1 / 62

设备 虚拟化

设备 虚拟化. 汪小林 网络与信息技术研究所 北京大学信息学院. 主要内容. 设备虚拟化分类 直接访问（ Direct Access ） 模拟（ Emulated ） 半虚拟化（ Para-virtualized ） 存储虚拟化（ Storage Virtualization ） 写时复制硬盘（ Copy-on-Write Disks ）. 计算机系统组成. CPU. Memory. MMU. Controller. Local Bus. Interface. High-Speed I/O Bus. Frame Buffer. NIC.

makara
Download Presentation

设备 虚拟化

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. 设备虚拟化 汪小林 网络与信息技术研究所 北京大学信息学院

  2. 主要内容 • 设备虚拟化分类 • 直接访问（Direct Access） • 模拟（Emulated） • 半虚拟化（Para-virtualized） • 存储虚拟化（Storage Virtualization） • 写时复制硬盘（Copy-on-Write Disks）

  3. 计算机系统组成 CPU Memory MMU Controller Local Bus Interface High-Speed I/O Bus Frame Buffer NIC Controller Bridge LAN Low-Speed I/O Bus CD-ROM USB

  4. Device Virtualization • Goals • Isolation • Multiplexing • Speed • Mobility • Interposition • Device Virtualization Strategies • Direct Access • Emulation • Para-virtualization

  5. Direct Access Device VM Guest OS CPU Memory MMU Controller Local Bus Interface High-Speed I/O Bus Frame Buffer NIC Controller Bridge LAN Low-Speed I/O Bus CD-ROM USB

  6. Memory Isolation w/ Direct Access Device VM Guest OS CPU Memory MMU Controller Local Bus Interface IOMMU High-Speed I/O Bus Frame Buffer NIC Controller Bridge LAN Low-Speed I/O Bus CD-ROM USB

  7. Virtualization Enabled Device VM2 Guest OS VM1 Guest OS CPU Memory MMU Controller Local Bus Interface IOMMU High-Speed I/O Bus vNIC 2 vNIC 1 Frame Buffer NIC Controller Bridge LAN Low-Speed I/O Bus CD-ROM USB

  8. Direct Access Device Virtualization • Allow Guest OS direct access to underlying device • Positives • Fast • Simplify monitor • Limited device drivers needed • Negatives • Need hardware support for safety (IOMMU) • Need hardware support for multiplexing • Hardware interface visible to guest • Limits mobility of VM • Interposition hard by definition

  9. Emulated Devices • Emulate a device in class • Emulated registers • Memory mapped I/O or programmed I/O • Convert • Intermediate representation • Back-ends per real device

  10. Emulated Devices • Positives • Platform stability • Allows interposition • No special hardware support needed • Isolation, multiplexing implemented by monitor • Negatives • Can be slow • Drivers needed in monitor or host

  11. Para-Virtualized Devices • Guest passes requests to Monitor at a higher abstraction level • Monitor calls made to initiate requests • Buffers shared between guest / monitor • Positives • Simplify monitor • Fast • Negatives • Monitor needs to supply guest-specific drivers • Bootstrapping issues

More Related