1. Patchew
  2. QEMU
  3. [PATCH v3 00/11] user-mode: Prune build dependencies (part 3)
  4. View patch

[PATCH v3 10/11] target/i386: Restrict X86CPUFeatureWord to X86 targets

Philippe Mathieu-Daudé posted 11 patches 5 years, 4 months ago
There is a newer version of this series
[PATCH v3 10/11] target/i386: Restrict X86CPUFeatureWord to X86 targets
Posted by Philippe Mathieu-Daudé 5 years, 4 months ago 
Only qemu-system-FOO and qemu-storage-daemon provide QMP
monitors, therefore such declarations and definitions are
irrelevant for user-mode emulation.

Restricting the x86-specific commands to machine-target.json
pulls less QAPI-generated code into user-mode.

Add a stub to satisfy linking in user-mode:

  /usr/bin/ld: libqemu-i386-linux-user.fa.p/target_i386_cpu.c.o: in function `x86_cpu_get_feature_words':
  target/i386/cpu.c:4643: undefined reference to `visit_type_X86CPUFeatureWordInfoList'
  collect2: error: ld returned 1 exit status
  make: *** [Makefile.ninja:1125: qemu-i386] Error 1

Acked-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
v3: Reworded + Meson rebase
---
 qapi/machine-target.json   | 45 ++++++++++++++++++++++++++++++++++++++
 qapi/machine.json          | 42 -----------------------------------
 target/i386/cpu.c          |  2 +-
 target/i386/feature-stub.c | 23 +++++++++++++++++++
 target/i386/meson.build    |  1 +
 5 files changed, 70 insertions(+), 43 deletions(-)
 create mode 100644 target/i386/feature-stub.c

diff --git a/qapi/machine-target.json b/qapi/machine-target.json
index 698850cc78..b4d769a53b 100644
--- a/qapi/machine-target.json
+++ b/qapi/machine-target.json
@@ -4,6 +4,51 @@
 # 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 72f014bb5b..cb878acdac 100644
--- a/qapi/machine.json
+++ b/qapi/machine.json
@@ -544,48 +544,6 @@
    '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 3ffd877dd5..d45fa217cc 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -38,7 +38,7 @@
 #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/feature-stub.c b/target/i386/feature-stub.c
new file mode 100644
index 0000000000..787c3c7fa1
--- /dev/null
+++ b/target/i386/feature-stub.c
@@ -0,0 +1,23 @@
+/*
+ * 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"
+
+bool visit_type_X86CPUFeatureWordInfoList(Visitor *v, const char *name,
+                                          X86CPUFeatureWordInfoList **obj,
+                                          Error **errp)
+{
+    g_assert_not_reached();
+}
diff --git a/target/i386/meson.build b/target/i386/meson.build
index e0b71ade56..0c5d9e6caf 100644
--- a/target/i386/meson.build
+++ b/target/i386/meson.build
@@ -5,6 +5,7 @@ i386_ss.add(files(
   'helper.c',
   'xsave_helper.c',
 ))
+i386_ss.add(when: 'CONFIG_SOFTMMU', if_false: files('feature-stub.c'))
 i386_ss.add(when: 'CONFIG_TCG', if_true: files(
   'bpt_helper.c',
   'cc_helper.c',
-- 
2.26.2
Re: [PATCH v3 10/11] target/i386: Restrict X86CPUFeatureWord to X86 targets
Posted by Eduardo Habkost 5 years, 4 months ago 
On Wed, Sep 30, 2020 at 06:49:48PM +0200, Philippe Mathieu-Daudé wrote:
> Only qemu-system-FOO and qemu-storage-daemon provide QMP
> monitors, therefore such declarations and definitions are
> irrelevant for user-mode emulation.
> 
> Restricting the x86-specific commands to machine-target.json
> pulls less QAPI-generated code into user-mode.
> 
> Add a stub to satisfy linking in user-mode:
> 
>   /usr/bin/ld: libqemu-i386-linux-user.fa.p/target_i386_cpu.c.o: in function `x86_cpu_get_feature_words':
>   target/i386/cpu.c:4643: undefined reference to `visit_type_X86CPUFeatureWordInfoList'
>   collect2: error: ld returned 1 exit status
>   make: *** [Makefile.ninja:1125: qemu-i386] Error 1
> 

If you don't want the QAPI definitions in user mode, there's no
reason to register the properties in user mode.  Wrapping #ifdef
around "feature-words" and "filtered-features" registration would
be simpler than adding a stub.

> Acked-by: Richard Henderson <richard.henderson@linaro.org>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
> v3: Reworded + Meson rebase
> ---
>  qapi/machine-target.json   | 45 ++++++++++++++++++++++++++++++++++++++
>  qapi/machine.json          | 42 -----------------------------------
>  target/i386/cpu.c          |  2 +-
>  target/i386/feature-stub.c | 23 +++++++++++++++++++
>  target/i386/meson.build    |  1 +
>  5 files changed, 70 insertions(+), 43 deletions(-)
>  create mode 100644 target/i386/feature-stub.c
> 
> diff --git a/qapi/machine-target.json b/qapi/machine-target.json
> index 698850cc78..b4d769a53b 100644
> --- a/qapi/machine-target.json
> +++ b/qapi/machine-target.json
> @@ -4,6 +4,51 @@
>  # 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 72f014bb5b..cb878acdac 100644
> --- a/qapi/machine.json
> +++ b/qapi/machine.json
> @@ -544,48 +544,6 @@
>     '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 3ffd877dd5..d45fa217cc 100644
> --- a/target/i386/cpu.c
> +++ b/target/i386/cpu.c
> @@ -38,7 +38,7 @@
>  #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/feature-stub.c b/target/i386/feature-stub.c
> new file mode 100644
> index 0000000000..787c3c7fa1
> --- /dev/null
> +++ b/target/i386/feature-stub.c
> @@ -0,0 +1,23 @@
> +/*
> + * 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"
> +
> +bool visit_type_X86CPUFeatureWordInfoList(Visitor *v, const char *name,
> +                                          X86CPUFeatureWordInfoList **obj,
> +                                          Error **errp)
> +{
> +    g_assert_not_reached();
> +}
> diff --git a/target/i386/meson.build b/target/i386/meson.build
> index e0b71ade56..0c5d9e6caf 100644
> --- a/target/i386/meson.build
> +++ b/target/i386/meson.build
> @@ -5,6 +5,7 @@ i386_ss.add(files(
>    'helper.c',
>    'xsave_helper.c',
>  ))
> +i386_ss.add(when: 'CONFIG_SOFTMMU', if_false: files('feature-stub.c'))
>  i386_ss.add(when: 'CONFIG_TCG', if_true: files(
>    'bpt_helper.c',
>    'cc_helper.c',
> -- 
> 2.26.2
> 
> 

-- 
Eduardo

Patchew 2.1-devel-b67e4c2

© 2016 - 2026 Red Hat, Inc.