On 26/11/18 23:43, Michael S. Tsirkin wrote: > On Mon, Nov 26, 2018 at 02:20:38PM +0100, Paolo Bonzini wrote: >> vhost does not have to be supported only if KVM is present, in fact >> vhost-user does not even need any kind of kernel support. This series >> changes this. The rationale is that, when vhost-user-test.c will be >> converted to qgraph, it will be able to test vhost-user support >> for virtio-mmio backend even on x86. > > The reason for limiting it to KVM was very simple: > it has the same set of problems with ordering > as mttcg. > > So I guess it's fine but I think we must then limit it > to when tcg emits fence instructions. > > Otherwise we'll get subtle race conditions.
Got it, I'll take a look. However, right now you _can_ use vhost with tcg as long as e.g. qemu-system-x86_64 is compiled with KVM support, so this patch is not changing anything in this respect; the bug is independent of this series. Paolo
