Peter Maydell <[email protected]> writes: > On Mon, 13 Jul 2026 at 15:49, Fabiano Rosas <[email protected]> wrote: >> >> Peter Maydell <[email protected]> writes: >> > - ppc TCG, in powerpc_checkstop(), for a machine check exception I think >> >> 1) The Checkstop state is the state the (modern) architecture prescribes >> the machine transitions to when: a) machine check happens but machine >> check exceptions are disabled or b) hard-to-recover storage errors. On >> older user manuals I also see occurrences of checkstop when (a) above >> happens and a "debug bit" is also set. >> >> 603 UM: >> "[cpu] must terminate operation by internally gating off all clocks, and >> release all outputs to the high impedance state" >> >> 750cx UM: >> "When a processor is in checkstop state, instruction processing is >> suspended and generally cannot resume without the processor being >> reset." > > Thanks. So since this is in TCG, is this for the case "we emulated > the CPU ending up in a checkstop situation", rather than "the real > host hardware is broken" ? Can the guest deliberately provoke real > hardware into this state, or is it only something you can get into > when the h/w is broken ? >
The former, checkstop emulation. The guest cannot cause real hardware to be in this state, this is the cosmic rays kind of problem.
