[Adding Paolo and Vitaly, but FYI only as the bug seems to have an upstream fix already.]
On Mon, Mar 26, 2018 at 09:13:45AM +0300, Roman Kagan wrote: > On Sat, Mar 24, 2018 at 03:11:12PM +0000, Richard W.M. Jones wrote: > > On Sat, Mar 24, 2018 at 03:08:16PM +0000, Tanmoy Sinha wrote: > > > Even though force_tcg works, I intend not to run it on emulation. Is there > > > way I can run it over kvm? The other observation is, without force_tcg if > > > I > > > use the machine type as *pc-i440fx-2.**1*,accel=kvm it works fine. The > > > default machine type for my host *pc-i440fx-2.8, *which seems to crib. > > > > I don't know, but this is basically a bug in VMware, so you need > > to ask them to fix their nested KVM-on-ESXi use case. > > We've encountered this problem, too. > > Strictly speaking, the bug is not in VMWare, but rather in KVM: on > EPT_MISCONFIG vmexits it assumed the processor to set the instuction > length field. This wasn't mandated by the spec but the real processors > did that. OTOH some hypervisors (VMWare, Hyper-V) didn't do that for > the nested hypervisor. As a result, when handling MMIO the guest > instruction pointer didn't get advanced, i.e. the guest got stuck in an > infinite loop. > > The difference between the old and the new machine type is that the > latter turns on newer virtio protocol version employing MMIO, exposing > this bug. > > The fix is commit d391f1207067268261add0485f0f34503539c5b0 which went > into 4.16-rc1. Can you (Tanmoy) please try a newer kernel inside the VMware guest? Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com libguestfs lets you edit virtual machines. Supports shell scripting, bindings from many languages. http://libguestfs.org _______________________________________________ Libguestfs mailing list [email protected] https://www.redhat.com/mailman/listinfo/libguestfs
