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It turns out that the console does seem to work fine, even with memory decoding disabled on the device (as expected). I've updated the firmware in the meantime, so I'm unsure whether that update has changed the behavior of the device, or it simply was some other instability that was causing the issue in the past. This SOL AMT device is not reliable at all I'm afraid. > As mentioned, > us driving the device generally means we're free to do whatever we want to > the command register, as long as resulting device state is consistent > overall (or else we may indeed have a non-working device). Having to keep > memory decoding enabled in order for I/O ports to function is pretty > clearly a bug in the device, and hence us "violating" that requirement > isn't really o bug of ours. I think given the fragility of some of those SOL devices it's best to limit the number of bits Xen changes, as to having a bigger chances of getting output working. Thanks, Roger.