Re: [PATCH v3 1/9] target/i386: Restrict X86CPUFeatureWord to X86 targets

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

On 5/26/20 8:45 AM, Markus Armbruster wrote:
> Philippe Mathieu-Daudé <philmd@redhat.com> writes:
> 
>> Move out x86-specific structures from generic machine code.
>>
>> Acked-by: Richard Henderson <richard.henderson@linaro.org>
>> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
>> ---
>>  qapi/machine-target.json   | 45 ++++++++++++++++++++++++++++++++++++++
>>  qapi/machine.json          | 42 -----------------------------------
>>  target/i386/cpu.c          |  2 +-
>>  target/i386/machine-stub.c | 22 +++++++++++++++++++
>>  target/i386/Makefile.objs  |  3 ++-
>>  5 files changed, 70 insertions(+), 44 deletions(-)
>>  create mode 100644 target/i386/machine-stub.c
>>
>> diff --git a/qapi/machine-target.json b/qapi/machine-target.json
>> index f2c82949d8..fb7a4b7850 100644
>> --- a/qapi/machine-target.json
>> +++ b/qapi/machine-target.json
>> @@ -3,6 +3,51 @@
>>  # This work is licensed under the terms of the GNU GPL, version 2 or later.
>>  # See the COPYING file in the top-level directory.
>>  
>> +##
>> +# @X86CPURegister32:
>> +#
>> +# A X86 32-bit register
>> +#
>> +# Since: 1.5
>> +##
>> +{ 'enum': 'X86CPURegister32',
>> +  'data': [ 'EAX', 'EBX', 'ECX', 'EDX', 'ESP', 'EBP', 'ESI', 'EDI' ],
>> +  'if': 'defined(TARGET_I386)' }
>> +
>> +##
>> +# @X86CPUFeatureWordInfo:
>> +#
>> +# Information about a X86 CPU feature word
>> +#
>> +# @cpuid-input-eax: Input EAX value for CPUID instruction for that feature word
>> +#
>> +# @cpuid-input-ecx: Input ECX value for CPUID instruction for that
>> +#                   feature word
>> +#
>> +# @cpuid-register: Output register containing the feature bits
>> +#
>> +# @features: value of output register, containing the feature bits
>> +#
>> +# Since: 1.5
>> +##
>> +{ 'struct': 'X86CPUFeatureWordInfo',
>> +  'data': { 'cpuid-input-eax': 'int',
>> +            '*cpuid-input-ecx': 'int',
>> +            'cpuid-register': 'X86CPURegister32',
>> +            'features': 'int' },
>> +  'if': 'defined(TARGET_I386)' }
>> +
>> +##
>> +# @DummyForceArrays:
>> +#
>> +# Not used by QMP; hack to let us use X86CPUFeatureWordInfoList internally
>> +#
>> +# Since: 2.5
>> +##
>> +{ 'struct': 'DummyForceArrays',
>> +  'data': { 'unused': ['X86CPUFeatureWordInfo'] },
>> +  'if': 'defined(TARGET_I386)' }
>> +
>>  ##
>>  # @CpuModelInfo:
>>  #
>> diff --git a/qapi/machine.json b/qapi/machine.json
>> index ff7b5032e3..1fe31d374c 100644
>> --- a/qapi/machine.json
>> +++ b/qapi/machine.json
>> @@ -511,48 +511,6 @@
>>     'dst': 'uint16',
>>     'val': 'uint8' }}
>>  
>> -##
>> -# @X86CPURegister32:
>> -#
>> -# A X86 32-bit register
>> -#
>> -# Since: 1.5
>> -##
>> -{ 'enum': 'X86CPURegister32',
>> -  'data': [ 'EAX', 'EBX', 'ECX', 'EDX', 'ESP', 'EBP', 'ESI', 'EDI' ] }
>> -
>> -##
>> -# @X86CPUFeatureWordInfo:
>> -#
>> -# Information about a X86 CPU feature word
>> -#
>> -# @cpuid-input-eax: Input EAX value for CPUID instruction for that feature word
>> -#
>> -# @cpuid-input-ecx: Input ECX value for CPUID instruction for that
>> -#                   feature word
>> -#
>> -# @cpuid-register: Output register containing the feature bits
>> -#
>> -# @features: value of output register, containing the feature bits
>> -#
>> -# Since: 1.5
>> -##
>> -{ 'struct': 'X86CPUFeatureWordInfo',
>> -  'data': { 'cpuid-input-eax': 'int',
>> -            '*cpuid-input-ecx': 'int',
>> -            'cpuid-register': 'X86CPURegister32',
>> -            'features': 'int' } }
>> -
>> -##
>> -# @DummyForceArrays:
>> -#
>> -# Not used by QMP; hack to let us use X86CPUFeatureWordInfoList internally
>> -#
>> -# Since: 2.5
>> -##
>> -{ 'struct': 'DummyForceArrays',
>> -  'data': { 'unused': ['X86CPUFeatureWordInfo'] } }
>> -
>>  ##
>>  # @NumaCpuOptions:
>>  #
>> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
>> index 7a4a8e3847..832498c723 100644
>> --- a/target/i386/cpu.c
>> +++ b/target/i386/cpu.c
>> @@ -37,7 +37,7 @@
>>  #include "qemu/option.h"
>>  #include "qemu/config-file.h"
>>  #include "qapi/error.h"
>> -#include "qapi/qapi-visit-machine.h"
>> +#include "qapi/qapi-visit-machine-target.h"
>>  #include "qapi/qapi-visit-run-state.h"
>>  #include "qapi/qmp/qdict.h"
>>  #include "qapi/qmp/qerror.h"
>> diff --git a/target/i386/machine-stub.c b/target/i386/machine-stub.c
>> new file mode 100644
>> index 0000000000..cb301af057
>> --- /dev/null
>> +++ b/target/i386/machine-stub.c
>> @@ -0,0 +1,22 @@
>> +/*
>> + * QAPI x86 CPU features stub
>> + *
>> + * Copyright (c) 2020 Red Hat, Inc.
>> + *
>> + * Author:
>> + *   Philippe Mathieu-Daudé <philmd@redhat.com>
>> + *
>> + * This work is licensed under the terms of the GNU GPL, version 2 or later.
>> + * See the COPYING file in the top-level directory.
>> + * SPDX-License-Identifier: GPL-2.0-or-later
>> + */
>> +
>> +#include "qemu/osdep.h"
>> +#include "qapi/error.h"
>> +#include "qapi/qapi-visit-machine-target.h"
>> +
>> +void visit_type_X86CPUFeatureWordInfoList(Visitor *v, const char *name,
>> +                                      X86CPUFeatureWordInfoList **obj,
>> +                                      Error **errp)
> 
> Unusual indentation.
> 
>> +{
>> +}
> 
> Two kinds of stubs: stubs that can get called, and stubs that exist only
> to satisfy the linker.  Which kind is this one?

I suppose "stubs that exist only to satisfy the linker" must abort if
ever called...

> 
>> diff --git a/target/i386/Makefile.objs b/target/i386/Makefile.objs
>> index 48e0c28434..1cdfc9f50c 100644
>> --- a/target/i386/Makefile.objs
>> +++ b/target/i386/Makefile.objs
>> @@ -17,6 +17,7 @@ obj-$(CONFIG_HAX) += hax-all.o hax-mem.o hax-posix.o
>>  endif
>>  obj-$(CONFIG_HVF) += hvf/
>>  obj-$(CONFIG_WHPX) += whpx-all.o
>> -endif
>> +endif # CONFIG_SOFTMMU
>>  obj-$(CONFIG_SEV) += sev.o
>>  obj-$(call lnot,$(CONFIG_SEV)) += sev-stub.o
>> +obj-$(call lnot,$(CONFIG_SOFTMMU)) += machine-stub.o
> 
> Suggest
> 
>    ifeq ($(CONFIG_SOFTMMU),y)
>    ...
>    else
>    obj-y += machine-stub.o
>    endif
> 
> Matter of taste.
> 

OK