[PATCH v3 0/3] Move RTC interrupt injection back into the vpt code.

[Andrew Cooper <andrew.cooper3@citrix.com>]

Hi,

This series implements the most recent idea Tim was proposing about
reworking the RTC PF interrupt injection.

Patch 1 switches handling the !PIE case to calculate the right answer
for REG_C.PF on demand rather than running the timers.
Patch 2 switches back to the old model of having the vpt code control
the timer interrupt injection; this is the fix for the w2k3 hang.
Patch 3 is just a minor cleanup, and not particularly necessary.

v3 has undergone extensive testing in XenRT, confirming that the w2k3
has not reoccurred in 100 tests (normally expect to see 10-30
recurrences), and the clock drift tests are happy with the new code.

Roger:
  Would you kindly test against FreeBSD again please?

George:
  Regarding 4.4, I believe these patches are now of sufficient
  quality to be accepted (subject to any other review).

  The previous statements of risk still applies; These are changes to
  a very complicated area of code, and the worst case scenario is that
  a VM gets none/too few/too many timing interrupts, with possible
  clock drift as a problem.  The XenRT test results help alleviate
  concern regarding the worst case.

~Andrew