On Tue, 3 Mar 2020 20:18:18 +0100 Cédric Le Goater <clg@xxxxxxxx> wrote: > >> **** BTW: I figured, I dont need this intermin patch to disable xive for > >> secure VM. Just doing "svm=on xive=off" on the kernel command line is > >> sufficient for now. ***** > >> > > > > No it is not. If the hypervisor doesn't propose XIVE (ie. ic-mode=xive > > on the QEMU command line), the kernel simply ignores "xive=off". > Ah... sorry for the typo... "doesn't propose XICS" of course :) > If I am correct, with the option ic-mode=xive, the hypervisor will > propose only 'xive' in OV5 and not both 'xive' and 'xics'. But the > result is the same because xive can not be turned off and "xive=off" > is ignored. > > Anyway, it's not the most common case of usage of the QEMU command > like. I think it's OK to use "xive=off" on the kernel command line > for now. > Sure, I just wanted to make things clear. Like you said it's a chicken switch introduced for distro testing. I think it should not be used to do anything else. If "svm=1" needs to enforce supported.xive == false as a temporary workaround, it should do it explicitly. > C.
