kernel-ark/drivers/lguest
Rusty Russell a489f0b555 lguest: fix guest crash on non-linear addresses in gdt pvops
Fixes guest crash 'lguest: bad read address 0x4800000 len 256'

The new per-cpu allocator ends up handing a non-linear address to
write_gdt_entry.  We do __pa() on it, and hand it to the host, which
kills us.

I've long wanted to make the hypercall "LOAD_GDT_ENTRY" to match the IDT
code, but had no pressing reason until now.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: lguest@ozlabs.org
2009-04-19 23:14:01 +09:30
..
x86 lguest: fix guest crash on non-linear addresses in gdt pvops 2009-04-19 23:14:01 +09:30
core.c lguest: use bool instead of int 2009-03-30 21:55:25 +10:30
hypercalls.c lguest: comment documentation update. 2008-03-28 11:05:54 +11:00
interrupts_and_traps.c lguest: use bool instead of int 2009-03-30 21:55:25 +10:30
Kconfig x86: remove the Voyager 32-bit subarch 2009-02-23 00:54:01 +01:00
lg.h lguest: fix guest crash on non-linear addresses in gdt pvops 2009-04-19 23:14:01 +09:30
lguest_device.c lguest: use KVM hypercalls 2009-03-30 21:55:24 +10:30
lguest_user.c lguest: Fix a memory leak with the lg object during launcher close 2009-01-30 11:34:11 +10:30
Makefile lguest: Add puppies which where previously missing. 2008-03-28 11:05:52 +11:00
page_tables.c lguest: use bool instead of int 2009-03-30 21:55:25 +10:30
README lguest: documentation I: Preparation 2007-07-26 11:35:16 -07:00
segments.c lguest: fix guest crash on non-linear addresses in gdt pvops 2009-04-19 23:14:01 +09:30

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.