Hi Peter, On Tue, Jul 24, 2018 at 1:55 AM Peter Xu <pet...@redhat.com> wrote: > > On Mon, Jul 23, 2018 at 04:13:18PM -0400, Jintack Lim wrote: > > Hi, > > > > I'm running a Windows VM on top of KVM on x86, and one of virtio-net > > device in the Windows VM doesn't seem to work. I provided virtual > > IOMMU and two virtio-net devices to the VM: one bypassing the virtual > > IOMMU and the other one behind the virtual IOMMU[1]. It turned out > > that the virtio-net device behind virtual IOMMU didn't work while the > > one bypassing the virtual IOMMU worked well. In a linux VM with the > > same configuration, both of virtio-net device worked well. > > > > I found that there is a subtle difference between virtio-net devices > > bypassing and behind virtual IOMMU in a Linux VM. The lscpu command in > > the Linux VM shows different device names for them; the first line is > > for the bypassing one, and the second line is for the one behind the > > virtual IOMMU > > > > 00:03.0 Ethernet controller: Red Hat, Inc Virtio network device > > 01:00.0 Ethernet controller: Red Hat, Inc Device 1041 (rev 01) > > > > I wonder if this difference somehow caused the problem in the Windows > > VM. I've installed the latest virtio drivers (0.1.149) from the fedora > > project [2] > > > > Any thoughts? > > > > I'm using v4.15 Linux kernel as a host, and QEMU 2.11.0. > > Have you tried the latest QEMU? >
I just tried the latest QEMU, but observed the same symptom. > Also CC Jason and Michael. Thanks! > > > > > Thanks, > > Jintack > > > > [1] https://wiki.qemu.org/Features/VT-d > > [2] > > https://docs.fedoraproject.org/quick-docs/en-US/creating-windows-virtual-machines-using-virtio-drivers.html > > > > > > Regards, > > -- > Peter Xu >
