selftests: KVM: Call ucall_init when setting up in rseq_test

While x86 does not require any additional setup to use the ucall
infrastructure, arm64 needs to set up the MMIO address used to signal a
ucall to userspace. rseq_test does not initialize the MMIO address,
resulting in the test spinning indefinitely.

Fix the issue by calling ucall_init() during setup.

Fixes: 61e52f1630f5 ("KVM: selftests: Add a test for KVM_RUN+rseq to detect task migration bugs")
Signed-off-by: Oliver Upton <oupton@google.com>
Message-Id: <20210923220033.4172362-1-oupton@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/tools/testing/selftests/kvm/rseq_test.c b/tools/testing/selftests/kvm/rseq_test.c
index 060538bd405a98af2ebed09e01622308af1afe2b..c5e0dd664a7b35e4387241012e16f13e960c8f5c 100644 (file)
--- a/tools/testing/selftests/kvm/rseq_test.c
+++ b/tools/testing/selftests/kvm/rseq_test.c
@@ -180,6 +180,7 @@ int main(int argc, char *argv[])
         * CPU affinity.
         */
        vm = vm_create_default(VCPU_ID, 0, guest_code);
+       ucall_init(vm, NULL);
 
        pthread_create(&migration_thread, NULL, migration_worker, 0);