DOC PREVIEW
UT EE 382V - A comparison of software and hardware techniques for x86 virtualization

This preview shows page 1-2 out of 6 pages.

Save
View full document
View full document
Premium Document
Do you want full access? Go Premium and unlock all 6 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 6 pages.
Access to all documents
Download any document
Ad free experience
Premium Document
Do you want full access? Go Premium and unlock all 6 pages.
Access to all documents
Download any document
Ad free experience

Unformatted text preview:

ReferencesIntroductionWhat is virtual machine?Why use virtual machine?Paper discussionWhat is the problem being solved?Who are the intended users?What is unique about the suggested solution?How is the idea evaluated?Was the evaluation in line with the stated user requirements?Was technology a factor in the problem or solution?Were new tools or software techniques introduced?How may users with other requirements be affected?How can the discussion of this paper be generalized in the context of the class?EE382V: Computer Architecture: User System Interplay Lecture #5Department of Electical and Computer EngineeringThe University of Texas at Austin Saturday, 10 February 2007Disclaimer: ”The contents of this document are scribe notes f or The University ofTexas at Austin EE382V Spring 2007, Co mputer Architecture: User System Interplay∗.The notes capture the class discussion and may contain erroneous and unverified infor-mation and comments.GPP virtualization: A comparison of software andhardware techniqu es for x86 virtualizationLecture #5: Monday, 5 February 2007Lecturer: Mattan ErezScribe: Denis GudovskiyReviewer: Min Kyu Jeong1 ReferencesM. Ro senblum, ”The Reincarnation of Virtual Machines”, ACM Queue vol. 2, no. 5.(background paper).K. Adams and O. Agesen, ”A comparison of software a nd hardware techniques for x86 virtualization”,ASPLOS-XII (required paper).2 IntroductionPresentation: George Abraham and Kyle Cullen2.1 What is v irtual machine?Initially, virtual machine ( VM) meant a software abstraction with t he looks of a com-puter system’s hardware. Now, VM can be seen as a layered abstraction over variousplaces in the system including following levels of virtualization: hardware–level, operat-ing system–level, and high–level language VMs.Hardwa re–level approach was the first attempt to implement virtualization. Several hard-wa r e VMs were built between 1960’s and 1970’s (see classic IBM’s VM/370) and thenint erest to hardware VMs became extinct. Basically, hardware VM is a thin layer ofsoftware called the virtual machine monitor (VMM). VMM manages executing VM code∗Copyright 2007 Denis Gudovskiy and Mattan Erez, all rights reserved. This work may be reproducedand redistributed, in whole or in part, without prior written permission, provided all copies cite theoriginal source of the document including the names of the copyright holders and ”The University ofTexas at Austin EE382V Spring 2007, Computer Architecture: User System Interplay”.2 EE382V: Lecture #5providing illusion of raw hardware execution. Nice thing abo ut hardware VMs is thatthey can execute any software. VMM at the same time must execute VMs with obeyinga safety. VMs have to work in isolation to protect own data and it is VMM’s job toarbiter all running VMs.Operating system–level virtualization concept is that VM layer lies between operatingsystem and actual applications. These a pplications could be VMs. So, VM interactswith operating system–level virtualization manager with direct a ccess to hardware.High-level language virtualization technique is just programming language (everyoneknows Java) that has means to provide abstraction layer. This virtualization layer residesinside program. Compiled code in this way can run o n every machine using abstractionlayer on top of the operating system.2.2 Why use virtual machine?In the general case, VMs allow to run several OSes on one computer or execute appli-cations complied on one machine on other machines with different hardware and OSes.Due to definition VMs must have several attributes:• Software compatibility and platform independence. Operating systems, applica-tions can run on other (host) operating system a nd various hardware platforms.• Isolation. VMs are isolated from host operating system and b etween each other.So, they can be potentially safer.• Encapsulation. VMs provide a level of indirection which can be used to control theexecution of the virtual machine. This extra control can be exploited to increasesafety and improve management.• Performance. VM inevitably adds performance overhead. Fortunately, differentoptimizations are possible in order to increase performance.3 Paper discuss ion3.1 What is the problem being solved?Briefly, paper solves following couple problems:• Software and hardware techniques for VMs.• Implicitly, paper app eals to SW a nd HW guys to discuss between each other whatwill be optimal to resolve VM problems e.g. what HW is lacking to handle VMs.Why did VMware explore hardware/hybrid VMs instead of just improving softwareones that they successfully built and sold before? First of all, until recently processorsEE382V: Lecture #5 3didn’t have good enough hardware support for virtualization. Also, there are severalbenefits to use hardware VMMs that likely will reincarnate hardware VMMs in futurecommercial products. Of course, hardware VMs performance potentially could be betterthan software ones because of natively less overheads. Secondly, compatibility issues onsoftware VMs. Imagine how many operating systems are used today with permanentupdates and how many will appear soon. Because of various operating systems it ishard to rewrite and verify software VMs to keep isolation and high performance everytime instead of just use thin standardized VMM. Hence, paper compares software andhardwar e techniques for VMs as well as discusses what hardwa re is lacking in order tobuild strong VM.3.2 Who are the intended users?Intended users of VMs are just everyone who wants ”software and hardware indepen-dence”. It is great to reuse any software executing on any hardware. More specific usersare following:• Computer architects that design future microprocessors. Since one of the mainmessage of the paper was t o review hardware support for VMs, computer architectsmay find what software guys expect from hardware.• System programmers who are writing VMs to understand how OS is working andint eracting with VMs. Operating–system level VMs resides between OS and appli-cations. So, system programmers could find useful information of how OS interactwith VM.• Programmers/HW designers that want to evaluate their solutions on various SW/HWplatforms. Suppose you built something. Then, it is cheaper and faster to test yoursolution on various configurations using VMs rat her than have tens environments.• Data centers which are interested in VM technology in order to off er vario us


View Full Document

UT EE 382V - A comparison of software and hardware techniques for x86 virtualization

Documents in this Course
Load more
Download A comparison of software and hardware techniques for x86 virtualization
Our administrator received your request to download this document. We will send you the file to your email shortly.
Loading Unlocking...
Login

Join to view A comparison of software and hardware techniques for x86 virtualization and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view A comparison of software and hardware techniques for x86 virtualization 2 2 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?