Re: [Libguestfs] Nested KVM on VMware ESXi failure (was: Re: Issue with libguestfs-test-tool on a guest hosted on VMWare ESXi)

I am trying that out. Debian 9 (stretch) backports still doesn't have 4.16 kernel. So I building the kernel from the source. Will keep you posted. On Mon, 26 Mar 2018 at 13:00 Richard W.M. Jones <rjones(a)redhat.com&gt; wrote: > [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 Libguestfs(a)redhat.com https://www.redhat.com/mailman/listinfo/libguestfs