On Thu, Feb 2, 2023 at 2:00 AM Si-Wei Liu <si-wei....@oracle.com> wrote: > > > > On 1/12/2023 9:24 AM, Eugenio Pérez wrote: > > It's possible to migrate vdpa net devices if they are shadowed from the > > > > start. But to always shadow the dataplane is effectively break its host > > > > passthrough, so its not convenient in vDPA scenarios. > > > > > > > > This series enables dynamically switching to shadow mode only at > > > > migration time. This allow full data virtqueues passthrough all the > > > > time qemu is not migrating. > > > > > > > > Successfully tested with vdpa_sim_net (but it needs some patches, I > > > > will send them soon) and qemu emulated device with vp_vdpa with > > > > some restrictions: > > > > * No CVQ. > > > > * VIRTIO_RING_F_STATE patches. > What are these patches (I'm not sure I follow VIRTIO_RING_F_STATE, is it > a new feature that other vdpa driver would need for live migration)? >
Not really, Since vp_vdpa wraps a virtio-net-pci driver to give it vdpa capabilities it needs a virtio in-band method to set and fetch the virtqueue state. Jason sent a proposal some time ago [1], and I implemented it in qemu's virtio emulated device. I can send them as a RFC but I didn't worry about making it pretty, nor I think they should be merged at the moment. vdpa parent drivers should follow vdpa_sim changes. Thanks! [1] https://lists.oasis-open.org/archives/virtio-comment/202103/msg00036.html > -Siwei > > > > > * Expose _F_SUSPEND, but ignore it and suspend on ring state fetch like > > > > DPDK. > > > > > > > > Comments are welcome, especially in the patcheswith RFC in the message. > > > > > > > > v2: > > > > - Use a migration listener instead of a memory listener to know when > > > > the migration starts. > > > > - Add stuff not picked with ASID patches, like enable rings after > > > > driver_ok > > > > - Add rewinding on the migration src, not in dst > > > > - v1 at https://lists.gnu.org/archive/html/qemu-devel/2022-08/msg01664.html > > > > > > > > Eugenio Pérez (13): > > > > vdpa: fix VHOST_BACKEND_F_IOTLB_ASID flag check > > > > vdpa net: move iova tree creation from init to start > > > > vdpa: copy cvq shadow_data from data vqs, not from x-svq > > > > vdpa: rewind at get_base, not set_base > > > > vdpa net: add migration blocker if cannot migrate cvq > > > > vhost: delay set_vring_ready after DRIVER_OK > > > > vdpa: delay set_vring_ready after DRIVER_OK > > > > vdpa: Negotiate _F_SUSPEND feature > > > > vdpa: add feature_log parameter to vhost_vdpa > > > > vdpa net: allow VHOST_F_LOG_ALL > > > > vdpa: add vdpa net migration state notifier > > > > vdpa: preemptive kick at enable > > > > vdpa: Conditionally expose _F_LOG in vhost_net devices > > > > > > > > include/hw/virtio/vhost-backend.h | 4 + > > > > include/hw/virtio/vhost-vdpa.h | 1 + > > > > hw/net/vhost_net.c | 25 ++- > > > > hw/virtio/vhost-vdpa.c | 64 +++++--- > > > > hw/virtio/vhost.c | 3 + > > > > net/vhost-vdpa.c | 247 +++++++++++++++++++++++++----- > > > > 6 files changed, 278 insertions(+), 66 deletions(-) > > > > > > >
