1. Windows Virtual PC / Hyper-V
Student: Mariana-Madalina Nastase

2. Contents: Windows Virtual PC Hyper-V Reasons to use virtualization
System requirements
Hyper-V Architecture
Operating systems you can run in a virtual machine
Hyper-V on Windows VS Hyper-V on Windows Server
Limitations
References

3. Windows Virtual PC
Windows Virtual PC is a virtualization program for Microsoft Windows. In July 2006 Microsoft released the Windows version as a free product.
Connectix Virtual PC, Microsoft Virtual PC 2004, Microsoft Virtual PC 2007, and Windows Virtual PC are successive versions of the same software. Windows Virtual PC runs only on Windows 7 and only supports running Windows XP Professional and later. The earlier Microsoft versions which run on older versions of Windows are still available and support operating systems older than Windows XP. Microsoft then replaced this with Hyper-V.

4. On July 12, 2006, Microsoft released Virtual PC 2004 SP1 for Windows free of charge, but the Mac version was not made free. The equivalent version for Mac, version 7, was the final version of Virtual PC for Mac. It ran on Mac OS X  or later for PowerPC and was a proprietary commercial software product.
Virtual PC 2007 was released only for the Windows platform, with public beta testing beginning October 11, 2006, and production release on February 19, It added support for hardware virtualization, viewing virtual machines on multiple monitors and support for Windows Vista as both host and guest.
Microsoft Virtual PC (2004 and 2007) does not work at all on Windows bit, and even on 32-bit platforms lack internet connectivity due to the lack of the VPC driver.

5. HYPER-V
Whether you are a software developer, an IT professional, or a technology enthusiast, many of you need to run multiple operating systems. Hyper-V lets you run multiple operating systems as virtual machines on Windows.
Hyper-V specifically provides hardware virtualization. That means each virtual machine runs on virtual hardware. Hyper-V lets you create virtual hard drives, virtual switches, and a number of other virtual devices all of which can be added to virtual machines.

6. A beta version of Hyper-V was shipped with certain x86-64 editions of Windows Server The finalized version was released on June 26, 2008 and was delivered through Windows Update. Hyper-V has since been released with every version of Windows Server.
Microsoft provides Hyper-V through two channels:
Part of Windows: Hyper-V is an optional component of Windows Server 2008 and later. It is also available in x64 SKUs of Pro and Enterprise editions of Windows 8, Windows 8.1 and Windows 10.
Hyper-V Server: It is a freeware edition of Windows Server with limited functionality and Hyper-V component.

7. Reasons to use virtualization
Virtualization allows you to:
Run software that requires an older versions of Windows or non-Windows operating systems.
Experiment with other operating systems. Hyper-V makes it very easy to create and remove different operating systems.
Test software on multiple operating systems using multiple virtual machines. With Hyper-V, you can run them all on a single desktop or laptop computer. These virtual machines can be exported and then imported into any other Hyper-V system, including Azure.

8. System requirements
Hyper-V is available on 64-bit versions of Windows 10 Pro, Enterprise and Education. It is not available on the Home edition.
Most computers will run Hyper-V however each virtual machine is a completely separate operating system. You can generally run one or more virtual machines on a computer with 4GB of RAM, though you'll need more resources for additional virtual machines or to install and run resource intense software like games, video editing, or engineering design software.

9. Architecture
Hyper-V supports isolation in terms of a partition. A partition is a logical unit of isolation, supported by the hypervisor, in which operating systems execute. The Microsoft hypervisor must have at least one parent, or root, partition, running Windows. The virtualization management stack runs in the parent partition and has direct access to hardware devices. The root partition then creates the child partitions which host the guest operating systems. A root partition creates child partitions using the hypercall application programming interface (API).

10. Partitions do not have access to the physical processor, nor do they handle the processor interrupts. Instead, they have a virtual view of the processor and run in a virtual memory address region that is private to each guest partition. The hypervisor handles the interrupts to the processor, and redirects them to the respective partition. Hyper-V can also hardware accelerate the address translation between various guest virtual address spaces by using an Input Output Memory Management Unit (IOMMU) which operates independent of the memory management hardware used by the CPU. An IOMMU is used to remap physical memory addresses to the addresses that are used by the child partitions.

11. Child partitions also do not have direct access to other hardware resources and are presented a virtual view of the resources, as virtual devices (VDevs). Requests to the virtual devices are redirected either via the VMBus or the hypervisor to the devices in the parent partition, which handles the requests. The VMBus is a logical inter-partition communication channel. The parent partition hosts Virtualization Service Providers (VSPs) which communicate over the VMBus to handle device access requests from child partitions. Child partitions host Virtualization Service Consumers (VSCs) which redirect device requests to VSPs in the parent partition via the VMBus. This entire process is transparent to the guest operating system.

12. Virtual Devices can also take advantage of a Windows Server Virtualization feature, named Enlightened I/O, for storage, networking, graphics, and input subsystems. Enlightened I/O is a specialized virtualization-aware implementation of high level communication protocols (such as SCSI) that utilize the VMBus directly, bypassing any device emulation layer. This makes the communication more efficient but requires an enlightened guest that is hypervisor and VMBus aware. Hyper-V enlightened I/O and a hypervisor aware kernel is provided via installation of Hyper-V integration services. Integration components, which include virtual server client (VSC) drivers, are also available for other client operating systems. Hyper-V requires a processor that includes hardware assisted virtualization, such as is provided with Intel VT or AMD Virtualization (AMD-V) technology.

14. Operating systems you can run in a virtual machine
Hyper-V on Windows supports many different operating systems in a virtual machine including various releases of Linux, FreeBSD, and Windows.
As a reminder, you'll need to have a valid license for any operating systems you use in the VMs.

15. Hyper-V on Windows VS Hyper-V on Windows Server
There are some features that work differently in Hyper-V on Windows than they do in Hyper-V running on Windows Server.
Hyper-V features only available on Windows Server:
Live migration of virtual machines from one host to another
Hyper-V Replica
Virtual Fiber Channel
SR-IOV networking
Shared .VHDX
Hyper-V features only available on Windows 10:
Quick Create and the VM Gallery
Default network (NAT switch)

16. Limitations
Programs that depend on specific hardware will not work well in a virtual machine. For example, games or applications that require processing with GPUs might not work well. Also, applications relying on sub-10ms timers such as live music mixing applications or high precision times could have issues running in a virtual machine.
In addition, if you have Hyper-V enabled, those latency-sensitive, high-precision applications may also have issues running in the host. This is because with virtualization enabled, the host OS also runs on top of the Hyper-V virtualization layer, just as guest operating systems do. However, unlike guests, the host OS is special in that it has direct access to all the hardware, which means that applications with special hardware requirements can still run without issues in the host OS.

17. References

18. Questions ???