On Fri, 25 Jan 2019 17:04:04 +0100 Halil Pasic <pasic@xxxxxxxxxxxxx> wrote: > Do we expect userspace/QEMU to fence the bad scenarios as tries to do > today, or is this supposed to change to hardware should sort out > requests whenever possible. Does my other mail answer that? > The problem I see with the let the hardware sort it out is that, for that > to work, we need to juggle multiple translations simultaneously (or am I > wrong?). Doing that does not appear particularly simple to me. None in the first stage, at most two in the second stage, I guess. > Furthermore we would go through all that hassle knowingly that the sole > reason is working around bugs. We still expect our Linux guests > serializing it's ssch() stuff as it does today. Thus I would except this > code not getting the love nor the coverage that would guard against bugs > in that code. So, we should have test code for that? (Any IBM-internal channel I/O exercisers that may help?) We should not rely on the guest being sane, although Linux probably is in that respect.
