Upcoming Secure VM support for pSeries machines introduces some complications for virtio, since the transfer buffers need to be explicitly shared so that the hypervisor can access them.
While it's not strictly speaking dependent on it, the fact that virtio devices bypass normal platform IOMMU translation complicates the issue on the guest side. Since there are some significan downsides to bypassing the vIOMMU anyway, let's just disable that. There's already a flag to do this in virtio, just turn it on by default for forthcoming pseries machine types. Any opinions on whether dropping support for the older guest kernels is acceptable at this point? Changes since v2: * Rebase and improve some comments Changes since v1: * Added information on which guest kernel versions will no longer work with these changes * Use Michael Tsirkin's suggested better way of handling the machine type change David Gibson (2): spapr: Disable legacy virtio devices for pseries-5.0 and later spapr: Enable virtio iommu_platform=on by default hw/ppc/spapr.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) -- 2.24.1