ef16b2dff4
Add a new ucall hook, GUEST_UCALL_NONE(), to allow tests to make ucalls without allocating a ucall struct, and use it to enable single-step in ARM's debug-exceptions test. Like the disable single-step path, the enabling path also needs to ensure that no exclusive access sequences are attempted after enabling single-step, as the exclusive monitor is cleared on ERET from the debug exception taken to EL2. The test currently "works" because clear_bit() isn't actually an atomic operation... yet. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20221119013450.2643007-4-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>