Hardware Virtualization
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Effective Virtual CPU Configuration with QEMU and Libvirt
Effective Virtual CPU Configuration with QEMU and libvirt Kashyap Chamarthy <[email protected]> Open Source Summit Edinburgh, 2018 1 / 38 Timeline of recent CPU flaws, 2018 (a) Jan 03 • Spectre v1: Bounds Check Bypass Jan 03 • Spectre v2: Branch Target Injection Jan 03 • Meltdown: Rogue Data Cache Load May 21 • Spectre-NG: Speculative Store Bypass Jun 21 • TLBleed: Side-channel attack over shared TLBs 2 / 38 Timeline of recent CPU flaws, 2018 (b) Jun 29 • NetSpectre: Side-channel attack over local network Jul 10 • Spectre-NG: Bounds Check Bypass Store Aug 14 • L1TF: "L1 Terminal Fault" ... • ? 3 / 38 Related talks in the ‘References’ section Out of scope: Internals of various side-channel attacks How to exploit Meltdown & Spectre variants Details of performance implications What this talk is not about 4 / 38 Related talks in the ‘References’ section What this talk is not about Out of scope: Internals of various side-channel attacks How to exploit Meltdown & Spectre variants Details of performance implications 4 / 38 What this talk is not about Out of scope: Internals of various side-channel attacks How to exploit Meltdown & Spectre variants Details of performance implications Related talks in the ‘References’ section 4 / 38 OpenStack, et al. libguestfs Virt Driver (guestfish) libvirtd QMP QMP QEMU QEMU VM1 VM2 Custom Disk1 Disk2 Appliance ioctl() KVM-based virtualization components Linux with KVM 5 / 38 OpenStack, et al. libguestfs Virt Driver (guestfish) libvirtd QMP QMP Custom Appliance KVM-based virtualization components QEMU QEMU VM1 VM2 Disk1 Disk2 ioctl() Linux with KVM 5 / 38 OpenStack, et al. libguestfs Virt Driver (guestfish) Custom Appliance KVM-based virtualization components libvirtd QMP QMP QEMU QEMU VM1 VM2 Disk1 Disk2 ioctl() Linux with KVM 5 / 38 libguestfs (guestfish) Custom Appliance KVM-based virtualization components OpenStack, et al. -
QEMU Parameter Jungle Slides
Finding your way through the QEMU parameter jungle 2018-02-04 Thomas Huth <[email protected]> Legal ● Disclaimer: Opinions are my own and not necessarily the views of my employer ● “Jungle Leaves” background license: CC BY 3.0 US : https://creativecommons.org/licenses/by/3.0/us/ Image has been modified from the original at: https://www.freevector.com/jungle-leaves-vector-background 2 Introduction 3 Why a guide through the QEMU parameter jungle? 4 Why a guide through the QEMU parameter jungle? ● QEMU is a big project, supports lots of emulated devices, and lots of host backends ● 15 years of development → a lot of legacy ● $ qemu-system-i386 -h | wc -l 454 ● People regularly ask about CLI problems on mailing lists or in the IRC channels → Use libvirt, virt-manager, etc. if you just want an easier way to run a VM 5 General Know-How ● QEMU does not distinguish single-dash options from double-dash options: -h = --h = -help = --help ● QEMU starts with a set of default devices, e.g. a NIC and a VGA card. If you don't want this: --nodefaults or suppress certain default devices: --vga none --net none 6 Getting help about the options ● Parameter overview: -h or --help (of course) ● Many parameters provide info with “help”: --accel help ● Especially, use this to list available devices: --device help ● To list parameters of a device: --device e1000,help ● To list parameters of a machine: --machine q35,help 7 e1000 example ● $ qemu-system-x86_64 --device e1000,help [...] e1000.addr=int32 (PCI slot and function¼) e1000.x-pcie-extcap-init=bool (on/off) e1000.extra_mac_registers=bool (on/off) e1000.mac=str (Ethernet 6-byte MAC Address¼) e1000.netdev=str (ID of a netdev backend) ● $ qemu-system-x86_64 --device \ e1000,mac=52:54:00:12:34:56,addr=06.0 8 General Know How: Guest and Host There are always two parts of an emulated device: ● Emulated guest hardware, e.g.: --device e1000 ● The backend in the host, e.g.: --netdev tap Make sure to use right set of parameters for configuration! 9 “Classes” of QEMU parameters ● Convenience : Easy to use, but often limited scope. -
VM Virtualization Tasks Problems of X86 Categories of X86 Virtualization
VM Starts from IBM VM/370 definition: "an efficient, isolated duplicate of a real machine" Old purpose: share the resource of the expensive mainframe machine New purpose: fault tolerance and security; run multiple different OSes on the same desktop; server consolidation and performance isolation, etc. type 1 vmm: vmm running on bare hardware type 2 vmm: vmm running on host os Virtualization tasks (isolate, secure, fast, transparent …) 1. cpu virtualization How to make sure privileged instructions (e.g., enable/disable interrupts; change critical registers) will not be executed directly 2. memory virtualization OS thought they can control the whole physical memory. No! 3. I/O virtualization OS thought I/O devices are all under its own control. No! Problems of X86 1. Some privileged instructions do not trap; they just fail/change-semantic silently. 2. TLB miss will be handled by hardware instead of software Categories of X86 virtualization Full-virtualization (VMWare) No change to guest OS Use binary translation to change some instructions (privilege instructions or all OS code) on the fly Para-virtualization (Xen) Change guest OS to improve performance Rewrite OS; replace privileged instructions with hypercalls Many other changes Disco On MIPS DISCO directly runs on multi-processor machine; Oses run upon DISCO Goal: use commodity OSes to leverage many-core cluster VMM runs in kernel mode VM OS runs in supervisor mode VM user runs in user mode Privileged instructions will trap to VMM and be emulated CPU virtualization No special challenge (seemed that all privilege instructions will trap) VMM maintains a process-table-entry-like data structure for each VM (virtual PC) (including registers, states, and TLB content (used for emulation …) ). -
Many Things Related to Qubesos
Qubes OS Many things Many things related to QubesOS Author: Neowutran Contents 1 Wiping VM 2 1.1 Low level storage technologies .................. 2 1.1.1 Must read ......................... 2 1.1.2 TL;DR of my understanding of the issue ........ 2 1.1.3 Things that could by implemented by QubesOS .... 2 2 Create a Gaming HVM 2 2.1 References ............................. 2 2.2 Prerequise ............................. 3 2.3 Hardware ............................. 3 2.4 Checklist .............................. 4 2.5 IOMMU Group .......................... 4 2.6 GRUB modification ........................ 4 2.7 Patching stubdom-linux-rootfs.gz ................ 5 2.8 Pass the GPU ........................... 6 2.9 Conclusion ............................. 6 2.10 Bugs ................................ 6 3 Create a Linux Gaming HVM, integrated with QubesOS 7 3.1 Goals ................................ 7 3.2 Hardware used .......................... 7 3.3 Main steps summary ....................... 7 3.3.1 Detailled steps ...................... 8 3.3.2 Using a kernel provided by debian ............ 8 3.4 Xorg ................................ 8 3.4.1 Pulseaudio ......................... 11 3.5 Final notes ............................ 11 3.6 References ............................. 12 4 Nitrokey and QubeOS 12 5 Recovery: Mount disk 12 6 Disposable VM 13 6.1 Introduction ............................ 14 6.1.1 References ......................... 14 6.1.2 What is a disposable VM? ................ 14 6.2 Playing online video ....................... 14 6.3 Web browsing ........................... 15 6.4 Manipulating untrusted files/data ................ 16 1 6.5 Mounting LVM image ...................... 17 6.6 Replace sys-* VM ......................... 18 6.7 Replace some AppVMs ...................... 18 7 Building a new QubesOS package 18 7.1 References ............................. 18 7.2 Goal ................................ 18 7.3 The software ............................ 19 7.4 Packaging ............................. 19 7.5 Building ............................. -
Security Analysis of Encrypted Virtual Machines
Security Analysis of Encrypted Virtual Machines Felicitas Hetzelt Robert Buhren Technical University of Berlin Technical University of Berlin Berlin, Germany Berlin, Germany fi[email protected] [email protected] Abstract 1. Introduction Cloud computing has become indispensable in today’s com- Cloud computing has been one of the most prevalent trends puter landscape. The flexibility it offers for customers as in the computer industry in the last decade. It offers clear ad- well as for providers has become a crucial factor for large vantages for both customers and providers. Customers can parts of the computer industry. Virtualization is the key tech- easily deploy multiple servers and dynamically allocate re- nology that allows for sharing of hardware resources among sources according to their immediate needs. Providers can different customers. The controlling software component, ver-commit their hardware and thus increase the overall uti- called hypervisor, provides a virtualized view of the com- lization of their systems. The key technology that made this puter resources and ensures separation of different guest vir- possible is virtualization, it allows multiple operating sys- tual machines. However, this important cornerstone of cloud tems to share hardware resources. The hypervisor is respon- computing is not necessarily trustworthy or bug-free. To mit- sible for providing temporal and spatial separation of the igate this threat AMD introduced Secure Encrypted Virtu- virtual machines (VMs). However, besides these advantages alization, short SEV, which transparently encrypts a virtual virtualization also introduced new risks. machines memory. Customers who want to utilize the infrastructure of a In this paper we analyse to what extend the proposed fea- cloud provider must fully trust the cloud provider. -
QEMU for Xen Secure by Default
QEMU for Xen secure by default Deprivileging the PC system emulator Ian Jackson <[email protected]> FOSDEM 2016 with assistance from Stefano Stabellini guest guest Xen PV driver IDE driver Xen PV protocol mmio, dma, etc. qemu Emulated IDE controller Xen PV backend (usually), syscalls (usually) dom0 (usu.dom0) kernel Device driver kernel Device driver PV HVM ... ... ... ... ... from Xen Security Team advisories page, http://xenbits.xen.org/xsa/ Xen on x86 modes, and device model bug implications Current status for users of upstream Xen and distros and future plans Status Device model Notes bugs mean PV Fully supported Safe (no DM) Only modified guests HVM qemu in dom0 Fully supported Vulnerable Current default as root HVM qemu stub DM Upstream but not Safe Ancient qemu qemu-xen-trad. in most distros. Build system problems HVM qemu stub DM In progress Safe Rump build system rump kernel Hard work! is mini distro HVM qemu dom0 Targeting No privilege esc. Defence in depth not as root Xen 4.7 Maybe dom0 DoS Hopefully, will be default Xen on x86 modes, and device model bug implications Current status for users of upstream Xen and distros and future plans Status Device model Notes bugs mean PV Fully supported Safe (no DM) Only modified guests HVM qemu in dom0 Fully supported Vulnerable Current default as root HVM qemu stub DM Upstream but not Safe Ancient qemu qemu-xen-trad. in most distros. Build system problems HVM qemu stub DM In progress Safe Rump build system rump kernel Hard work! is mini distro HVM qemu dom0 Targeting No privilege esc. -
Hyperlink: Virtual Machine Introspection and Memory Forensic Analysis Without Kernel Source Code Jidong Xiao Boise State University
Boise State University ScholarWorks Computer Science Faculty Publications and Department of Computer Science Presentations 1-1-2016 HyperLink: Virtual Machine Introspection and Memory Forensic Analysis without Kernel Source Code Jidong Xiao Boise State University Lei Lu VMware Inc. Haining Wang University of Delaware Xiaoyun Zhu Futurewei Technologies © 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. doi: 10.1109/ICAC.2016.46 HyperLink: Virtual Machine Introspection and Memory Forensic Analysis without Kernel Source Code Jidong Xiao∗, Lei Luy, Haining Wangz, Xiaoyun Zhux ∗Boise State University, Boise, Idaho, USA yVMware Inc., Palo Alto, California, USA zUniversity of Delaware, Newark, Delaware, USA xFuturewei Technologies, Santa Clara, California, USA Abstract— Virtual Machine Introspection (VMI) is an ap- nel rootkit detection [8], [9], kernel integrity protection [10], proach to inspecting and analyzing the software running inside a and detection of covertly executing binaries [11]. Being the virtual machine from the hypervisor. Similarly, memory forensics main enabling technology for cloud computing, virtualiza- analyzes the memory snapshots or dumps to understand the tion allows us allocating finite hardware resources among runtime state of a physical or virtual machine. The existing VMI a large number of software systems and programs. As the and memory forensic tools rely on up-to-date kernel information key component of virtualization, a hypervisor runs directly of the target operating system (OS) to work properly, which often requires the availability of the kernel source code. -
Protection Strategies for Direct Access to Virtualized I/O Devices
Protection Strategies for Direct Access to Virtualized I/O Devices Paul Willmann, Scott Rixner, and Alan L. Cox Rice University {willmann, rixner, alc}@rice.edu Abstract chine virtualization [1, 2, 5, 8, 9, 10, 14, 19, 22]. How- Commodity virtual machine monitors forbid direct ac- ever, virtualization can impose performance penalties up cess to I/O devices by untrusted guest operating systems to a factor of 5 on I/O-intensive workloads [16, 19]. in order to provide protection and sharing. However, These penalties stem from the overhead of providing both I/O memory management units (IOMMUs) and re- shared and protected access to I/O devices by untrusted cently proposed software-based methods can be used to guest operating systems. Commodity virtualization ar- reduce the overhead of I/O virtualization by providing chitectures provide protection in software by forbidding untrusted guest operating systems with safe, direct ac- direct access to I/O hardware by untrusted guests— cess to I/O devices. This paper explores the performance instead, all I/O accesses, both commands and data, are and safety tradeoffs of strategies for using these mecha- routed through a single software entity that provides both nisms. protection and sharing. The protection strategies presented in this paper pro- Preferably, guest operating systems would be able to vide equivalent inter-guest protection among operating directly access I/O devices without the need for the data system instances. However, they provide varying levels to traverse an intermediate software layer within the vir- of intra-guest protection from driver software and incur tual machine monitor [17, 23]. -
Virtualization
Virtualization ...or how adding another layer of abstraction is changing the world. CIS 399: Unix Skills University of Pennsylvania April 6, 2009 (CIS 399 Unix) Virtualization April 6, 2009 1 / 22 What is virtualization? Without virtualization: (CIS 399 Unix) Virtualization April 6, 2009 2 / 22 What is virtualization? With virtualization: (CIS 399 Unix) Virtualization April 6, 2009 3 / 22 Why virtualize? (CIS 399 Unix) Virtualization April 6, 2009 4 / 22 Why virtualize? Operating system independence Hardware independence Resource utilization Security Flexibility (CIS 399 Unix) Virtualization April 6, 2009 5 / 22 Virtualization for Users Parallels Desktop and VMware Fusion have brought virtualization to normal computer users. Mostly used for running Windows programs side-by-side with OS X programs. Desktop use has pushed support for: I USB devices I Better graphics performance (3d acceleration) I Integration between the guest and host operating system and applications. (CIS 399 Unix) Virtualization April 6, 2009 6 / 22 Virtualization for Developers Build and test on multiple operating systems with a single computer. Use VM snapshots to provide a consistent testing environment. Run the debugger from outside the virtual machine. I Isolates the debugger and program from each other. I Allows easy kernel debugging. I Snapshotting and record/replay allow you to capture and analyze rare bugs. (CIS 399 Unix) Virtualization April 6, 2009 7 / 22 Virtualization for Business Hardware independence - upgrade hardware without reinstalling software. Resource utilization - turn 10 hosts with 10% utilization into 1 host with 100% utilization. Big power and cooling savings! Migration - move a server to a different machine without shutting it down. -
Bringing Virtualization to the X86 Architecture with the Original Vmware Workstation
12 Bringing Virtualization to the x86 Architecture with the Original VMware Workstation EDOUARD BUGNION, Stanford University SCOTT DEVINE, VMware Inc. MENDEL ROSENBLUM, Stanford University JEREMY SUGERMAN, Talaria Technologies, Inc. EDWARD Y. WANG, Cumulus Networks, Inc. This article describes the historical context, technical challenges, and main implementation techniques used by VMware Workstation to bring virtualization to the x86 architecture in 1999. Although virtual machine monitors (VMMs) had been around for decades, they were traditionally designed as part of monolithic, single-vendor architectures with explicit support for virtualization. In contrast, the x86 architecture lacked virtualization support, and the industry around it had disaggregated into an ecosystem, with different ven- dors controlling the computers, CPUs, peripherals, operating systems, and applications, none of them asking for virtualization. We chose to build our solution independently of these vendors. As a result, VMware Workstation had to deal with new challenges associated with (i) the lack of virtual- ization support in the x86 architecture, (ii) the daunting complexity of the architecture itself, (iii) the need to support a broad combination of peripherals, and (iv) the need to offer a simple user experience within existing environments. These new challenges led us to a novel combination of well-known virtualization techniques, techniques from other domains, and new techniques. VMware Workstation combined a hosted architecture with a VMM. The hosted architecture enabled a simple user experience and offered broad hardware compatibility. Rather than exposing I/O diversity to the virtual machines, VMware Workstation also relied on software emulation of I/O devices. The VMM combined a trap-and-emulate direct execution engine with a system-level dynamic binary translator to ef- ficiently virtualize the x86 architecture and support most commodity operating systems. -
Virtualization of Linux Based Computers: the Linux-Vserver Project
VirtualizationVirtualization ofof LinuxLinux basedbased computers:computers: thethe LinuxLinux--VServerVServer projectproject BenoBenoîîtt desdes Ligneris,Ligneris, Ph.Ph. D.D. [email protected] Objectives:Objectives: Objectives:Objectives: 1)1) PresentPresent thethe availableavailable programsprograms thatthat cancan provideprovide aa virtualizationvirtualization ofof LinuxLinux computerscomputers withwith differentdifferent technologies.technologies. Objectives:Objectives: 1)1) PresentPresent thethe availableavailable programsprograms thatthat cancan provideprovide aa virtualizationvirtualization ofof LinuxLinux computerscomputers withwith differentdifferent technologies.technologies. 2)2) FocusFocus onon LinuxLinux--VServers:VServers: aa veryvery lightweightlightweight andand effectiveeffective technologytechnology forfor thethe regularregular LinuxLinux useruser notnot interstedintersted inin KernelKernel hacking.hacking. PlanPlan PlanPlan ● IntroductionIntroduction PlanPlan ● IntroductionIntroduction ● OverviewOverview ofof thethe availableavailable technologytechnology PlanPlan ● IntroductionIntroduction ● OverviewOverview ofof thethe availableavailable technologytechnology ● ClassificationClassification ofof thethe problems:problems: usageusage criteriacriteria PlanPlan ● IntroductionIntroduction ● OverviewOverview ofof thethe availableavailable technologytechnology ● ClassificationClassification ofof thethe problems:problems: usageusage criteriacriteria ● ComparativeComparative studystudy ofof thethe existingexisting -
Draft NISTIR 8221
Withdrawn Draft Warning Notice The attached draft document has been withdrawn, and is provided solely for historical purposes. It has been superseded by the document identified below. Withdrawal Date June 5, 2019 Original Release Date September 21, 2018 Superseding Document Status Final Series/Number NISTIR 8221 Title A Methodology for Enabling Forensic Analysis Using Hypervisor Vulnerabilities Data Publication Date June 2019 DOI https://doi.org/10.6028/NIST.IR.8221 CSRC URL https://csrc.nist.gov/publications/detail/nistir/8221/final Additional Information 1 Draft NISTIR 8221 2 3 A Methodology for Determining 4 Forensic Data Requirements for 5 Detecting Hypervisor Attacks 6 7 8 Ramaswamy Chandramouli 9 Anoop Singhal 10 Duminda Wijesekera 11 Changwei Liu 12 13 14 Draft NISTIR 8221 15 16 A Methodology for Determining 17 Forensic Data Requirements for 18 Detecting Hypervisor Attacks 19 20 Ramaswamy Chandramouli 21 Anoop Singhal 22 Duminda Wijesekera 23 Changwei Liu 24 Computer Security Division 25 Information Technology Laboratory 26 27 28 29 30 31 32 33 34 35 36 September 2018 37 38 39 40 41 U.S. Department of Commerce 42 Wilbur L. Ross, Jr., Secretary 43 44 National Institute of Standards and Technology 45 Walter Copan, NIST Director and Under Secretary of Commerce for Standards and Technology 46 47 National Institute of Standards and Technology Internal Report 8221 48 27 pages (September 2018) 49 50 51 Certain commercial entities, equipment, or materials may be identified in this document in order to describe an 52 experimental procedure or concept adequately. Such identification is not intended to imply recommendation or 53 endorsement by NIST, nor is it intended to imply that the entities, materials, or equipment are necessarily the best 54 available for the purpose.