| Message ID | 20231129042012.277831-2-gshan@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Unified CPU type check | expand |
Gavin Shan <gshan@redhat.com> writes: > QEMU will be terminated if the specified CPU type isn't supported > in machine_run_board_init(). The list of supported CPU type names > is tracked by mc->valid_cpu_types. Suggest to drop the second sentence. > The error handling can be used to propagate error messages, to be > consistent how the errors are handled for other situations in the > same function. > > No functional change intended. > > Suggested-by: Igor Mammedov <imammedo@redhat.com> > Signed-off-by: Gavin Shan <gshan@redhat.com> > --- > v8: Drop @local_err and use @errp to be compatible with > ERRP_GUARD() (Phil) > --- > hw/core/machine.c | 13 +++++++------ > 1 file changed, 7 insertions(+), 6 deletions(-) > > diff --git a/hw/core/machine.c b/hw/core/machine.c > index 0c17398141..bde7f4af6d 100644 > --- a/hw/core/machine.c > +++ b/hw/core/machine.c > @@ -1466,15 +1466,16 @@ void machine_run_board_init(MachineState *machine, const char *mem_path, Error * > > if (!machine_class->valid_cpu_types[i]) { > /* The user specified CPU is not valid */ > - error_report("Invalid CPU type: %s", machine->cpu_type); > - error_printf("The valid types are: %s", > - machine_class->valid_cpu_types[0]); > + error_setg(errp, "Invalid CPU type: %s", machine->cpu_type); > + error_append_hint(errp, "The valid types are: %s", > + machine_class->valid_cpu_types[0]); > for (i = 1; machine_class->valid_cpu_types[i]; i++) { > - error_printf(", %s", machine_class->valid_cpu_types[i]); > + error_append_hint(errp, ", %s", > + machine_class->valid_cpu_types[i]); > } > - error_printf("\n"); > > - exit(1); > + error_append_hint(&errp, "\n"); > + return; > } > } This cleans up an anti-pattern: use of error_report() within a function that returns errors through an Error **errp parameter. Cleanup, not bug fix, because the only caller passes &error_abort. Suggest to start the commit message with a mention of the anti-pattern. Here's how I'd write it: Functions that use an Error **errp parameter to return errors should not also report them to the user, because reporting is the caller's job. machine_run_board_init() violates this principle: it calls error_report(), error_printf(), and exit(1) when the machine doesn't support the requested CPU type. Clean this up by using error_setg() and error_append_hint() instead. No functional change, as the only caller passes &error_fatal. Whether you use my suggestion or not: Reviewed-by: Markus Armbruster <armbru@redhat.com>
Hi Markus, On 11/29/23 19:20, Markus Armbruster wrote: > Gavin Shan <gshan@redhat.com> writes: > >> QEMU will be terminated if the specified CPU type isn't supported >> in machine_run_board_init(). The list of supported CPU type names >> is tracked by mc->valid_cpu_types. > > Suggest to drop the second sentence. > Indeed, it's not so helpful. >> The error handling can be used to propagate error messages, to be >> consistent how the errors are handled for other situations in the >> same function. >> >> No functional change intended. >> >> Suggested-by: Igor Mammedov <imammedo@redhat.com> >> Signed-off-by: Gavin Shan <gshan@redhat.com> >> --- >> v8: Drop @local_err and use @errp to be compatible with >> ERRP_GUARD() (Phil) >> --- >> hw/core/machine.c | 13 +++++++------ >> 1 file changed, 7 insertions(+), 6 deletions(-) >> >> diff --git a/hw/core/machine.c b/hw/core/machine.c >> index 0c17398141..bde7f4af6d 100644 >> --- a/hw/core/machine.c >> +++ b/hw/core/machine.c >> @@ -1466,15 +1466,16 @@ void machine_run_board_init(MachineState *machine, const char *mem_path, Error * >> >> if (!machine_class->valid_cpu_types[i]) { >> /* The user specified CPU is not valid */ >> - error_report("Invalid CPU type: %s", machine->cpu_type); >> - error_printf("The valid types are: %s", >> - machine_class->valid_cpu_types[0]); >> + error_setg(errp, "Invalid CPU type: %s", machine->cpu_type); >> + error_append_hint(errp, "The valid types are: %s", >> + machine_class->valid_cpu_types[0]); >> for (i = 1; machine_class->valid_cpu_types[i]; i++) { >> - error_printf(", %s", machine_class->valid_cpu_types[i]); >> + error_append_hint(errp, ", %s", >> + machine_class->valid_cpu_types[i]); >> } >> - error_printf("\n"); >> >> - exit(1); >> + error_append_hint(&errp, "\n"); >> + return; >> } >> } > > This cleans up an anti-pattern: use of error_report() within a function that > returns errors through an Error **errp parameter. > > Cleanup, not bug fix, because the only caller passes &error_abort. > > Suggest to start the commit message with a mention of the anti-pattern. > Here's how I'd write it: > > Functions that use an Error **errp parameter to return errors should > not also report them to the user, because reporting is the caller's > job. > > machine_run_board_init() violates this principle: it calls > error_report(), error_printf(), and exit(1) when the machine doesn't > support the requested CPU type. > > Clean this up by using error_setg() and error_append_hint() instead. > No functional change, as the only caller passes &error_fatal. > Thanks for the nice write-up. I will take it if v9 is needed to address comments from other people. > Whether you use my suggestion or not: > Reviewed-by: Markus Armbruster <armbru@redhat.com> > Thanks for your review. Thanks, Gavin
diff --git a/hw/core/machine.c b/hw/core/machine.c index 0c17398141..bde7f4af6d 100644 --- a/hw/core/machine.c +++ b/hw/core/machine.c @@ -1466,15 +1466,16 @@ void machine_run_board_init(MachineState *machine, const char *mem_path, Error * if (!machine_class->valid_cpu_types[i]) { /* The user specified CPU is not valid */ - error_report("Invalid CPU type: %s", machine->cpu_type); - error_printf("The valid types are: %s", - machine_class->valid_cpu_types[0]); + error_setg(errp, "Invalid CPU type: %s", machine->cpu_type); + error_append_hint(errp, "The valid types are: %s", + machine_class->valid_cpu_types[0]); for (i = 1; machine_class->valid_cpu_types[i]; i++) { - error_printf(", %s", machine_class->valid_cpu_types[i]); + error_append_hint(errp, ", %s", + machine_class->valid_cpu_types[i]); } - error_printf("\n"); - exit(1); + error_append_hint(&errp, "\n"); + return; } }
QEMU will be terminated if the specified CPU type isn't supported in machine_run_board_init(). The list of supported CPU type names is tracked by mc->valid_cpu_types. The error handling can be used to propagate error messages, to be consistent how the errors are handled for other situations in the same function. No functional change intended. Suggested-by: Igor Mammedov <imammedo@redhat.com> Signed-off-by: Gavin Shan <gshan@redhat.com> --- v8: Drop @local_err and use @errp to be compatible with ERRP_GUARD() (Phil) --- hw/core/machine.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-)