Linux Kernel to Include KVM Virtualization 194
It looks like the newest version of the Linux kernel (2.6.20) will include KVM, the relatively new virtualization environment. From the article: "Thanks to its approach KVM already runs in the current kernel, without any extensive bouts of patching and compiling being required, after the fairly simple compilation of a module. Virtual machines that run unmodified operating systems are meant to appear in the host as a simple process and work independently of the host kernel. In a fashion comparable to that of Xen a modified QEMU is used for the supportive emulation of typical PC components of the virtual machines."
Re:how many KVMs (Score:3, Insightful)
Only up to date processors? How up to date? (Score:3, Insightful)
Re:KVM switch? (Score:2, Insightful)
> (I have two mice connected as the switch cannot switch the mice correctly)
Keyboard and mouse data comes in packets of about 3 or 4 bytes. If a KVM switch toggles mid-packet the PC and/or the peripheral may get badly confused. A well-designed KVM product will get this right, but many don't; it looks like your Belkin product falls into this category.
KVM swithces also vary enormously in their video quality. It is a mistake to think of a KVM switch as a "commodity" device. It is well worth spending a bit extra to get a well-designed product. You're unlikely to have any problems with Adder or Avocent kit.
I hope Windows can't access the hardware. (Score:2, Insightful)
Re:qemu (Score:1, Insightful)
Re:Not everything, just video (Score:3, Insightful)
If the full interface documentation for recent Nvidia and ATI video cards was released, and GPL-compatible drivers existed, this would probably already be in the works.
Re:Not everything, just video (Score:1, Insightful)
The PC architecture (and I use the term loosely...) simply doesn't have proper memory protected I/O "channels" like mainframe I/O. (I dunno about PCI Express, since it's a cut-down channel architecture, maybe it, maybe in conjunction with an AMD-syle x86_64 IOMMU, could properly memprotect all thos noncpu processors modern PeeCees tend to have).
Re:qemu (Score:3, Insightful)
Re:Not everything, just video (Score:3, Insightful)
Re:Not everything, just video (Score:3, Insightful)
Games may be an inhibitor for Linux adoption in the home market, but Xen/QEmu/KVM/VMWare aren't aimed at the home market at all. When you consider the fact that what you want is most definitely not a simple task, you may understand why nobody has done it yet.
Re:Not everything, just video (Score:3, Insightful)
If it locks up the video sub system it can make the machine unusable except via a net or dumb terminal connection , which could mean the machine needs a reboot. Not good in a business enviroment.
Re:I hope Windows can't access the hardware. (Score:5, Insightful)
If you don't know, please leave your geek-card at the door on your way out.
Short answer - DMA. [wikipedia.org]
Long answer - memory protection between processes (and in this case guest OSes) is done by the MMU, making sure that process A can't read/write to memory owned by process B (or in this case guest OS and host OS). Unfortunately, the memory space seen by devices on extention buses like PCI is not mapped by the MMU. If a process has direct access to a device that supports DMA, it can tell the device to read or write memory that belongs to other processes (f.ex. order the sound card to read the sound buffer from kernel space. The process can then read the sound buffer to get access to kernel memory).
To safely allow a process (or guest OS) direct access to hardware devices, the hardware architecture and OS needs to be designed so that a DMA from the hardware device can only access memory owned by the process that ordered the DMA.
What is the big deal? (Score:2, Insightful)
I understand we are talking about virtual machines that is multiple OS's running on the same machine simultaneously.
My question is: what does that offer me? Other then possibly running a linux and XP on my home machine what could that possibly offer anyone?
Thanx
Julian