On Fri, Dec 07, 2018 at 10:08:20PM +1100, Michael Ellerman wrote: > Suraj Jitindar Singh <sjitindarsingh@xxxxxxxxx> writes: > > > When booting a kvm-pr guest on a POWER9 machine the following message is > > observed: > > "qemu-system-ppc64: KVM does not support 1TiB segments which guest expects" > > > > This is because the guest is expecting to be able to use 1T segments > > however we don't indicate support for it. This is because we don't set > > the BOOK3S_HFLAG_MULTI_PGSIZE flag in the hflags in kvmppc_set_pvr_pr() > > on POWER9. > > > > POWER9 does indeed have support for 1T segments, so add a case for > > POWER9 to the switch statement to ensure it is set. > > If this just checked mmu_has_feature(MMU_FTR_1T_SEGMENT) it would have > been right in this case, and we'd also never have to update it in > future. > > Any reason not to? PR KVM can emulate a different processor from the host. Checking mmu_has_feature() will tell you about the host, not the CPU being emulated. Paul.