On 4/1/22 4:10 PM, Chang S. Bae wrote:
When a CPU does not have AMX, the test fails. But this is wrong as it
should be runnable regardless. Skip the test instead.
Reported-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Fixes: 6a3e0651b4a ("selftests/x86/amx: Add test cases for AMX state management")
Signed-off-by: Chang S. Bae <chang.seok.bae@xxxxxxxxx>
Cc: linux-kselftest@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
tools/testing/selftests/x86/amx.c | 42 +++++++++++++++++++++++--------
1 file changed, 31 insertions(+), 11 deletions(-)
diff --git a/tools/testing/selftests/x86/amx.c b/tools/testing/selftests/x86/amx.c
index 3615ef4a48bb..14abb6072a7d 100644
--- a/tools/testing/selftests/x86/amx.c
+++ b/tools/testing/selftests/x86/amx.c
@@ -106,6 +106,12 @@ static void clearhandler(int sig)
#define CPUID_LEAF1_ECX_XSAVE_MASK (1 << 26)
#define CPUID_LEAF1_ECX_OSXSAVE_MASK (1 << 27)
+
+static struct {
+ unsigned xsave: 1;
+ unsigned osxsave: 1;
+} cpuinfo;
+
Why is this needed? Also naming this cpuinfo is confuing.
static inline void check_cpuid_xsave(void)
{
uint32_t eax, ebx, ecx, edx;
@@ -118,10 +124,8 @@ static inline void check_cpuid_xsave(void)
eax = 1;
ecx = 0;
cpuid(&eax, &ebx, &ecx, &edx);
- if (!(ecx & CPUID_LEAF1_ECX_XSAVE_MASK))
- fatal_error("cpuid: no CPU xsave support");
- if (!(ecx & CPUID_LEAF1_ECX_OSXSAVE_MASK))
- fatal_error("cpuid: no OS xsave support");
+ cpuinfo.xsave = !!(ecx & CPUID_LEAF1_ECX_XSAVE_MASK);
+ cpuinfo.osxsave = !!(ecx & CPUID_LEAF1_ECX_OSXSAVE_MASK);
Why add this complexity. Why not just Skip here?
}
static uint32_t xbuf_size;
@@ -161,14 +165,31 @@ static void check_cpuid_xtiledata(void)
* eax: XTILEDATA state component size
* ebx: XTILEDATA state component offset in user buffer
*/
- if (!eax || !ebx)
- fatal_error("xstate cpuid: invalid tile data size/offset: %d/%d",
- eax, ebx);
-
xtiledata.size = eax;
xtiledata.xbuf_offset = ebx;
}
+static bool amx_available(void)
+{
+ check_cpuid_xsave();
+ if (!cpuinfo.xsave) {
+ printf("[SKIP]\tcpuid: no CPU xsave support\n");
+ return false;
+ } else if (!cpuinfo.osxsave) {
+ printf("[SKIP]\tcpuid: no OS xsave support\n");
+ return false;
+ }
+
+ check_cpuid_xtiledata();
+ if (!xtiledata.size || !xtiledata.xbuf_offset) {
+ printf("[SKIP]\txstate cpuid: no tile data (size/offset: %d/%d)\n",
+ xtiledata.size, xtiledata.xbuf_offset);
+ return false;
+ }
+
+ return true;
+}
+
I am not seeing any value in adding this layer of abstraction.
Keep it simple and do the handling in main()
/* The helpers for managing XSAVE buffer and tile states: */
struct xsave_buffer *alloc_xbuf(void)
@@ -826,9 +847,8 @@ static void test_context_switch(void)
int main(void)
{
- /* Check hardware availability at first */
- check_cpuid_xsave();
- check_cpuid_xtiledata();
+ if (!amx_available())
+ return 0;
This should KSFT_SKIP for this to be reported as a skip. Returning 0
will be reported as a Pass.
init_stashed_xsave();
sethandler(SIGILL, handle_noperm, 0);
thanks,
-- Shuah
