On Fri, May 17, 2024 at 09:53:36AM +0200, Fiona Ebner wrote: > Migration from an 8.2 or 9.0 binary to an 8.1 binary with machine > version 8.1 can fail with: > > > kvm: Features 0x1c0010130afffa7 unsupported. Allowed features: 0x10179bfffe7 > > kvm: Failed to load virtio-net:virtio > > kvm: error while loading state for instance 0x0 of device > > '0000:00:12.0/virtio-net' > > kvm: load of migration failed: Operation not permitted > > The series > > 53da8b5a99 virtio-net: Add support for USO features > 9da1684954 virtio-net: Add USO flags to vhost support. > f03e0cf63b tap: Add check for USO features > 2ab0ec3121 tap: Add USO support to tap device. > > only landed in QEMU 8.2, so the compatibility flags should be part of > machine version 8.1. > > Moving the flags unfortunately breaks forward migration with machine > version 8.1 from a binary without this patch to a binary with this > patch. >
I think it'll be nicer we always copy stable in the commit log, so that "whether to copy stable" is stick with the patch: Cc: qemu-stable <qemu-sta...@nongnu.org> Even though it's not required for qemu stable process (I'd say that's because we have a good stable tree maintainer..). So we need this in qemu 8.1, 8.2 and 9.0? > Fixes: 53da8b5a99 ("virtio-net: Add support for USO features") > Signed-off-by: Fiona Ebner <f.eb...@proxmox.com> Reviewed-by: Peter Xu <pet...@redhat.com> > --- > hw/core/machine.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/hw/core/machine.c b/hw/core/machine.c > index c7ceb11501..95051b80db 100644 > --- a/hw/core/machine.c > +++ b/hw/core/machine.c > @@ -50,15 +50,15 @@ GlobalProperty hw_compat_8_1[] = { > { "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); > > GlobalProperty hw_compat_8_0[] = { > { "migration", "multifd-flush-after-each-section", "on"}, > { TYPE_PCI_DEVICE, "x-pcie-ari-nextfn-1", "on" }, > - { TYPE_VIRTIO_NET, "host_uso", "off"}, > - { TYPE_VIRTIO_NET, "guest_uso4", "off"}, > - { TYPE_VIRTIO_NET, "guest_uso6", "off"}, > }; > const size_t hw_compat_8_0_len = G_N_ELEMENTS(hw_compat_8_0); > > -- > 2.39.2 > > > -- Peter Xu