILITY_ERROR("cap-vsx=off"));
>      }
>  }
>  
> @@ -229,7 +234,8 @@ static void cap_dfp_apply(SpaprMachineState *spapr, uint8_t val, Error **errp)
>          return;
>      }
>      if (!(env->insns_flags2 & PPC2_DFP)) {
> -        error_setg(errp, "DFP support not available, try cap-dfp=off");
> +        error_setg(errp, "DFP support not available, try "
> +                   CAPABILITY_ERROR("cap-dfp=off"));
>      }
>  }
>  
> @@ -249,11 +255,13 @@ static void cap_safe_cache_apply(SpaprMachineState *spapr, uint8_t val,
>      if (tcg_enabled() && val) {
>          /* TCG only supports broken, allow other values and print a warning */
>          error_setg(&local_err,
> -                   "TCG doesn't support requested feature, cap-cfpc=%s",
> +                   "TCG doesn't support requested feature, use "
> +                   CAPABILITY_ERROR("cap-cfpc=%s"),
>                     cap_cfpc_possible.vals[val]);
>      } else if (kvm_enabled() && (val > kvm_val)) {
>          error_setg(errp,
> -"Requested safe cache capability level not supported by kvm, try cap-cfpc=%s",
> +"Requested safe cache capability level not supported by kvm, try "
> +                   CAPABILITY_ERROR("cap-cfpc=%s"),
>                     cap_cfpc_possible.vals[kvm_val]);
>      }
>  
> @@ -281,7 +289,8 @@ static void cap_safe_bounds_check_apply(SpaprMachineState *spapr, uint8_t val,
>                     cap_sbbc_possible.vals[val]);
>      } else if (kvm_enabled() && (val > kvm_val)) {
>          error_setg(errp,
> -"Requested safe bounds check capability level not supported by kvm, try cap-sbbc=%s",
> +"Requested safe bounds check capability level not supported by kvm, try "
> +                   CAPABILITY_ERROR("cap-sbbc=%s"),
>                     cap_sbbc_possible.vals[kvm_val]);
>      }
>  
> @@ -312,7 +321,8 @@ static void cap_safe_indirect_branch_apply(SpaprMachineState *spapr,
>                     cap_ibs_possible.vals[val]);
>      } else if (kvm_enabled() && (val > kvm_val)) {
>          error_setg(errp,
> -"Requested safe indirect branch capability level not supported by kvm, try cap-ibs=%s",
> +"Requested safe indirect branch capability level not supported by kvm, try "
> +                   CAPABILITY_ERROR("cap-ibs=%s"),
>                     cap_ibs_possible.vals[kvm_val]);
>      }
>  
> @@ -401,11 +411,13 @@ static void cap_nested_kvm_hv_apply(SpaprMachineState *spapr,
>  
>      if (tcg_enabled()) {
>          error_setg(errp,
> -                   "No Nested KVM-HV support in tcg, try cap-nested-hv=off");
> +                   "No Nested KVM-HV support in tcg, try "
> +                   CAPABILITY_ERROR("cap-nested-hv=off"));
>      } else if (kvm_enabled()) {
>          if (!kvmppc_has_cap_nested_kvm_hv()) {
>              error_setg(errp,
> -"KVM implementation does not support Nested KVM-HV, try cap-nested-hv=off");
> +"KVM implementation does not support Nested KVM-HV, try "
> +                       CAPABILITY_ERROR("cap-nested-hv=off"));
>          } else if (kvmppc_set_cap_nested_kvm_hv(val) < 0) {
>                  error_setg(errp,
>  "Error enabling cap-nested-hv with KVM, try cap-nested-hv=off");
> @@ -435,10 +447,12 @@ static void cap_large_decr_apply(SpaprMachineState *spapr,
>  
>          if (!kvm_nr_bits) {
>              error_setg(errp,
> -                       "No large decrementer support, try cap-large-decr=off");
> +                       "No large decrementer support, try "
> +                        CAPABILITY_ERROR("cap-large-decr=off"));
>          } else if (pcc->lrg_decr_bits != kvm_nr_bits) {
>              error_setg(errp,
> -"KVM large decrementer size (%d) differs to model (%d), try -cap-large-decr=off",
> +"KVM large decrementer size (%d) differs to model (%d), try "
> +                CAPABILITY_ERROR("cap-large-decr=off"),
>                  kvm_nr_bits, pcc->lrg_decr_bits);
>          }
>      }
> @@ -454,7 +468,8 @@ static void cap_large_decr_cpu_apply(SpaprMachineState *spapr,
>      if (kvm_enabled()) {
>          if (kvmppc_enable_cap_large_decr(cpu, val)) {
>              error_setg(errp,
> -                       "No large decrementer support, try cap-large-decr=off");
> +                       "No large decrementer support, try "
> +                       CAPABILITY_ERROR("cap-large-decr=off"));
>          }
>      }
>  
> @@ -474,10 +489,12 @@ static void cap_ccf_assist_apply(SpaprMachineState *spapr, uint8_t val,
>      if (tcg_enabled() && val) {
>          /* TODO - for now only allow broken for TCG */
>          error_setg(errp,
> -"Requested count cache flush assist capability level not supported by tcg, try cap-ccf-assist=off");
> +"Requested count cache flush assist capability level not supported by tcg, try "
> +                   CAPABILITY_ERROR("cap-ccf-assist=off"));
>      } else if (kvm_enabled() && (val > kvm_val)) {
>          error_setg(errp,
> -"Requested count cache flush assist capability level not supported by kvm, try cap-ccf-assist=off");
> +"Requested count cache flush assist capability level not supported by kvm, try "
> +                   CAPABILITY_ERROR("cap-ccf-assist=off"));
>      }
>  }
>  

-- 
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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