[Qemu-devel] [PATCH/RFC 0/4] Rework alarm timer infrastrucure.

[Luca Tettamanti]

Hello,
in reply to this mail I will send a serie of 4 patches that cleans up and 
expands
the alarm timer handling in QEMU. Patches apply to current kvm-userspace tree,
but I think I can rebase it to QEMU svn if desired.

Patch 1 is mostly a cleanup of the existing code; instead of having multiple
#ifdefs to handle different timers scattered all over the code I've created a
modular infrastructure where each timer type is self-contained and generic code
is more readable. The resulting code is functionally equivalent to the old one.

Patch 2 implements the "-clock" command line option proposed by Daniel Berrange
and Avi Kivity. By default QEMU tries RTC and then falls back to unix timer;
user can override the order of the timer through this options. Syntax is pretty
simple: -clock timer1,timer2,etc. (QEMU will pick the first one that works).

Patch 3 adds support for HPET under Linux (which is basically my old patch). As
suggested HPET takes precedence over other timers, but of course this can be
overridden.

Patch 4 introduces "dynticks" timer source; patch is mostly based on the work
Dan Kenigsberg. dynticks is now the default alarm timer.