On 12.07.22 11:52, Ilya Leoshkevich wrote: > On Tue, 2022-07-12 at 10:42 +0530, Richard Henderson wrote: >> On 7/12/22 00:26, Ilya Leoshkevich wrote: >>> System tests on x86 use isa-debug-exit device in order to signal >>> success or failure to the test runner. Unfortunately it's not >>> easily >>> usable on other architectures, since a guest needs to access >>> address_space_io, which may not be as straightforward as on x86. >>> Also, it requires adding ISA bus, which an architecture might not >>> otherwise need. >>> >>> Introduce mmio-debug-exit device, which has the same semantics, but >>> is >>> triggered by writes to memory. >>> >>> Signed-off-by: Ilya Leoshkevich <i...@linux.ibm.com> >> >> You shouldn't need this for s390x, as there are already (at least) >> two other paths to >> qemu_system_shutdown_request. >> >> E.g. SIGP, which has a stop option. >> >> >> r~ >> > > I would normally use lpswe + disabled wait, but this always gives me > exit status code 0, which doesn't allow easily distinguishing between > success and failure. > > Code-wise SIGP seems to do roughly the same thing, and a quick > experiment with: > > lgfi %r4,-1 > lgfi %r5,-1 > larl %r6,_cpuaddr > stap 0(%r6) > lh %r6,0(%r6) > nilh %r6,0 > sigp %r4,%r6,5 > _cpuaddr: .short 0 > > confirmed that we get exit status code 0 as well.
disabled wait should trigger a qemu_system_guest_panicked(). But "panic_action == PANIC_ACTION_SHUTDOWN" seems to only make qemu_main_loop() return with main_loop_should_exit() == true. main/qemu_main will always return 0. We could return != 0 on guest panic, but not sure if that could break existing scripts. We'd need a new QEMU toggle for that most probably ... -- Thanks, David / dhildenb
