selftests: kvm/s390x: use vm_create_barebones()

This function does the same but makes it clearer why one would use
the "____"-prefixed version of vm_create().

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

KVM: selftests: Rename the ASSERT_EQ macro

There is already an ASSERT_EQ macro in the file
tools/testing/selftests/kselftest_harness.h, so currently KVM selftests
can't include test_util.h from the KVM selftests together with that file.
Rename the macro in the KVM selftests to TEST_ASSERT_EQ to avoid the
problem - it is also more similar to the other macros in test_util.h that
way.

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Link: https://lore.kernel.org/r/20230712075910.22480-2-thuth@redhat.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

KVM: s390: selftests: add selftest for CMMA migration

Add a selftest for CMMA migration on s390.

The tests cover:
- interaction of dirty tracking and migration mode, see my recent patch
"KVM: s390: disable migration mode when dirty tracking is disabled" [1],
- several invalid calls of KVM_S390_GET_CMMA_BITS, for example: invalid
flags, CMMA support off, with/without peeking
- ensure KVM_S390_GET_CMMA_BITS initally reports all pages as dirty,
- ensure KVM_S390_GET_CMMA_BITS properly skips over holes in memslots, but
also non-dirty pages

Note that without the patch at [1] and the small fix in this series, the
selftests will fail.

[1] https://lore.kernel.org/all/20230127140532.230651-2-nrb@linux.ibm.com/

Signed-off-by: Nico Boehr <nrb@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Message-Id: <20230324145424.293889-3-nrb@linux.ibm.com>
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
[frankja@linux.ibm.com: squashed
20230606150510.671301-1-nrb@linux.ibm.com / "KVM: s390: selftests:
CMMA: don't run if CMMA not supported"]
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>