> > From: Michael S. Tsirkin <m...@redhat.com> > > Sent: Wednesday, February 8, 2023 12:39 PM > > > > On Wed, Feb 08, 2023 at 05:30:28PM +0000, Parav Pandit wrote: > > > > From: Michael S. Tsirkin <m...@redhat.com> > > > > Sent: Tuesday, February 7, 2023 9:18 AM > > > > > > > > Why migration generate too many spurious interrupts? > > > > > > > > Because, you might want to migrate from hardware with to hardware > > > > without coalescing features. So you just tell guest "sure I will > > > > coalesce" but in fact send interrupts normally. > > > > > > For the hardware that has fake coalescing, HV wouldn't know it anyway > > without doing pre verification. > > > And HV may not migrate in such case for best experience. > > > HV may choose to migrate with low accuracy as you say, which is fine. > > > > > > But the spec guidance for the device implementations is to promote some > > reasonable level of accuracy. > > > Hard to define in words here. > > > Best effort is wide spectrum of range. :) > > > > > > Typically, we say in the spec as SHOULD. > > > So, lets skip the best-effort wording and stick to SHOULD part like rest > > > of the > > spec. > > > > I think the point of best-effort is that driver must handle interrupts that > > arrive > > earlier. > Ok. so Let's put this must requirement in the driver section like the rest.
But this requirement is already written in "Driver Requirements: Used Buffer Notification Suppression". Handling spurious interrupts is not NOTF_COAL specific, but generic, regardless of NOTF_COAL. So I don't think that this should be written in the NOTF_COAL driver section. > > This is how we used it elsewhere. > In a quick grep I see best effort shows two matches one for rx filter and one > for vlan. > Vlan we lately know was (close) to incorrect. > > > What else does it include in your > > opinion that we absolutely must exclude? > > I feel it's a good fit for a non-conformance section which is by nature a > > bit > > informal. > > > > For a conformance section SHOULD is indeed a good fit. > > > Yes, must in driver section and should in device section looks good to me too. The whole NOTF_COAL section is about explaining when a device should issue an interrupt and when not, so writing "The device SHOULD NOT issue an interrupt when it's not supposed to" seems a bit redundant to me. --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscr...@lists.oasis-open.org For additional commands, e-mail: virtio-dev-h...@lists.oasis-open.org
