On 2/2/2023 3:27 AM, Eugenio Perez Martin wrote:
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.
Got it. No bother sending RFC for now, I think it's limited to virtio
backed vdpa providers only. Thanks for the clarifications.
-Siwei
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(-)
