On Thu, Sep 21, 2023 at 12:11 PM Parav Pandit <pa...@nvidia.com> wrote: > > > > > From: Jason Wang <jasow...@redhat.com> > > Sent: Thursday, September 21, 2023 9:32 AM > > > > On Thu, Sep 21, 2023 at 11:51 AM Parav Pandit <pa...@nvidia.com> wrote: > > > > > > > > > > > > > From: Jason Wang <jasow...@redhat.com> > > > > Sent: Thursday, September 21, 2023 8:45 AM The main issue I see so > > > > far is that you want to couple migration with admin commands but I > > > > don't see much advantages to doing this. > > > > > > > The way I read above comment is, to draw a parallel line: descriptor > > > posting in > > virtio spec is tied to virtqueues. What is the advantage of it? > > > > Are you saying virtio can't live without admin commands? Again, let's not > > shift > > concepts. > > > No, I did not say that. > I just don’t see how functionalities proposed in [1] can be done without > admin commands by the _device_ for member device passthrough requirement. > > You made point as "don’t see much advantage with migration done using admin > commands".
Parav, I think I've clarified several times: migration using the admin command is probably fine in some use cases. What's not fine, is: Mandate the admin command to be the only way for migration. Are we on the same page for my concern now? > What is the advantage of descriptor posting using virtqueue. It is the way of > virtio spec... > > > > Well, it is one way to achieve it. > > > There may be different way to do all bulk data transfer without admin > > commands. > > > > Why is virtqueue the only way to do bulk data transferring? Can't DMA be > > initiated by other-way? > > > > Sure, what is the disadvantage of existing mechanism of virtqueue that can do > following. > 1. Ability to do DMA > 2. agnostic of the DMA who do not want to do DMA I don't understand this. > 3. Ability to multiple command executions in parallel Each device has their self-contained interface, why can't the commands be executed in parallel. > 4. Non blocking interface for driver that does not require any kind of polling Are you saying the interrupt can only work for virtqueue? > > Why to invent new DMA scheme which at does all the 4 tasks? It's simply because admin virtqueue can not work for all the cases. I think you've agreed on this, no? > First please list down disadvantages of admin queue + show all 4 things are > achieved using new DMA interface. > That will help to understand why new dma interface is needed. I can give you a simple example. For example, what happens if we want to migrate the owner? Having another owner for this owner is not a good answer. Thanks > > > > > Thanks > > > > > What it the advantage of it, please list down them in [1] for the command > > where you can find alternative. > > > > > > [1] > > > https://lore.kernel.org/virtio-comment/20230909142911.524407-7-parav@n > > > vidia.com/T/#md9fcfa1ba997463de8c7fb8c6d1786b224b0bead > --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscr...@lists.oasis-open.org For additional commands, e-mail: virtio-dev-h...@lists.oasis-open.org
