KVM: In-kernel PIT model

Hi,

Here is the updated in-kernel PIT model. The main improvements are:

1. The support of SMP PAE host is OK now.

2. The strategy of inject timer interrupt changed. To prevent much more interrupt injection in some SMP guest(for example, more than 50k trying for 1k interrupts per second), the strategy was changed to try to ensure last interrupt was injected, then inject the next one. Also add time out to in case of interrupts lost.

3. Find a bug of QEMU PIT causing a little more PIT interrupts were injected(36.4 interrupts were injected per second, causing 2.6.16 guest timer run faster more than 1/10). Disable QEMU PIT now.

The test result is pretty well with both UP and SMP guest, mostly with default kernel paramters. But RHEL5/5.1 SMP
PAE guest need "clocksource=pit" to make it stable, otherwise may meet the same problem in currently RHEL5.1 SMP PAE guest. If hang occurs, seems only the time out part of PIT interrupts would be injected. For seems it's due to other clocksource, I would check that later.

Thanks
Yang, Sheng

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Looking good; apart from some very minor comments all that is missing is save/restore support.

error compiling committee.c: too many arguments to function


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