Re: [PATCH v2 1/2] kvm: replace fprintf with error_report() in kvm_init() for error conditions

[Ani Sinha]

On Fri, Aug 9, 2024 at 11:27 AM Zhao Liu <zhao1.liu@intel.com> wrote:
>
> On Fri, Aug 09, 2024 at 10:40:53AM +0530, Ani Sinha wrote:
> > Date: Fri,  9 Aug 2024 10:40:53 +0530
> > From: Ani Sinha <anisinha@redhat.com>
> > Subject: [PATCH v2 1/2] kvm: replace fprintf with error_report() in
> >  kvm_init() for error conditions
> > X-Mailer: git-send-email 2.45.2
> >
> > error_report() is more appropriate for error situations. Replace fprintf 
> > with
> > error_report. Cosmetic. No functional change.
> >
> > CC: qemu-trivial@nongnu.org
> > CC: zhao1.liu@intel.com
> > Signed-off-by: Ani Sinha <anisinha@redhat.com>
> > ---
> >  accel/kvm/kvm-all.c | 40 ++++++++++++++++++----------------------
> >  1 file changed, 18 insertions(+), 22 deletions(-)
> >
> > changelog:
> > v2: fix a bug.
>
> Generally good to me. Only some nits below, otherwise,
>
> Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
>
> >  #ifdef TARGET_S390X
> >          if (ret == -EINVAL) {
> > -            fprintf(stderr,
> > -                    "Host kernel setup problem detected. Please 
> > verify:\n");
> > -            fprintf(stderr, "- for kernels supporting the switch_amode or"
> > -                    " user_mode parameters, whether\n");
> > -            fprintf(stderr,
> > -                    "  user space is running in primary address space\n");
> > -            fprintf(stderr,
> > -                    "- for kernels supporting the vm.allocate_pgste 
> > sysctl, "
> > -                    "whether it is enabled\n");
> > +            error_report("Host kernel setup problem detected. Please 
> > verify:");
>
> The doc of error_report() said it doesn't want multiple sentences or trailing
> punctuation:
>
> "The resulting message should be a single phrase, with no newline or trailing
> punctuation."
>
> So I think these extra messages (with complex formatting & content) are
> better printed with error_printf() as I suggested in [1].
>
> [1]: 
> ZrWP0fWPNzeAvjja@intel.com/T/#m953afd879eb6279fcdf03cda594c43f1829bdffe">https://lore.kernel.org/qemu-devel/ZrWP0fWPNzeAvjja@intel.com/T/#m953afd879eb6279fcdf03cda594c43f1829bdffe
>
> > +            error_report("- for kernels supporting the switch_amode or"
> > +                        " user_mode parameters, whether");
> > +            error_report("  user space is running in primary address 
> > space");
> > +            error_report("- for kernels supporting the vm.allocate_pgste "
> > +                        "sysctl, whether it is enabled");
> >          }
> >  #elif defined(TARGET_PPC)
> >          if (ret == -EINVAL) {
> > -            fprintf(stderr,
> > -                    "PPC KVM module is not loaded. Try modprobe kvm_%s.\n",
> > -                    (type == 2) ? "pr" : "hv");
> > +            error_report("PPC KVM module is not loaded. Try modprobe 
> > kvm_%s.",
> > +                        (type == 2) ? "pr" : "hv");
>
> Same here. A trailing punctuation. If possible, feel free to refer to
> the comment in [1].

vreport() adds a training newline, so I think its ok to remove the
training newline and replace with error_report().

>
> >          }
> >  #endif
>
> [snip]
>
> > @@ -2542,8 +2538,8 @@ static int kvm_init(MachineState *ms)
> >      }
> >      if (missing_cap) {
> >          ret = -EINVAL;
> > -        fprintf(stderr, "kvm does not support %s\n%s",
> > -                missing_cap->name, upgrade_note);
> > +        error_report("kvm does not support %s", missing_cap->name);
> > +        error_report("%s", upgrade_note);
>
> "upgrade_note" string also has the trailing punctuation, and it's
> also better to use error_printf() to replace the 2nd error_report().

Yes this looks ugly and I will replace this one with error_printf()

>
> For this patch, error_report() is already a big step forward, so I think
> these few nits doesn't block this patch.

Thanks but I will send another version with your tag added.

>
> Thank you for your patience.
> Zhao
>