虚拟计算技术研究概述 - 清华大学计算机系高性能所.ppt
《虚拟计算技术研究概述 - 清华大学计算机系高性能所.ppt》由会员分享,可在线阅读,更多相关《虚拟计算技术研究概述 - 清华大学计算机系高性能所.ppt(71页珍藏版)》请在温州文客信息科技有限公司上搜索。
1、Introduction to Virtualization,Kang ChenHPC, DCST, Tsinghua,Outlines,Virtualization is HOT!,History,History,What is virtualization?,See multiple OSes?,Terminology,Virtualization: What is it?,Motivations,Virtual Machine Monitor,Software Layer between hardware and OS, virtualizes and manage hardware r
2、esources,Virtualization Levels,HARDWARE,KERNEL,USER LEVEL LIBRARIES,APPLICATIONS,API Calls,System Calls,Instructions,User Space,Kernel Space,Levels of Virtualization,ISA Level Virtualization,ISA Level Virtualization:Examples,Stanford DISCO,Emulator , Binary Translation,CPU EmulatorSimulate different
3、 ISA while running on one ISA machine, E.g. Intel IA32 emulator running on MAC based on PowerPCBinary TranslationTranslate the code from one ISA to anotherE.g. translate the application code from IA32 to IPF,Other Emulators,Virtutech Simics, Simics models dozens of processor types and associated per
4、ipheral devices, including systems based on Alpha, PowerPC, SPARC, IA32 (x86), and x86-64 “Hammer” CPUs, as well as IA-64 (Itanium), ARM and MIPSMicrosoft Virtual PC for MACSun Shade: emulate the ISA of SPARC and MIPS I,Binary Translation,FX!32: Run x86 windows NT programs on top of Windows for Alph
5、aIA32 EL: The IA32 Execution Layer. Run x86 programs on top of Windows for IPFDynamo System: Improving the performances by using binary translation, both on HP PA8000Aries System: Run programs written for PA-RISC on top of IPF,HAL Level Virtualization,Stand Alone vs. Hosted,21,Hardware,Hardware,Hard
6、ware,Host OS,VMM,Guest OS2,Guest OS1,App,App,Host OS,VMM,Guest OS1,App,Guest OS2,App,JVMCLRVMware Workstation,Microsoft Virtual Server,VMM,Guest OS2,Guest OS1,App,App,VMware ESX ServerXenMS Viridian,Vmware Workstation Architecture,Guest OS Applications,Guest Operating System,Host OS Apps,Host OS,Dis
7、ks,Memory CPU,NIC,VMware App,Virtual Machine,VMware Driver,Virtual Machine Monitor,PC Hardware,World Switch: save and restore all the hardware states (Host OS and VMM share the same highest privilege.,Vmware ESX Server,Memory,nic,nic,NIC,disk,x86 SMPHardware,ConsoleOS,VMM,GuestOS,GuestOS,GuestOS,Gue
8、stOS,VMkernel,VMM,VMM,VMM,VMware I/O Virtualization,VMM does not have access to I/OI/O in “host world”Low level I/O instructions (issued by guest OS) are merged to high-level I/O system callsVM Application executes I/O SysCallsVM Driver works as the communication link between VMM and VM Application,
9、Virtual PC,“Everything is about Microsoft”,Paravirtualization,VMware / Virtual PCGuest OS lives in a complete virtual world with no knowledge about the real machineSupport legacy OSDifficult to scale to high numbersInterrupt handling/memory management/world switchingSolution?ParavirtualizationProvid
10、es a much simpler architecture interface for the customized guest OSesVirtual I/O and CPU instructions, registers, Trade portability for performance and scalabilityDenali/Xen,Xen,Exposes some “real” hardwareE.g. clock, physical memory addressMaintain the same application binary interface(ABI)The eff
11、ort of porting OSes is minimalExamples:Page tableGuest OS have the direct access to hardware page tables, but updates are batched and validated by XenTimer InterfaceGuest Os is aware both “real” and “virtual” time,Xen Architecture,Hardware,Xen,Domain0,XenoLinux,XenoWindows,Application,Application,Ap
12、plication,Application,Application,Application,Application,Application,Application,Control, I/O(Domain 0),Guest Domain,Guest Domain,Application,Denali,Design to support thousands of VM instance running network servicesHosting a single application, single-user unprotected guest OSNot support ABI compa
13、tibilityNot support virtual memory,Pre- Virtualization,Others,User-mode Linux: run Linux on top of LinuxVirtual device: port Linux kernel to the Linux system call interface rather than a hardware interfaceUsing ptrace facility to track system calls and trap them into user-space kernelCooperative Lin
14、ux: run Linux as an unprivileged VM in kernel mode on top of another OS, e.t., WindowsHost OS needs to support loading driversEach kernel has its own complete CPU context and address space, and decide when to give the control back to its parterner,ExoKernel,Traditional centralized resource managemen
15、t cannot be specialized, extended or replacedPrivileged software must be used by all applicationsFixed high level abstractions too costly for good efficiencyProvide low level interface for library operating systems (libOSes) to use in claiming, using and releasing machine resourcesSeparate protectio
16、n from management using secure bindings, visible revocation and an abort protocol,Hardware Support for HAL Virtualization,Intel Virtualization TechnologyVT-x,VT-i, VT-dCPU virtualizationMemory virtualizationI/O virtualizationAMDSecure Virtual Machine,Software Challenge, Running VMM Code,Physical Hos
17、t Hardware,VM1,VM Monitor,VM0,Guest OS0,App,App,App,.,.,Guest OS1,App,App,App,.,OS and APPs in a VM dont know that the VMM exists and will hog the CPU,VMM should run “protected” from Guest SW,SW Solution: Guest OS Ring Deprivileging,Physical Host Hardware,VM1,VM Monitor,VM0,Guest OS0,App,App,App,.,.
18、,Guest OS1,App,App,App,.,Run Guest OS above Ring-0 and have privileged instructions generate faults.,Run VMM in Ring-0 as a collection of fault handlers,Non-trivial Problems: Ring CompressionNon-trapping InstructionsExcessive FaultingAddr Space Compression ,Guest OS de-privileging requires complex u
19、northodox methods,Non-trivial Solutions: Source guest OS Modifications: Paravirtualization Legacy OSes not supported Binary guest OS Mods: Dynamic patching/ Binary translation OS Service Pack VMM Service Pack,Intel Virtualization Technology,Physical Host Hardware,VM1,VM Monitor,VM0,Guest OS0,App,App
20、,App,.,.,Guest OS1,App,App,App,.,OSs and Apps run in the intended ring,VMM runs in a new operation mode VMM preempts guest execution via new programmatic transitions,VT HW support for Processor Virtualization New CPU execution mode HW-based mode transitions Memory protection in HW,By design, VT elim
21、inates both virtualization holes and the need for unorthodox software methods,VT-x Technology Overview,ring 3,ring 0,VMX Root,Virtual Machines (VMs),Apps,OS,VM Monitor (VMM),Apps,OS,VM Exit,VM Entry,VMCS,VMCS,VMX Non-Root,OS Level Virtualization,Containers (operating environments) on top of OSProces
22、ses, File System, Network resource (IP address), Environment variables, System call interfaceTechnologieschroot(): File system virtualization on Unix; change the root directory of a process and its childrenName spaces: Each container is tagged and new entities (fork() generated from a container rema
23、ins insideUsages:SandboxingFine grain access control (root in the container),chroot,Examples,JailFreeBSD based virtualization using “chroot()”Scope is limited to the jailCurtailed assess to resources and operationsA file-system sub-tree, one IP address, one “root”Ensims “Virtual Private Server”Linux
- 1.请仔细阅读文档,确保文档完整性,对于不预览、不比对内容而直接下载带来的问题本站不予受理。
- 2.下载的文档,不会出现我们的网址水印。
- 3、该文档所得收入(下载+内容+预览)归上传者、原创作者;如果您是本文档原作者,请点此认领!既往收益都归您。
下载文档到电脑,查找使用更方便
20 文钱
下载 | 加入VIP,畅享折扣下载 |
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- 虚拟 计算 技术研究 概述 清华大学 计算机系 性能
![提示](https://www.wenke99.com/images/bang_tan.gif)
链接地址:https://www.wenke99.com/p-224734.html