[PATCH v2] KVM: selftest: Add a common check to identify AMD cpu in perf event filter test

[Manali Shukla <manali.shukla@amd.com>]

PMU event filter test fails on zen4 architecture because of the
unavailability of family and model check for zen4 in use_amd_pmu().
use_amd_pmu() is added to detect architectures that supports event
select 0xc2 umask 0 as "retired branch instructions".

Model ranges in is_zen1(), is_zen2() and is_zen3() are used only for
sever SOCs, so they might not cover all the model ranges which supports
retired branch instructions.

X86_FEATURE_ZEN is a synthetic feature flag specifically added to
recognize all Zen generations by commit 232afb557835d ("x86/CPU/AMD: Add
X86_FEATURE_ZEN1"). init_amd_zen_common() uses family >= 0x17 check to
enable X86_FEATURE_ZEN.

Family 17h+ is where Zen and its successors start and that event 0xc2,0
is supported on all currently released F17h+ processors as branch
instruction retired and it is true going forward to maintain the
backward compatibility for the branch instruction retired.

Since X86_FEATURE_ZEN is not recognized in selftest framework, instead
of checking family and model value for all zen architecture, "family >=
0x17" check is added in use_amd_pmu().

Fixes: bef9a701f3eb ("selftests: kvm/x86: Add test for KVM_SET_PMU_EVENT_FILTER")
Suggested-by: Sandipan Das <sandipan.das@amd.com>
Signed-off-by: Manali Shukla <manali.shukla@amd.com>
---
 .../kvm/x86_64/pmu_event_filter_test.c        | 32 +++----------------
 1 file changed, 5 insertions(+), 27 deletions(-)

diff --git a/tools/testing/selftests/kvm/x86_64/pmu_event_filter_test.c b/tools/testing/selftests/kvm/x86_64/pmu_event_filter_test.c
index 26b3e7efe5dd..f65033fab0c0 100644
--- a/tools/testing/selftests/kvm/x86_64/pmu_event_filter_test.c
+++ b/tools/testing/selftests/kvm/x86_64/pmu_event_filter_test.c
@@ -353,38 +353,16 @@ static bool use_intel_pmu(void)
 	       kvm_pmu_has(X86_PMU_FEATURE_BRANCH_INSNS_RETIRED);
 }
 
-static bool is_zen1(uint32_t family, uint32_t model)
-{
-	return family == 0x17 && model <= 0x0f;
-}
-
-static bool is_zen2(uint32_t family, uint32_t model)
-{
-	return family == 0x17 && model >= 0x30 && model <= 0x3f;
-}
-
-static bool is_zen3(uint32_t family, uint32_t model)
-{
-	return family == 0x19 && model <= 0x0f;
-}
-
 /*
- * Determining AMD support for a PMU event requires consulting the AMD
- * PPR for the CPU or reference material derived therefrom. The AMD
- * test code herein has been verified to work on Zen1, Zen2, and Zen3.
- *
- * Feel free to add more AMD CPUs that are documented to support event
- * select 0xc2 umask 0 as "retired branch instructions."
+ * Family 17h+ is where Zen and its successors start and that event
+ * 0xc2,0 is supported on all currently released F17h+ processors as
+ * branch instruction retired and it is true going forward to maintain
+ * the backward compatibility for the branch instruction retired.
  */
 static bool use_amd_pmu(void)
 {
 	uint32_t family = kvm_cpu_family();
-	uint32_t model = kvm_cpu_model();
-
-	return host_cpu_is_amd &&
-		(is_zen1(family, model) ||
-		 is_zen2(family, model) ||
-		 is_zen3(family, model));
+	return family >= 0x17;
 }
 
 /*
-- 
2.34.1