Re: [Qemu-devel] [PATCH 1/3] Revert "vhost: rename VHOST_RESET_OWNER to VHOST_RESET_DEVICE"

[Michael S. Tsirkin]

On Wed, Oct 21, 2015 at 05:21:40PM +0800, Yuanhan Liu wrote:
> On Wed, Oct 21, 2015 at 12:15:52PM +0300, Michael S. Tsirkin wrote:
> > On Wed, Oct 21, 2015 at 04:55:16PM +0800, Yuanhan Liu wrote:
> > > On Fri, Oct 16, 2015 at 10:47:49AM +0300, Michael S. Tsirkin wrote:
> > > > On Fri, Oct 16, 2015 at 03:32:56PM +0800, Yuanhan Liu wrote:
> > > > > On Fri, Oct 16, 2015 at 10:21:40AM +0300, Michael S. Tsirkin wrote:
> > > > > > On Fri, Oct 16, 2015 at 03:18:59PM +0800, Yuanhan Liu wrote:
> > > > > > > This reverts commit d1f8b30ec8dde0318fd1b98d24a64926feae9625.
> > > > > > > 
> > > > > > > It turned out that it breaks stuff, so revert it:
> > > > > > > 
> > > > > > >     
> > > > > > > http://lists.nongnu.org/archive/html/qemu-devel/2015-10/msg00949.html
> > > > > > > 
> > > > > > > CC: "Michael S. Tsirkin" <address@hidden>
> > > > > > > Reported-by: Paolo Bonzini <address@hidden>
> > > > > > > Signed-off-by: Yuanhan Liu <address@hidden>
> > > > > > 
> > > > > > OK but that's not enough. We need to also
> > > > > > - drop patch sending this on stop
> > > > > 
> > > > > I could do that. But may I know why we have to drop it on stop?
> > > > 
> > > > Because we need to get the state from remote after stop.
> > > > RESET_OWNER discards that, so we can't resume the VM.
> > > > 
> > > > > If we don't send it on stop, when will we send it? The termination
> > > > > of QEMU?
> > > > 
> > > > If mq is negotiated, we don't need it.  If mq isn't negotiated, maybe we
> > > > should send it on reset/driver unload.
> > > 
> > > Sorry, what place do you mean exactly?
> > 
> > There's no such code - you'll have to add
> > a callback into vhost from virtio.
> 
> Say, at virtio_net_reset()?
> 
>       --yliu

Sounds good.

> > > 
> > > > It might be better than
> > > > corrupting guest memory. And if we do, maybe we should keep
> > > > the RESET_DEVICE name.