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Anthony Liguori points out that three different transports use the virtio code, but each one keeps its own counter to set the virtio_device's index field. In theory (though not in current practice) this means that names could be duplicated, and that risk grows as more transports are created. So we move the selection of the unique virtio_device.index into the common code in virtio.c, which has the side-benefit of removing duplicate code. The only complexity is that lguest and S/390 use the index to uniquely identify the device in case of catastrophic failure before register_virtio_device() is called: now we use the offset within the descriptor page as a unique identifier for the printks. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Carsten Otte <cotte@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Chris Lalancette <clalance@redhat.com> Cc: Anthony Liguori <anthony@codemonkey.ws> |
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| .. | ||
| x86 | ||
| core.c | ||
| hypercalls.c | ||
| interrupts_and_traps.c | ||
| Kconfig | ||
| lg.h | ||
| lguest_device.c | ||
| lguest_user.c | ||
| Makefile | ||
| page_tables.c | ||
| README | ||
| segments.c | ||
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.