Xen 10th anniversary Status Report (at SELF 2013)
- 1. Russell Pavlicek Xen Project Evangelist Russell.Pavlicek@XenProject.org Xen Project 10th Anniversary Status @RCPavlicek Skype: russpavlicek
- 2. • Linux user since 1995; Linux desktop since 1997 • Linux advocate before I ever saw the software • Early advocate in DEC, Compaq • Former columnist for Infoworld, Processor • Former panelist on The Linux Show • Wrote book, Embracing Insanity: Open Source Software Development • Speaker at 40+ conferences • Currently Xen Project Evangelist employed by Citrix About the Speaker...
- 3. • Teams aka sub-projects – Hypervisor – XAPI – ARM Hypervisor (for Servers as well as Mobile Devices) – Mirage OS • Governance : mixture between Linux Kernel and Apache – Consensus decision making – Sub-project life-cycle (aka incubator) – PMC style structure for team leadership News: Xen.org becomes XenProject.org
- 4. Why Should I Care about Xen?
- 5. Xen is ready for business • Enterprise-worthy scalability • Solid track record (Amazon bets their AWS business on us) • Linux Foundation Project Partners: –AMD, Amazon, Cisco, Citrix, Intel, Oracle, Samsung, Verizon, and more
- 6. Xen contributor community is diversifying 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 2010 2011 2012 Citrix UPC SUSE Amazon University AMD GridCentric Individual NSA Intel Fujitsu iWeb Misc Oracle Spectralogic University of British Columbia • The number of “significant” active vendors is increasing • New feature development driving new participation
- 7. Xen has the technology • Top notch Hypervisor • Live Migration of VMs: XenMotion (in XCP) • Cloud-readiness: Xen Cloud Platform & XAPI • High Availability: Remus • Wide variety of Control Domains supported • Even wider variety of Guest Domains • Multiple virtualization modes improve performance
- 9. Hypervisor Architectures Type 1: Bare metal Hypervisor A pure Hypervisor that runs directly on the hardware and hosts Guest OS’s. Provides partition isolation + reliability, higher security Host HW Memory CPUsI/O HypervisorScheduler MMUDevice Drivers/Models VMn VM1 VM0 Guest OS and Apps
- 10. Hypervisor Architectures Type 1: Bare metal Hypervisor A pure Hypervisor that runs directly on the hardware and hosts Guest OS’s. Type 2: OS ‘Hosted’ A Hypervisor that runs within a Host OS and hosts Guest OS’s inside of it, using the host OS services to provide the virtual environment. Provides partition isolation + reliability, higher security Low cost, no additional drivers Ease of use & installation Host HW Memory CPUsI/O Host HW Memory CPUsI/O HypervisorScheduler MMUDevice Drivers/Models VMn VM1 VM0 Guest OS and Apps Host OS Device Drivers Ring-0 VM Monitor “Kernel “ VMn VM1 VM0 Guest OS and Apps User Apps User-level VMM Device Models
- 11. Xen: Type 1 with a Twist Type 1: Bare metal Hypervisor Host HW Memory CPUsI/O HypervisorScheduler MMUDevice Drivers/Models VMn VM1 VM0 Guest OS and Apps
- 12. Xen: Type 1 with a Twist Type 1: Bare metal Hypervisor Host HW Memory CPUsI/O HypervisorScheduler MMUDevice Drivers/Models VMn VM1 VM0 Guest OS and Apps Host HW Memory CPUsI/O Hypervisor VMn VM1 VM0 Guest OS and Apps Xen Architecture Scheduler MMU
- 13. Xen: Type 1 with a Twist Type 1: Bare metal Hypervisor Host HW Memory CPUsI/O HypervisorScheduler MMUDevice Drivers/Models VMn VM1 VM0 Guest OS and Apps Host HW Memory CPUsI/O Hypervisor VMn VM1 VM0 Guest OS and Apps Xen Architecture Scheduler MMU Control domain (dom0) Drivers Device Models Linux & BSD
- 14. Xen Project and Linux • Xen Hypervisor is not in the Linux kernel • BUT: everything Xen and Xen Guests need to run is! • Xen packages are in all Linux distros (except RHEL6) – Install Control Domain (Dom0) Linux distribution – Install Xen package(s) or meta package – Reboot – Configure stuff: set up disks, peripherals, etc. More info: wiki.xenproject.org/wiki/Category:Host_Install
- 15. Basic Xen Concepts 15 Control domain (dom0) Host HW VMn VM1 VM0 Guest OS and Apps Memory CPUsI/O Console • Interface to the outside world Control Domain aka Dom0 • Dom0 kernel with drivers • Xen Management Toolstack Guest Domains • Your apps Driver/Stub/Service Domain(s) • A “driver, device model or control service in a box” • De-privileged and isolated • Lifetime: start, stop, kill Dom0 Kernel HypervisorScheduler MMU XSM Trusted Computing Base
- 16. Basic Xen Concepts 16 Control domain (dom0) Host HW VMn VM1 VM0 Guest OS and Apps Console Memory CPUsI/O Dom0 Kernel Toolstack HypervisorScheduler MMU XSM Console • Interface to the outside world Control Domain aka Dom0 • Dom0 kernel with drivers • Xen Management Toolstack Guest Domains • Your apps Driver/Stub/Service Domain(s) • A “driver, device model or control service in a box” • De-privileged and isolated • Lifetime: start, stop, kill Trusted Computing Base
- 17. Basic Xen Concepts 17 Control domain (dom0) Host HW VMn VM1 VM0 Guest OS and Apps Console Memory CPUsI/O One or more driver, stub or service domains Dom0 Kernel Toolstack HypervisorScheduler MMU XSM Console • Interface to the outside world Control Domain aka Dom0 • Dom0 kernel with drivers • Xen Management Toolstack Guest Domains • Your apps Driver/Stub/Service Domain(s) • A “driver, device model or control service in a box” • De-privileged and isolated • Lifetime: start, stop, kill Trusted Computing Base
- 18. 18 Xen Variants for Server & Cloud Xen HypervisorHypervisor
- 19. Single Host Basic Functions Multiple Hosts Additional Functionality 19 Xen Variants for Server & Cloud Increased level of functionality and integration with other components Default / XL (XM)Toolstack / Console Libvirt / VIRSH XAPI / XE Hypervisor Single Host Additional Functionality Xen Hypervisor
- 20. Single Host Basic Functions Multiple Hosts Additional Functionality Xen Variants for Server & Cloud Increased level of functionality and integration with other components Default / XL (XM)Toolstack / Console Libvirt / VIRSH XAPI / XE Hypervisor Single Host Additional Functionality Xen Hypervisor
- 21. 21 Xen Variants for Server & Cloud Increased level of functionality and integration with other components Default / XL (XM)Toolstack / Console Libvirt / VIRSH Products Oracle VM Huawei UVP Citrix XenServer Project XAPI / XE Xen Hypervisor
- 22. 22 Xen Variants for Server & Cloud Increased level of functionality and integration with other components Default / XL (XM)Toolstack / Console Libvirt / VIRSH Used by … Project XAPI / XE Products Oracle VM Huawei UVP Citrix XenServer Xen Hypervisor
- 23. Xen : Types of Virtualization
- 24. Xen Virtualization Vocabulary • PV – Paravirtualization – Hypervisor provides API used by the OS of the Guest VM – Guest OS needs to be modified to provide the API • HVM – Hardware-assisted Virtual Machine – Uses CPU VM extensions to handle Guest requests – No modification to Guest OS – But CPU must provide VM extensions • FV – Full Virtualization (another name for HVM)
- 25. Xen Virtualization Vocabulary • PVHVM – PV on HVM drivers – Allows H/W virtualized guests to use PV disk and I/O drivers – No modifications to guest OS – Better performance than straight HVM • PVH – PV in HVM Container (coming in 4.4) – Almost fully PV – Uses HW extensions to eliminate PV MMU – Possibly best mode for CPUs with virtual H/W extensions
- 26. 26 Xen Hypervisor Control domain (dom0) Host HW Guest VMn Apps Memory CPUsI/O Technology: • Paravirtualization Linux PV guests have limitations: • Limited to a subset of set of virtual H/W Advantages • Fast • Works on any system (even without CPU virtual extensions) HW Drivers PV Back Ends PV Front Ends Guest OSDom0 Kernel Paravirtualization (PV) Domains
- 27. 27 Xen Hypervisor Control domain (dom0) Host HW Guest VMn Apps Memory CPUsI/O Technology: • Paravirtualization Linux PV guests have limitations: • Limited to a subset of virtual H/W Advantages • Fast • Works on any system (even without CPU virtual extensions) Driver Domains (Disaggregation) • Security • Isolation • Reliability and Robustness HW Drivers PV Back Ends PV Front Ends Driver Domain e.g. • Disk • Network HW Driver PV Back End Dom0 Kernel* *) Can be MiniOS Guest OSDom0 Kernel PV Domains & Driver Domains
- 28. 28 Xen Hypervisor Dom0 Host HW Guest VMn Technology: • Shows emulation using QEMU/Device Model (SW Virtualization) • In other situation H/W can be used Disadvantages • Emulation slower than PV (mainly I/O devices) Advantages • No kernel support needed Device Model IO Emulation IO Event VMEXITDom0 Kernel H/W Virtual Machine (HVM) & Stub Domains Memory CPUsI/O
- 29. 29 Xen Hypervisor Dom0 Host HW Guest VMn Technology: • Shows emulation using QEMU/Device Model (SW Virtualization) • In other situation H/W can be used Disadvantages • Emulation slower than PV (mainly I/O devices) Advantages • No kernel support needed Stub Domains • Security • Isolation • Reliability and Robustness Device Model IO Emulation IO Event VMEXIT Stubdomn Device Model Mini OS Guest VMn IO Emulation IO Event VMEXITDom0 Kernel H/W Virtual Machine (HVM) & Stub Domains Memory CPUsI/O
- 30. The Virtualization Spectrum Fully Virtualized (FV) VS VS VS VH FV with PV for disk & network P VS VS VH PVHVM P P VS VH PVH P P P VH Fully Paravirtualized (PV) P P P P VH Virtualized (HW) P Paravirtualized VS Virtualized (SW) HVM mode/domain PV mode/domain Xen 4.4
- 31. The Virtualization Spectrum Fully Virtualized (FV) VS VS VS VH FV with PV for disk & network P VS VS VH PVHVM P P VS VH PVH P P P VH Fully Paravirtualized (PV) P P P P Scope for improvement Poor performance Optimal performance HVM mode/domain Xen 4.4 PV mode/domain
- 32. The Virtualization Spectrum Fully Virtualized (FV) VS VS VS VH FV with PV for disk & network P VS VS VH PVHVM P P VS VH PVH P P P VH Fully Paravirtualized (PV) P P P P Scope for improvement Poor performance Optimal performance HVM mode/domain Xen 4.4 PV mode/domain Important: Xen automatically picks the best option based on HW & OS capabilities and available drivers. As a Xen user I chose a HVM or PV domain.
- 33. XAPI, XCP and XCP-XAPI
- 34. Single Host Basic Functions Multiple Hosts Additional Functionality XAPI, XCP and XCP-XAPI : What is it? Increased level of functionality and integration with other components Default / XL (XM)Toolstack / Console Libvirt / VIRSH XAPI / XE Hypervisor Single Host Additional Functionality Xen Hypervisor
- 35. XAPI : What do I get? Multiple Hosts Additional Functionality XAPI / XE Xen Hypervisor • VM lifecycle: live snapshots, checkpoint, migration • Storage XenMotion: Migrate VMs between hosts or pools without shared storage (while the VM is running) • Resource pools: flexible storage and networking • Event tracking: progress, notification • Upgrade and patching capabilities • Real-time performance monitoring and alerting • Templates for Windows and Linux guests • Open vSwitch support built-in (default) More info: wiki.xenproject.org/wiki/XCP_Release_Features
- 36. XAPI : two variants… Multiple Hosts Additional Functionality XAPI / XE Xen Hypervisor XCP ISO (at v1.6) Xen 4.1.3 + XAPI CentOS 5.3 Kernel (v2.6.32.43) OVS 1.4.2 XCP-XAPI packages Debian Wheezy Ubuntu 12.04 LTS Others in progress …
- 37. XAPI : Orchestration and UIs Multiple Hosts Additional Functionality XAPI / XE Xen Hypervisor
- 38. Challenges for FOSS hypervisors
- 39. “Security and QoS/Reliability are amongst the top 3 blockers for cloud adoption” www.colt.net/cio-research
- 40. System characteristics cloud users care about: “Robustness, Performance, Scalability & Security” Results XCP User Survey 2012 – 90% of users quoted these as most important attributes
- 41. Split Control Domain into Driver, Stub and Service Domains – See: ”Breaking up is hard to do” @ Xen Papers – See: “Domain 0 Disaggregation for XCP and XenServer” Used today by Qubes OS and Citrix XenClient XT Prototypes for XAPI Disaggregation See qubes-os.org Different windows run in different VMs
- 42. More Security Increased serviceability and flexibility Better Robustness Better Performance Better Scalability Benefits of Disaggregation Ability to safely restart parts of the system (e.g. just 275ms outage from failed Ethernet driver)
- 43. Next: XAPI Architecture Diagram Before and After Disaggregation
- 44. CPUCPU RAM RAMNIC (or SR- IOV VF) NIC (or SR- IOV VF) NIC (or SR- IOV VF) NIC (or SR- IOV VF) RAID Xen Dom0Network drivers NFS/ iSCSI drivers Qemu xapi Local storage drivers NFS/ iSCSI drivers Network drivers Qemu eth eth eth eth scsi User VM User VM NB gntdev NB NF BF NF BF qemu qemu xapi vswitch networkd tapdisk blktap3 storaged syslogd vswitch networkd tapdisk blktap3 storaged tapdisk blktap3 storaged gntdev gntdev Dom0 xenopsd libxl healthd Domain manager Dom0 . . . . Xen xapi
- 45. CPUCPU RAM RAMNIC (or SR- IOV VF) NIC (or SR- IOV VF) NIC (or SR- IOV VF) NIC (or SR- IOV VF) RAID Dom0 Network driver domain NFS/ iSCSI driver domain Qemu domain xapi domain Logging domain Local storage driver domain NFS/ iSCSI driver domain Network driver domain User VM User VM NB gntdev NB NF BF NF BF dbus over v4v qemu xapi xenopsd libxl healthd Domain manager vswitch networkd tapdisk blktap3 storaged syslogd vswitch networkd tapdisk blktap3 storaged tapdisk blktap3 storaged gntdev gntdev eth eth eth eth scsi Xen Xen D o m 0 dbus over v4v . . .
- 46. 46 Xen Security Advantages • Even without Advanced Security Features – Well-defined trusted computing base (much smaller than on type-2 HV) – Minimal services in hypervisor layer • Xen Security Modules (or XSM) and FLASK – XSM is Xen equivalent of LSM – FLASK is Xen equivalent of SELinux – Developed, maintained and contributed to Xen by NSA – Compatible with SELinux (tools, architecture) – XSM object classes maps onto Xen features More info: http://www.slideshare.net/xen_com_mgr/ a-brief-tutorial-on-xens-advanced-security-features
- 47. CPUCPU RAM RAMNIC (or SR- IOV VF) NIC (or SR- IOV VF) NIC (or SR- IOV VF) NIC (or SR- IOV VF) RAID Xen Dom0 Network driver domain NFS/ iSCSI driver domain Qemu domain xapi domain Logging domain Local storage driver domain NFS/ iSCSI driver domain Network driver domain eth eth eth eth scsi User VM User VM NB gntdev NB NF BF NF BF qemu xapi xenopsd libxl healthd Domain manager vswitch networkd tapdisk blktap3 storaged syslogd vswitch networkd tapdisk blktap3 storaged tapdisk blktap3 storaged gntdev gntdev FLASK policy restricting access D o m 0 . . . dbus over v4v dbus over v4v Xen
- 48. ARM Hypervisor
- 49. Fully functional for ARM v7 & v8 ARM v7: Versatile Express, Arndale & Samsung Chromebook ARM v8: Fast Model Xen 4.3 for ARM Servers
- 50. ARM SOC Xen + ARM = a perfect Match ARM Architecture Features for Virtualization Hypervisor mode : EL2 Kernel mode : EL1 User mode : EL0 GIC v2 GT 2 stage MMU I/O Device Tree describes … Hypercall Interface HVC
- 51. ARM SOC ARM Architecture Features for Virtualization EL2 EL1 EL0 GIC v2 GT 2 stage MMU I/O Device Tree describes … HVC Xen + ARM = a perfect Match Xen Hypervisor
- 52. ARM SOC ARM Architecture Features for Virtualization EL2 EL1 EL0 GIC v2 GT 2 stage MMU I/O Device Tree describes … HVC Xen + ARM = a perfect Match Xen Hypervisor Any Xen Guest VM (including Dom0) Kernel User Space HVC
- 53. ARM SOC ARM Architecture Features for Virtualization EL2 EL1 EL0 GIC v2 GT 2 stage MMU I/O Device Tree describes … HVC Xen + ARM = a perfect Match Xen Hypervisor Dom0 only Any Xen Guest VM (including Dom0) Kernel User Space I/O PV back PV frontI/O HVC
- 54. One mode to rule them all x86: PVHVM P P VS VH x86: PVH P P P VH ARM v7 & v8 P VH VH VH Scope for improvement Optimal performance HVM mode/domain PV mode/domain
- 55. Code Size of x86 and ARM Hypervisors X86 Hypervisor 100K -120K LOC Any x86 CPU ARM Hypervisor for mobile Devices 60K LOC ARM v5 – v7 (no virtual extensions) (extra code for RT) ARM Hypervisor for Servers 17K LOC ARM v7+ (w/ virtual extensions)
- 56. Mirage OS
- 57. Application stacks only running on Xen APIs Works on any Xen based cloud or hosting service Examples – ErlangOnXen.org : Erlang – HalVM : Haskell – Mirage OS : Ocaml Benefits: – Small footprint – Low startup latency – Extremely fast migration of VMs Library Operating Systems Xen Control domain (dom0) Host HW Guest VMn Apps HW Drivers PV Back Ends Library OS embedded in Language run-time Dom0 Kernel
- 58. • Recently added to Xen Project incubator • In beta stage: first release on its way • Clean-slate protocols implementations, e.g. – TCP/IP, DNS, SSH, Openflow (switch/controller), HTTP, XMPP, ... – New applications using next generation XAPI (disaggregated XAPI architecture) Mirage OS More info: http://www.slideshare.net/xen_com_mgr/ mirage-extreme-specialisation-of-virtual-appliances
- 59. What’s Next?
- 60. • Release Candidate 4 Test Day on 6/12 • Xen ARM for Servers • Extend scope of Xen Security Modules • qxl Spice support for 3d acceleration • Updated and improved libvirt drivers for Xen • Lots of other stuff: – scalability, performance, better NUMA support, … Coming in Xen 4.3 (June 2013) More info: http://wiki.xenproject.org/wiki/Xen_Roadmap/4.3
- 61. • Establish a shared test infrastructure – Most major contributors are duplicating effort – Mirage OS provides interesting opportunities • Usability and better distribution integration – Example: Xen + XAPI in CentOS 6.4 • More focus on downstreams – Examples: OpenStack and Xen Orchestra • Disaggregation in Xen toolstacks (e.g XAPI) • Better Libvirt and virt-manager integration – Embed Xen more into the Linux ecosystem and provide benefits for the wider Linux community What’s next (and already happening)
- 62. • Document Days (monthly) • Test Days (prior to release) • Mailing Lists and IRC • XenProject.org (sign up, it’s free!) Getting Started with Xen Project Xen Hackathon & Developer Summit (annually; vote for next year’s location in the Q&A section of XenProject.org until June 14, 2013)
- 63. Thank You! Slides available under CC-BY-SA 3.0 From www.slideshare.net/xen_com_mgr @RCPavlicek Skype: russpavlicek • News: blog.XenProject.org • Web: XenProject.org – Help for IRC, Lists, … – Stackoverflow like Q&A • Wiki: wiki.XenProject.org • Presentations: slideshare.net/xen_com_mgr • Videos: vimeo.com/channels/xen