On 17 June 2014 22:32, Benjamin Herrenschmidt <b...@kernel.crashing.org> wrote: > Additionally, I wouldn't mind of we did a quick "trick" equivalent (but > cleaner) to what I did in my patch which is when the pseries guest calls > the hypervisor call to change the interrupt endian mode, we notify VGA > and switch its endian mode, so we work "by default" with kernels not > updated to know about that register. But this is open for debate. It's > somewhat "acceptable" in the context of our hypercall being a > "paravirtualized" interface, so it can be argued that the hypercall > poking at the VGA chip is equivalent to some FW doing so :-)
I'm definitely against this. Have your guest change the behaviour of the VGA device by explicitly prodding the VGA device, not by back-door side-effects of something else that it happens to do on one particular guest for one particular architecture, please. thanks -- PMM
