Re: [virtio-comment] [PATCH 0/5] virtio: introduce SUSPEND bit and vq state

["Zhu, Lingshan" <lingshan.zhu@intel.com>]

On 9/6/2023 4:29 PM, Michael S. Tsirkin wrote:
> On Wed, Sep 06, 2023 at 04:16:32PM +0800, Zhu Lingshan wrote:
> > This series introduces
> > 1)a new SUSPEND bit in the device status
> > Which is used to suspend the device, so that the device states
> > and virtqueue states are stabilized.
> >
> > 2)virtqueue state and its accessor, to get and set last_avail_idx
> > and last_used_idx of virtqueues.
> >
> > The main usecase of these new facilities is Live Migration.
> >
> > Future work: dirty page tracking and in-flight descriptors.
> oh that answers my question - it's not covered.
> I don't think we can merge this without in-flight descriptor
> support.
When SUSPEND, we require the device wait until all descriptors that
being processed to finish and mark them as used.(In patch 2)

at this point there may be no in-flight descriptors, so this is still
self-consistent. The tracker for in-flight descriptors is excluded to
make this series small and focus.
> > This series addresses many comments from Jason, Stefan and Eugenio
> > from RFC series.
> >
> > Zhu Lingshan (5):
> >    virtio: introduce vq state as basic facility
> >    virtio: introduce SUSPEND bit in device status
> >    virtqueue: constraints for virtqueue state
> >    virtqueue: ignore resetting vqs when SUSPEND
> >    virtio-pci: implement VIRTIO_F_QUEUE_STATE
> >
> >   content.tex       | 118 ++++++++++++++++++++++++++++++++++++++++++++++
> >   transport-pci.tex |  18 +++++++
> >   2 files changed, 136 insertions(+)
> >
> > --
> > 2.35.3
> >
> >
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