On Tue, Feb 05, 2019 at 03:59:15PM +0100, Greg Kurz wrote: > On Tue, 5 Feb 2019 17:13:46 +1100 > David Gibson <da...@gibson.dropbear.id.au> wrote: > > > On Thu, Jan 17, 2019 at 06:14:46PM +0100, Greg Kurz wrote: > > > The current code assumes that an interrupt is allocated as soon as its > > > type is set to MSI or LSI. PHB hotplug will require to be able to set > > > the type of an interrupt before actually allocating it. > > > > Hm.. why? > > > > The justification for that is given in patch 6 actually: > > Every PHB needs to claim 4 LSIs to support legacy PCI devices. This is > currently done at PHB realize. When using in-kernel XICS (or upcoming > in-kernel XIVE), QEMU synchronizes the state of all irqs, including > these LSIs, later on at machine reset. > > In order to support PHB hotplug, we need a way to tell KVM about the > LSIs that doesn't require a machine reset. Since these irq numbers are > fixed values derived from the PHB index, let's identify them all at > machine init. Older machines that don't have fixed irq numbers cannot > support PHB hotplug and keep the existing behavior.
Sounds good.
> FYI, I'm currently reworking that part entirely. Maybe not worth wasting to
> much time on reviewing this v3.
Ok, I have plenty of other stuff to review, so I'll wait for the next spin.
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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