Hi Shuah,
Thank you very much for looking into this.
On 9/5/24 11:02 AM, Shuah Khan wrote:
When resctrl is built on architectures without __cpuid_count()
support, build fails. resctrl uses __cpuid_count() defined in
kselftest.h.
Even though the problem is seen while building resctrl on aarch64,
this error can be seen on any platform that doesn't support CPUID.
CPUID is a x86/x86-64 feature and code paths with CPUID asm commands
will fail to build on all other architectures.
All others tests call __cpuid_count() do so from x86/x86_64 code paths
when _i386__ or __x86_64__ are defined. resctrl is an exception.
Fix the problem by defining __cpuid_count() only when __i386__ or
__x86_64__ are defined in kselftest.h and changing resctrl to call
__cpuid_count() only when __i386__ or __x86_64__ are defined.
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:326:6:
../kselftest.h:74:9: error: impossible constraint in ‘asm’
74 | __asm__ __volatile__ ("cpuid\n\t" \
| ^~~~~~~
cat_test.c:304:17: note: in expansion of macro ‘__cpuid_count’
304 | __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:306:17: note: in expansion of macro ‘__cpuid_count’
306 | __cpuid_count(0x10, 2, eax, ebx, ecx, edx);
If needing to know where this fix is needed, there can be a:
Fixes: ae638551ab64 ("selftests/resctrl: Add non-contiguous CBMs CAT test")
Reported-by: Muhammad Usama Anjum <usama.anjum@xxxxxxxxxxxxx>
Perhaps:
Closes: https://lore.kernel.org/lkml/20240809071059.265914-1-usama.anjum@xxxxxxxxxxxxx/
Reported-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
Signed-off-by: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>
---
tools/testing/selftests/kselftest.h | 2 ++
tools/testing/selftests/resctrl/cat_test.c | 6 ++++--
2 files changed, 6 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/kselftest.h b/tools/testing/selftests/kselftest.h
index b8967b6e29d5..e195ec156859 100644
--- a/tools/testing/selftests/kselftest.h
+++ b/tools/testing/selftests/kselftest.h
@@ -61,6 +61,7 @@
#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
#endif
+#if defined(__i386__) || defined(__x86_64__) /* arch */
/*
* gcc cpuid.h provides __cpuid_count() since v4.4.
* Clang/LLVM cpuid.h provides __cpuid_count() since v3.4.0.
@@ -75,6 +76,7 @@
: "=a" (a), "=b" (b), "=c" (c), "=d" (d) \
: "0" (level), "2" (count))
#endif
+#endif /* end arch */
/* define kselftest exit codes */
#define KSFT_PASS 0
diff --git a/tools/testing/selftests/resctrl/cat_test.c b/tools/testing/selftests/resctrl/cat_test.c
index 742782438ca3..ae3f0fa5390b 100644
--- a/tools/testing/selftests/resctrl/cat_test.c
+++ b/tools/testing/selftests/resctrl/cat_test.c
@@ -290,12 +290,12 @@ 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;
-
/* AMD always supports non-contiguous CBM. */
if (get_vendor() == ARCH_AMD)
return true;
+#if defined(__i386__) || defined(__x86_64__) /* arch */
+ unsigned int eax, ebx, ecx, edx;
/* Intel support for non-contiguous CBM needs to be discovered. */
if (!strcmp(test->resource, "L3"))
__cpuid_count(0x10, 1, eax, ebx, ecx, edx);
@@ -305,6 +305,8 @@ static bool arch_supports_noncont_cat(const struct resctrl_test *test)
return false;
return ((ecx >> 3) & 1);
+#endif /* end arch */
+ return false;
}
static int noncont_cat_run_test(const struct resctrl_test *test,
Thank you very much.
Acked-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
Reinette
