linux-stable-rt/drivers/lguest
Rusty Russell 37250097e1 Fix non-TSC guest clocksource lockup
lguest uses a host-supplied wallclock-based clocksource when the TSC
is not reliable.  As this is already in nanoseconds, I naively used a
multiplier of 1 and a shift of 0.

But update_wall_time() in its infinite wisdom decides to adjust the
clock a little (where does it think it's getting a more accurate time
from?)

It will happily tweak the multiplier... to 0, then -1.

So the "fix" is to use a shift of 22 like everyone else, and a
multiplier of 1 << 22.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-09 08:14:56 -07:00
..
Kconfig Enable lguest drivers in Kconfig 2007-08-06 18:21:15 -07:00
Makefile lguest: documentation I: Preparation 2007-07-26 11:35:16 -07:00
README lguest: documentation I: Preparation 2007-07-26 11:35:16 -07:00
core.c lguest: documentation VI: Switcher 2007-07-26 11:35:17 -07:00
hypercalls.c Provide timespec to guests rather than jiffies clock. 2007-07-28 19:54:33 -07:00
interrupts_and_traps.c Provide timespec to guests rather than jiffies clock. 2007-07-28 19:54:33 -07:00
io.c lguest: documentation VII: FIXMEs 2007-07-26 11:35:17 -07:00
lg.h Provide timespec to guests rather than jiffies clock. 2007-07-28 19:54:33 -07:00
lguest.c Fix non-TSC guest clocksource lockup 2007-08-09 08:14:56 -07:00
lguest_asm.S lguest: documentation VII: FIXMEs 2007-07-26 11:35:17 -07:00
lguest_bus.c lguest: documentation III: Drivers 2007-07-26 11:35:17 -07:00
lguest_user.c lguest: documentation IV: Launcher 2007-07-26 11:35:17 -07:00
page_tables.c lguest: documentation VII: FIXMEs 2007-07-26 11:35:17 -07:00
segments.c lguest: documentation VII: FIXMEs 2007-07-26 11:35:17 -07:00
switcher.S lguest: documentation VI: Switcher 2007-07-26 11:35:17 -07:00

README

Welcome, friend reader, to lguest.

Lguest is an adventure, with you, the reader, as Hero.  I can't think of many
5000-line projects which offer both such capability and glimpses of future
potential; it is an exciting time to be delving into the source!

But be warned; this is an arduous journey of several hours or more!  And as we
know, all true Heroes are driven by a Noble Goal.  Thus I offer a Beer (or
equivalent) to anyone I meet who has completed this documentation.

So get comfortable and keep your wits about you (both quick and humorous).
Along your way to the Noble Goal, you will also gain masterly insight into
lguest, and hypervisors and x86 virtualization in general.

Our Quest is in seven parts: (best read with C highlighting turned on)

I) Preparation
	- In which our potential hero is flown quickly over the landscape for a
	  taste of its scope.  Suitable for the armchair coders and other such
	  persons of faint constitution.

II) Guest
	- Where we encounter the first tantalising wisps of code, and come to
	  understand the details of the life of a Guest kernel.

III) Drivers
	- Whereby the Guest finds its voice and become useful, and our
	  understanding of the Guest is completed.

IV) Launcher
	- Where we trace back to the creation of the Guest, and thus begin our
	  understanding of the Host.

V) Host
	- Where we master the Host code, through a long and tortuous journey.
	  Indeed, it is here that our hero is tested in the Bit of Despair.

VI) Switcher
	- Where our understanding of the intertwined nature of Guests and Hosts
	  is completed.

VII) Mastery
	- Where our fully fledged hero grapples with the Great Question:
	  "What next?"

make Preparation!
Rusty Russell.