Hi Jason, On Fri, Nov 7, 2025 at 2:02 AM Jason Wang <[email protected]> wrote: > > On Thu, Nov 6, 2025 at 10:28 PM Jinpu Wang <[email protected]> wrote: > > > > Hi Peter, > > On Wed, Nov 5, 2025 at 11:17 PM Peter Xu <[email protected]> wrote: > > > > > > On Wed, Nov 05, 2025 at 10:27:59AM +0100, Jinpu Wang wrote: > > > > > > These are not present (or not supported) on QEMU 8.2.10, which > > > > > > causes > > > > > > the migration state load to fail. > > > > > > > > > > Interesting, we've already done the compat work: > > > > > > > > > > GlobalProperty hw_compat_8_1[] = { > > > > > { TYPE_PCI_BRIDGE, "x-pci-express-writeable-slt-bug", "true" }, > > > > > { "ramfb", "x-migrate", "off" }, > > > > > { "vfio-pci-nohotplug", "x-ramfb-migrate", "off" }, > > > > > { "igb", "x-pcie-flr-init", "off" }, > > > > > { TYPE_VIRTIO_NET, "host_uso", "off"}, > > > > > { TYPE_VIRTIO_NET, "guest_uso4", "off"}, > > > > > { TYPE_VIRTIO_NET, "guest_uso6", "off"}, > > > > > }; > > > > > const size_t hw_compat_8_1_len = G_N_ELEMENTS(hw_compat_8_1); > > > > Yeah, I noticed the same. > > > > > > AFAICT, this is a known issue.. > > > > > > Thomas and I used to suggest we should not turn on USO* by default by > > > probing kernel, but only allow user choosing it explicitly in a VM > > > setup. IOW, dest qemu should stop booting at all when kernel is too old > > > (when user chose the feature). > > I feel this is the approach we should have picked. > > > > > > See: > > > > > > https://lore.kernel.org/all/ZqQNKZ9_OPhDq2AK@x1n/ > > Is there any effort to allow migration from new OS support the USO > > features to old OS doesn't support it? > > You can teach your management to disable USO via the qemu command line.
I added "host_uso=false,guest_uso4=false,guest_uso6=false" for -device virtio-net-pci But migration still fails with slightly different error: char device redirected to /dev/pts/1 (label charserial0) 2025-11-07T15:00:45.528098Z qemu-8.2: Features 0x10130afffa7 unsupported. Allowed features: 0x179bfffe7 2025-11-07T15:00:45.528245Z qemu-8.2: Failed to load virtio-net:virtio 2025-11-07T15:00:45.528253Z qemu-8.2: error while loading state for instance 0x0 of device '0000:00:02.0:06.0/virtio-net' I suppose it is VIRTIO_F_RING_RESET? Any idea? I didn't find option to disable it > > > Any hint to make it work? > > Thanks Thx! > > > > > > > Thanks, > > > > > > -- > > > Peter Xu > > > > > Thx for the help. > > >
