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OSes can use it to detect > > whether the emergency console is available or not. > > > > Fixes: d1bd157fbc9b ("Big merge the HVM full-virtualisation abstractions.") > > Signed-off-by: Roger Pau Monné > > Reviewed-by: Andrew Cooper > > That's been wrong for rather a long time.  How did you find it? I came across the documentation above and I didn't remember Xen returning any value for reads, which sadly was indeed true. This was because I had the intention to suggest Alejandro to (also?) use the port 0xe9 hack for printing from XTF, which should work for both Xen and QEMU. > CC-ing Oleksii as you've tagged this for 4.21. I was told that bugfixes didn't need a release-ack until hard code freeze, which is the 31st of October? Thanks, Roger.