Re: [Qemu-devel] [RESENT][PATCH 2/2] x86: Issue reset on triple faults

[Jamie Lokier]

Jan Kiszka wrote:
> As discussed a few times on this list: A triple fault causes a system
> reset on x86, and some guests make use of this. To keep the chance of
> tracing unexpected resets, log them if CPU_LOG_RESET is set.

It might be worth distinguishing between
triple-fault-used-by-guest-for-context-switch and triple faults which
trigger a normal reset, and log only the latter.  There's a
standardish way of distinguishing them, which the BIOS should check.

> +#if !defined(CONFIG_USER_ONLY)
> +    if (env->old_exception == EXCP08_DBLE) {
> +        if (env->hflags & HF_SVMI_MASK)
> +            helper_vmexit(SVM_EXIT_SHUTDOWN, 0);
> +
> +        if (loglevel & CPU_LOG_RESET)
> +            fprintf(logfile, "Triple fault\n");
> +
> +        qemu_system_reset_request();
> +        return EXCP_HLT;
> +    }
> +#endif

When helper(SVM_EXIT_SHUTDOWN, 0) is called, should it still also call
qemu_system_reset_request()?

-- Jamie