On Fri, May 16, 2025 at 09:31:42AM +0800, Jason Wang wrote: > On Thu, May 15, 2025 at 2:14 PM Michael S. Tsirkin <m...@redhat.com> wrote: > > > > On Wed, May 14, 2025 at 10:52:58AM +0800, Jason Wang wrote: > > > On Tue, May 13, 2025 at 3:09 PM Michael S. Tsirkin <m...@redhat.com> > > > wrote: > > > > > > > > On Tue, May 13, 2025 at 12:08:51PM +0800, Jason Wang wrote: > > > > > On Wed, Apr 30, 2025 at 5:27 PM Michael S. Tsirkin <m...@redhat.com> > > > > > wrote: > > > > > > > > > > > > On Wed, Apr 30, 2025 at 11:34:49AM +0800, Jason Wang wrote: > > > > > > > On Tue, Apr 29, 2025 at 6:56 PM Michael S. Tsirkin > > > > > > > <m...@redhat.com> wrote: > > > > > > > > > > > > > > > > On Tue, Apr 29, 2025 at 11:39:37AM +0800, Jason Wang wrote: > > > > > > > > > On Mon, Apr 21, 2025 at 11:46 AM Jason Wang > > > > > > > > > <jasow...@redhat.com> wrote: > > > > > > > > > > > > > > > > > > > > On Mon, Apr 21, 2025 at 11:45 AM Jason Wang > > > > > > > > > > <jasow...@redhat.com> wrote: > > > > > > > > > > > > > > > > > > > > > > On Mon, Apr 21, 2025 at 10:45 AM Cindy Lu > > > > > > > > > > > <l...@redhat.com> wrote: > > > > > > > > > > > > > > > > > > > > > > > > Introduce a new config knob > > > > > > > > > > > > `CONFIG_VHOST_ENABLE_FORK_OWNER_IOCTL`, > > > > > > > > > > > > to control the availability of the > > > > > > > > > > > > `VHOST_FORK_FROM_OWNER` ioctl. > > > > > > > > > > > > When CONFIG_VHOST_ENABLE_FORK_OWNER_IOCTL is set to n, > > > > > > > > > > > > the ioctl > > > > > > > > > > > > is disabled, and any attempt to use it will result in > > > > > > > > > > > > failure. > > > > > > > > > > > > > > > > > > > > > > I think we need to describe why the default value was > > > > > > > > > > > chosen to be false. > > > > > > > > > > > > > > > > > > > > > > What's more, should we document the implications here? > > > > > > > > > > > > > > > > > > > > > > inherit_owner was set to false: this means "legacy" > > > > > > > > > > > userspace may > > > > > > > > > > > > > > > > > > > > I meant "true" actually. > > > > > > > > > > > > > > > > > > MIchael, I'd expect inherit_owner to be false. Otherwise > > > > > > > > > legacy > > > > > > > > > applications need to be modified in order to get the behaviour > > > > > > > > > recovered which is an impossible taks. > > > > > > > > > > > > > > > > > > Any idea on this? > > > > > > > > > > > > > > > > > > Thanks > > > > > > > > > > > > So, let's say we had a modparam? Enough for this customer? > > > > > > WDYT? > > > > > > > > > > Just to make sure I understand the proposal. > > > > > > > > > > Did you mean a module parameter like "inherit_owner_by_default"? I > > > > > think it would be fine if we make it false by default. > > > > > > > > > > Thanks > > > > > > > > I think we should keep it true by default, changing the default > > > > risks regressing what we already fixes. > > > > > > I think it's not a regression since it comes since the day vhost is > > > introduced. To my understanding the real regression is the user space > > > noticeable behaviour changes introduced by vhost thread. > > > > > > > The specific customer can > > > > flip the modparam and be happy. > > > > > > If you stick to the false as default, I'm fine. > > > > > > Thanks > > > > That would be yet another behaviour change. > > Back to the original behaviour.
yes but the original was also a bugfix. > > I think one was enough, don't you think? > > I think such kind of change is unavoidable if we want to fix the > usersapce behaviour change. > > Thanks I feel it is too late to "fix". the new behaviour is generally ok, and I feel the right thing so to give management control knobs do pick the desired behaviour. And really modparam is wrong here because different userspace can have different requirements, and in ~10 years I want to see us disable the legacy behaviour altogether. But given your time constraints, a modparam knob as a quick workaround for the specific customer is kind of not very terrible. > > > > > > > > > > > > > > > > > > > > -- > > > > > > MST > > > > > > > > > > > >
