On an aarch64 only system the 32 bit ID registers have UNDEFINED values.
As a result set_id_regs skips tests for setting fields in these registers
when testing an aarch64 only guest. This has the side effect of meaning
that we don't record an expected value for these registers, meaning that
when the subsequent tests for values being visible in guests and preserved
over reset check the value they can spuriously fail. This can be seen by
running on an emulated system with both NV and 32 bit enabled, NV will
result in the guests created by the test program being 64 bit only but
the 32 bit ID registers will have values.

Also skip those tests that use the values set in the field setting tests
for aarch64 only guests in order to avoid these spurious failures.

Signed-off-by: Mark Brown <broonie@kernel.org>
---
 tools/testing/selftests/kvm/arm64/set_id_regs.c | 49 ++++++++++++++++++-------
 1 file changed, 36 insertions(+), 13 deletions(-)

diff --git a/tools/testing/selftests/kvm/arm64/set_id_regs.c b/tools/testing/selftests/kvm/arm64/set_id_regs.c
index 5837da63e9b9..908b3c8947d9 100644
--- a/tools/testing/selftests/kvm/arm64/set_id_regs.c
+++ b/tools/testing/selftests/kvm/arm64/set_id_regs.c

@@ -295,6 +295,13 @@ static const char *get_reg_name(u64 id)
 	}
 }
 
+static inline bool is_aarch32_id_reg(u64 id)
+{
+	return (sys_reg_Op0(id) == 3 && sys_reg_Op1(id) == 0 &&
+		sys_reg_CRn(id) == 0 && sys_reg_CRm(id) >= 1 &&
+		sys_reg_CRm(id) <= 3);
+}
+