On Wednesday 24 September 2008 17:22:53 Avi Kivity wrote: > Yang, Sheng wrote: > >> We only have three pci interrupts at this point (though this could be > >> easily extended); if you start the guest with a non-trivial number of > >> devices, you will have shared guest interrupts. > >> > >> (of course, when I pointed this out during review, people said it could > >> be done later, then forgot all about it) > > > > ..... > > > > I think it's a performance issue, not break it? How about do it like Xen > > side? Try best to avoid the share, extended the pci interrupts, improve > > hash algorithm. Is there anything else we can do? > > Two separate issues: > > 1. only three guest pci interrupts > > That's a performance issue, not correctness. can be fixed by using gsi > 16-23 in APIC mode, and by adding another IOAPIC (so we can use gsi > 16-47). Anthony Xu posted some patches for this, not sure where this > stands, but it was the right approach. > > 2. shared guest pci interrupts > > That's a correctness issue. No matter how many interrupts we have, we > may have sharing issues. Of course with only three the issue is very > pressing since we will get sharing with just a few devices. Currently > if two assigned devices share a guest interrupts, or if an emulated > device shares an interrupt with an assigned device, things will break. > > They need to be fixed independently.
About the second issue, I don't understand how it would break... Would you please give more details on this? It's a QEmu bug or IOAPIC bug? -- regards Yang, Sheng -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
