* [PATCH v3 1/3] selftests/resctrl: Generalize non-contiguous CAT check
2024-08-29 13:16 [PATCH v3 0/3] selftests: Fix cpuid / vendor checking build issues Ilpo Järvinen
@ 2024-08-29 13:16 ` Ilpo Järvinen
2024-08-29 13:16 ` [PATCH v3 2/3] selftests/resctrl: Always initialize ecx to avoid build warnings Ilpo Järvinen
2024-08-29 13:16 ` [PATCH v3 3/3] kselftest: Provide __cpuid_count() stub on non-x86 archs Ilpo Järvinen
2 siblings, 0 replies; 6+ messages in thread
From: Ilpo Järvinen @ 2024-08-29 13:16 UTC (permalink / raw)
To: Muhammad Usama Anjum, Shuah Khan, Reinette Chatre,
linux-kselftest
Cc: linux-kernel, Shaopeng Tan, Fenghua Yu,
Maciej Wieczór-Retman, Ilpo Järvinen
arch_supports_noncont_cat() checks if vendor is ARCH_AMD and if that is
not true, ARCH_INTEL is assumed which might not be true either because
get_vendor() can also return zero if neither AMD nor Intel is detected.
Generalize the vendor check using switch/case logic and return false
for unknown vendors.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
---
tools/testing/selftests/resctrl/cat_test.c | 26 +++++++++++++---------
1 file changed, 16 insertions(+), 10 deletions(-)
diff --git a/tools/testing/selftests/resctrl/cat_test.c b/tools/testing/selftests/resctrl/cat_test.c
index 742782438ca3..51a1cb6aac34 100644
--- a/tools/testing/selftests/resctrl/cat_test.c
+++ b/tools/testing/selftests/resctrl/cat_test.c
@@ -292,19 +292,25 @@ static bool arch_supports_noncont_cat(const struct resctrl_test *test)
{
unsigned int eax, ebx, ecx, edx;
- /* AMD always supports non-contiguous CBM. */
- if (get_vendor() == ARCH_AMD)
+ switch (get_vendor()) {
+ case ARCH_AMD:
+ /* AMD always supports non-contiguous CBM. */
return true;
- /* Intel support for non-contiguous CBM needs to be discovered. */
- if (!strcmp(test->resource, "L3"))
- __cpuid_count(0x10, 1, eax, ebx, ecx, edx);
- else if (!strcmp(test->resource, "L2"))
- __cpuid_count(0x10, 2, eax, ebx, ecx, edx);
- else
- return false;
+ case ARCH_INTEL:
+ /* Intel support for non-contiguous CBM needs to be discovered. */
+ if (!strcmp(test->resource, "L3"))
+ __cpuid_count(0x10, 1, eax, ebx, ecx, edx);
+ else if (!strcmp(test->resource, "L2"))
+ __cpuid_count(0x10, 2, eax, ebx, ecx, edx);
+ else
+ return false;
+
+ return ((ecx >> 3) & 1);
- return ((ecx >> 3) & 1);
+ default:
+ return false;
+ }
}
static int noncont_cat_run_test(const struct resctrl_test *test,
--
2.39.2
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH v3 2/3] selftests/resctrl: Always initialize ecx to avoid build warnings
2024-08-29 13:16 [PATCH v3 0/3] selftests: Fix cpuid / vendor checking build issues Ilpo Järvinen
2024-08-29 13:16 ` [PATCH v3 1/3] selftests/resctrl: Generalize non-contiguous CAT check Ilpo Järvinen
@ 2024-08-29 13:16 ` Ilpo Järvinen
2024-08-29 13:16 ` [PATCH v3 3/3] kselftest: Provide __cpuid_count() stub on non-x86 archs Ilpo Järvinen
2 siblings, 0 replies; 6+ messages in thread
From: Ilpo Järvinen @ 2024-08-29 13:16 UTC (permalink / raw)
To: Muhammad Usama Anjum, Shuah Khan, Reinette Chatre,
linux-kselftest
Cc: linux-kernel, Shaopeng Tan, Fenghua Yu,
Maciej Wieczór-Retman, Ilpo Järvinen
To avoid warnings when __cpuid_count() is an empty stub, always
initialize ecx because it is used in the return statement.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
---
tools/testing/selftests/resctrl/cat_test.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/resctrl/cat_test.c b/tools/testing/selftests/resctrl/cat_test.c
index 51a1cb6aac34..9882c5d19408 100644
--- a/tools/testing/selftests/resctrl/cat_test.c
+++ b/tools/testing/selftests/resctrl/cat_test.c
@@ -290,7 +290,7 @@ static int cat_run_test(const struct resctrl_test *test, const struct user_param
static bool arch_supports_noncont_cat(const struct resctrl_test *test)
{
- unsigned int eax, ebx, ecx, edx;
+ unsigned int eax, ebx, ecx = 0, edx;
switch (get_vendor()) {
case ARCH_AMD:
--
2.39.2
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH v3 3/3] kselftest: Provide __cpuid_count() stub on non-x86 archs
2024-08-29 13:16 [PATCH v3 0/3] selftests: Fix cpuid / vendor checking build issues Ilpo Järvinen
2024-08-29 13:16 ` [PATCH v3 1/3] selftests/resctrl: Generalize non-contiguous CAT check Ilpo Järvinen
2024-08-29 13:16 ` [PATCH v3 2/3] selftests/resctrl: Always initialize ecx to avoid build warnings Ilpo Järvinen
@ 2024-08-29 13:16 ` Ilpo Järvinen
2024-09-01 5:06 ` kernel test robot
2024-09-03 9:57 ` Ilpo Järvinen
2 siblings, 2 replies; 6+ messages in thread
From: Ilpo Järvinen @ 2024-08-29 13:16 UTC (permalink / raw)
To: Muhammad Usama Anjum, Shuah Khan, Reinette Chatre,
linux-kselftest
Cc: linux-kernel, Shaopeng Tan, Fenghua Yu,
Maciej Wieczór-Retman, Ilpo Järvinen
Building resctrl selftest fails on ARM because it uses __cpuid_count()
that fails the build with error:
CC resctrl_tests
In file included from resctrl.h:24,
from cat_test.c:11:
In function 'arch_supports_noncont_cat',
inlined from 'noncont_cat_run_test' at cat_test.c:323:6:
../kselftest.h:74:9: error: impossible constraint in 'asm'
74 | __asm__ __volatile__ ("cpuid\n\t" \
| ^~~~~~~
cat_test.c:301:17: note: in expansion of macro '__cpuid_count'
301 | __cpuid_count(0x10, 1, eax, ebx, ecx, edx);
| ^~~~~~~~~~~~~
../kselftest.h:74:9: error: impossible constraint in 'asm'
74 | __asm__ __volatile__ ("cpuid\n\t" \
| ^~~~~~~
cat_test.c:303:17: note: in expansion of macro '__cpuid_count'
303 | __cpuid_count(0x10, 2, eax, ebx, ecx, edx);
| ^~~~~~~~~~~~~
The resctrl selftest would run that code only on Intel CPUs but as is,
the code cannot be build at all.
Define HAVE_CPUID in lib.mk based on ARCH (x86 or x86_64). If ARCH is
not set, acquire it using uname -m.
Provide a stub for __cpuid_count() if HAVE_CPUID is not present to
allow build to succeed. The stub casts its arguments to void to avoid
causing "unused variable" or "set but not used" warnings.
Fixes: ae638551ab64 ("selftests/resctrl: Add non-contiguous CBMs CAT test")
Reported-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
---
v3:
- Remove "empty" wording
- Also cast input parameters to void
- Initialize ARCH from uname -m if not set (this might allow cleaning
up some other makefiles but that is left as future work)
v2:
- Removed RFC & added Fixes and Tested-by
- Fixed the error message's line splits
- Noted down the reason for void casts in the stub
---
tools/testing/selftests/kselftest.h | 6 ++++++
tools/testing/selftests/lib.mk | 6 ++++++
2 files changed, 12 insertions(+)
diff --git a/tools/testing/selftests/kselftest.h b/tools/testing/selftests/kselftest.h
index b8967b6e29d5..9c4bfbf107f1 100644
--- a/tools/testing/selftests/kselftest.h
+++ b/tools/testing/selftests/kselftest.h
@@ -70,10 +70,16 @@
* have __cpuid_count().
*/
#ifndef __cpuid_count
+#ifdef HAVE_CPUID
#define __cpuid_count(level, count, a, b, c, d) \
__asm__ __volatile__ ("cpuid\n\t" \
: "=a" (a), "=b" (b), "=c" (c), "=d" (d) \
: "0" (level), "2" (count))
+#else
+#define __cpuid_count(level, count, a, b, c, d) do { \
+ (void)level; (void)count; (void)a; (void)b; (void)c; (void)d; \
+} while (0)
+#endif
#endif
/* define kselftest exit codes */
diff --git a/tools/testing/selftests/lib.mk b/tools/testing/selftests/lib.mk
index d6edcfcb5be8..8e3069926153 100644
--- a/tools/testing/selftests/lib.mk
+++ b/tools/testing/selftests/lib.mk
@@ -23,6 +23,8 @@ CLANG_TARGET_FLAGS_x86_64 := x86_64-linux-gnu
# Default to host architecture if ARCH is not explicitly given.
ifeq ($(ARCH),)
+ARCH := $(shell uname -m 2>/dev/null || echo not)
+ARCH := $(shell echo $(ARCH) | sed -e s/i.86/x86/)
CLANG_TARGET_FLAGS := $(shell $(CLANG) -print-target-triple)
else
CLANG_TARGET_FLAGS := $(CLANG_TARGET_FLAGS_$(ARCH))
@@ -199,6 +201,10 @@ clean: $(if $(TEST_GEN_MODS_DIR),clean_mods_dir)
# Build with _GNU_SOURCE by default
CFLAGS += -D_GNU_SOURCE=
+ifeq ($(ARCH),$(filter $(ARCH),x86 x86_64))
+CFLAGS += -DHAVE_CPUID=
+endif
+
# Enables to extend CFLAGS and LDFLAGS from command line, e.g.
# make USERCFLAGS=-Werror USERLDFLAGS=-static
CFLAGS += $(USERCFLAGS)
--
2.39.2
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH v3 3/3] kselftest: Provide __cpuid_count() stub on non-x86 archs
2024-08-29 13:16 ` [PATCH v3 3/3] kselftest: Provide __cpuid_count() stub on non-x86 archs Ilpo Järvinen
@ 2024-09-01 5:06 ` kernel test robot
2024-09-03 9:57 ` Ilpo Järvinen
1 sibling, 0 replies; 6+ messages in thread
From: kernel test robot @ 2024-09-01 5:06 UTC (permalink / raw)
To: Ilpo Järvinen; +Cc: oe-kbuild-all
Hi Ilpo,
kernel test robot noticed the following build warnings:
[auto build test WARNING on shuah-kselftest/next]
[also build test WARNING on shuah-kselftest/fixes linus/master v6.11-rc5 next-20240830]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Ilpo-J-rvinen/selftests-resctrl-Generalize-non-contiguous-CAT-check/20240829-212248
base: https://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest.git next
patch link: https://lore.kernel.org/r/20240829131657.1917-4-ilpo.jarvinen%40linux.intel.com
patch subject: [PATCH v3 3/3] kselftest: Provide __cpuid_count() stub on non-x86 archs
:::::: branch date: 3 days ago
:::::: commit date: 3 days ago
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240901/202409010931.Xl6TB9hc-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/r/202409010931.Xl6TB9hc-lkp@intel.com/
All warnings (new ones prefixed by >>):
corrupt_xstate_header.c: In function 'xsave_enabled':
>> corrupt_xstate_header.c:29:20: warning: 'ecx' is used uninitialized [-Wuninitialized]
29 | return ecx & (1U << 27);
| ~~~~^~~~~~~~~~~~
corrupt_xstate_header.c:24:32: note: 'ecx' was declared here
24 | unsigned int eax, ebx, ecx, edx;
| ^~~
--
amx.c: In function 'check_cpuid_xtiledata':
>> amx.c:123:19: warning: 'ebx' is used uninitialized [-Wuninitialized]
123 | xbuf_size = ebx;
| ~~~~~~~~~~^~~~~
amx.c:111:23: note: 'ebx' was declared here
111 | uint32_t eax, ebx, ecx, edx;
| ^~~
>> amx.c:131:13: warning: 'eax' is used uninitialized [-Wuninitialized]
131 | if (!eax || !ebx)
| ^~~~
amx.c:111:18: note: 'eax' was declared here
111 | uint32_t eax, ebx, ecx, edx;
| ^~~
--
lam.c: In function 'cpu_has_lam':
>> lam.c:124:24: warning: 'cpuinfo' is used uninitialized [-Wuninitialized]
124 | return (cpuinfo[0] & (1 << 26));
| ~~~~~~~^~~
lam.c:120:22: note: 'cpuinfo' declared here
120 | unsigned int cpuinfo[4];
| ^~~~~~~
lam.c: In function 'cpu_has_la57':
lam.c:134:24: warning: 'cpuinfo' is used uninitialized [-Wuninitialized]
134 | return (cpuinfo[2] & (1 << 16));
| ~~~~~~~^~~
lam.c:130:22: note: 'cpuinfo' declared here
130 | unsigned int cpuinfo[4];
| ^~~~~~~
vim +/ecx +29 tools/testing/selftests/x86/corrupt_xstate_header.c
b7c11876d24bdd7 Andy Lutomirski 2021-06-08 21
b7c11876d24bdd7 Andy Lutomirski 2021-06-08 22 static inline int xsave_enabled(void)
b7c11876d24bdd7 Andy Lutomirski 2021-06-08 23 {
b7c11876d24bdd7 Andy Lutomirski 2021-06-08 24 unsigned int eax, ebx, ecx, edx;
b7c11876d24bdd7 Andy Lutomirski 2021-06-08 25
170d1c23f2a3569 Reinette Chatre 2022-04-25 26 __cpuid_count(0x1, 0x0, eax, ebx, ecx, edx);
b7c11876d24bdd7 Andy Lutomirski 2021-06-08 27
b7c11876d24bdd7 Andy Lutomirski 2021-06-08 28 /* Is CR4.OSXSAVE enabled ? */
b7c11876d24bdd7 Andy Lutomirski 2021-06-08 @29 return ecx & (1U << 27);
b7c11876d24bdd7 Andy Lutomirski 2021-06-08 30 }
b7c11876d24bdd7 Andy Lutomirski 2021-06-08 31
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH v3 3/3] kselftest: Provide __cpuid_count() stub on non-x86 archs
2024-08-29 13:16 ` [PATCH v3 3/3] kselftest: Provide __cpuid_count() stub on non-x86 archs Ilpo Järvinen
2024-09-01 5:06 ` kernel test robot
@ 2024-09-03 9:57 ` Ilpo Järvinen
1 sibling, 0 replies; 6+ messages in thread
From: Ilpo Järvinen @ 2024-09-03 9:57 UTC (permalink / raw)
To: Muhammad Usama Anjum, Shuah Khan
Cc: Reinette Chatre, linux-kselftest, LKML, Shaopeng Tan, Fenghua Yu,
Maciej Wieczór-Retman
[-- Attachment #1: Type: text/plain, Size: 3936 bytes --]
On Thu, 29 Aug 2024, Ilpo Järvinen wrote:
> Building resctrl selftest fails on ARM because it uses __cpuid_count()
> that fails the build with error:
>
> CC resctrl_tests
> In file included from resctrl.h:24,
> from cat_test.c:11:
> In function 'arch_supports_noncont_cat',
> inlined from 'noncont_cat_run_test' at cat_test.c:323:6:
> ../kselftest.h:74:9: error: impossible constraint in 'asm'
> 74 | __asm__ __volatile__ ("cpuid\n\t" \
> | ^~~~~~~
> cat_test.c:301:17: note: in expansion of macro '__cpuid_count'
> 301 | __cpuid_count(0x10, 1, eax, ebx, ecx, edx);
> | ^~~~~~~~~~~~~
> ../kselftest.h:74:9: error: impossible constraint in 'asm'
> 74 | __asm__ __volatile__ ("cpuid\n\t" \
> | ^~~~~~~
> cat_test.c:303:17: note: in expansion of macro '__cpuid_count'
> 303 | __cpuid_count(0x10, 2, eax, ebx, ecx, edx);
> | ^~~~~~~~~~~~~
>
> The resctrl selftest would run that code only on Intel CPUs but as is,
> the code cannot be build at all.
>
> Define HAVE_CPUID in lib.mk based on ARCH (x86 or x86_64). If ARCH is
> not set, acquire it using uname -m.
>
> Provide a stub for __cpuid_count() if HAVE_CPUID is not present to
> allow build to succeed. The stub casts its arguments to void to avoid
> causing "unused variable" or "set but not used" warnings.
>
> Fixes: ae638551ab64 ("selftests/resctrl: Add non-contiguous CBMs CAT test")
> Reported-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
> ---
> v3:
> - Remove "empty" wording
> - Also cast input parameters to void
> - Initialize ARCH from uname -m if not set (this might allow cleaning
> up some other makefiles but that is left as future work)
> v2:
> - Removed RFC & added Fixes and Tested-by
> - Fixed the error message's line splits
> - Noted down the reason for void casts in the stub
> ---
> tools/testing/selftests/kselftest.h | 6 ++++++
> tools/testing/selftests/lib.mk | 6 ++++++
> 2 files changed, 12 insertions(+)
>
> diff --git a/tools/testing/selftests/kselftest.h b/tools/testing/selftests/kselftest.h
> index b8967b6e29d5..9c4bfbf107f1 100644
> --- a/tools/testing/selftests/kselftest.h
> +++ b/tools/testing/selftests/kselftest.h
> @@ -70,10 +70,16 @@
> * have __cpuid_count().
> */
> #ifndef __cpuid_count
> +#ifdef HAVE_CPUID
> #define __cpuid_count(level, count, a, b, c, d) \
> __asm__ __volatile__ ("cpuid\n\t" \
> : "=a" (a), "=b" (b), "=c" (c), "=d" (d) \
> : "0" (level), "2" (count))
> +#else
> +#define __cpuid_count(level, count, a, b, c, d) do { \
> + (void)level; (void)count; (void)a; (void)b; (void)c; (void)d; \
> +} while (0)
> +#endif
> #endif
>
> /* define kselftest exit codes */
> diff --git a/tools/testing/selftests/lib.mk b/tools/testing/selftests/lib.mk
> index d6edcfcb5be8..8e3069926153 100644
> --- a/tools/testing/selftests/lib.mk
> +++ b/tools/testing/selftests/lib.mk
> @@ -23,6 +23,8 @@ CLANG_TARGET_FLAGS_x86_64 := x86_64-linux-gnu
>
> # Default to host architecture if ARCH is not explicitly given.
> ifeq ($(ARCH),)
> +ARCH := $(shell uname -m 2>/dev/null || echo not)
> +ARCH := $(shell echo $(ARCH) | sed -e s/i.86/x86/)
> CLANG_TARGET_FLAGS := $(shell $(CLANG) -print-target-triple)
> else
> CLANG_TARGET_FLAGS := $(CLANG_TARGET_FLAGS_$(ARCH))
> @@ -199,6 +201,10 @@ clean: $(if $(TEST_GEN_MODS_DIR),clean_mods_dir)
> # Build with _GNU_SOURCE by default
> CFLAGS += -D_GNU_SOURCE=
>
> +ifeq ($(ARCH),$(filter $(ARCH),x86 x86_64))
> +CFLAGS += -DHAVE_CPUID=
> +endif
Hpmf, scratch this. CFLAGS are overwritten by x86 selftest makefile so I
need to reorder things there before making this change.
--
i.
^ permalink raw reply [flat|nested] 6+ messages in thread