WSL2-Linux-Kernel/drivers/lguest
Rusty Russell 6e5aa7efb2 virtio: reset function
A reset function solves three problems:

1) It allows us to renegotiate features, eg. if we want to upgrade a
   guest driver without rebooting the guest.

2) It gives us a clean way of shutting down virtqueues: after a reset,
   we know that the buffers won't be used by the host, and

3) It helps the guest recover from messed-up drivers.

So we remove the ->shutdown hook, and the only way we now remove
feature bits is via reset.

We leave it to the driver to do the reset before it deletes queues:
the balloon driver, for example, needs to chat to the host in its
remove function.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-02-04 23:50:03 +11:00
..
x86 lguest: fix mis-merge against hpa's TSS renaming 2008-01-31 19:59:44 +11:00
Kconfig Remove bogus duplicate CONFIG_LGUEST_GUEST entry. 2008-01-19 21:29:39 -08:00
Makefile Lguest support for Virtio 2007-10-23 15:49:56 +10:00
README lguest: documentation I: Preparation 2007-07-26 11:35:16 -07:00
core.c lguest: get rid of lg variable assignments 2008-01-30 22:50:18 +11:00
hypercalls.c lguest: Use explicit includes rateher than indirect 2008-01-30 22:50:19 +11:00
interrupts_and_traps.c lguest: get rid of lg variable assignments 2008-01-30 22:50:18 +11:00
lg.h lguest: Use explicit includes rateher than indirect 2008-01-30 22:50:19 +11:00
lguest_device.c virtio: reset function 2008-02-04 23:50:03 +11:00
lguest_user.c lguest: Use explicit includes rateher than indirect 2008-01-30 22:50:19 +11:00
page_tables.c lguest: use __PAGE_KERNEL instead of _PAGE_KERNEL 2008-01-30 22:50:19 +11:00
segments.c lguest: get rid of lg variable assignments 2008-01-30 22:50:18 +11:00

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.