Instantly switch between TC and windows XP

[Ulysses_]

Someone must have thought of this, and you in-depth guys may have some idea how it could be done.  

Is it possible to switch between linux and windows XP instantly?  Half the memory being used by linux, half being used by windows xp, and switching between the two at the press of a button?

I am NOT talking about virtual machines, but actual, full-speed operating systems running on physical hardware.

Obviously this would require very low-level tweaking. Very low-level knowledge of what is going on in the linux kernel and windows xp.

Any thoughts on this? Or you know who to ask?

[curaga]

Many products do this, but they are always VMs, both of them, Win and Lin.

The only thing running on the hw in these cases is the hypervisor, which can be fairly low level.

[vinnie]

I do not know if it would help, but Xen is a "different" type of virtualization.
http://en.wikipedia.org/wiki/Xen

[curaga]

Or you could run linux on the base, with a Windows VM running full screen on one virtual desktop. I've seen that solution too.

[Ulysses_]

I do not know if it would help, but Xen is a "different" type of virtualization.
http://en.wikipedia.org/wiki/Xen

I happen to be aware of xen, but it's only for linux, both host and guests.  But what about windows XP tweaking to achieve something similar?

[Ulysses_]

Many products do this, but they are always VMs, both of them, Win and Lin.

The only thing running on the hw in these cases is the hypervisor, which can be fairly low level.

Actually vmware is running certain parts of user software at full speed, eg a function that does not access memory or peripherals, most machine code instructions are NOT emulated.

[Ulysses_]

Or you could run linux on the base, with a Windows VM running full screen on one virtual desktop. I've seen that solution too.

Running full speed because of a special cpu support, called V or something like that?

EDIT: Oopsa, I misread full screen as full speed, sorry.

[vinnie]

vbox require "guest-addiction" driver to v.machine at max, the combination left-ctrl + f switch on full screen.
vmware have full screen, but i use this only on windows.

[maro]

... vbox require "guest-addiction" driver to v.machine at max ...

That is simply INCORRECT! VBox does not need the VBox-additions to be installed in the guest OS to run the guest OS at the maximum speed. The achievable speed depends on the HW of the host e.g. whether it supports Intel's VT-x or AMD-V or non of them. The VBox-additions have as such no influence on this, they are rather supporting (optional) features like mouse integration, video drivers, shared folders etc.

I personally use VBox (and QEMU) a lot and hardly ever use the VBox-additions for TC VMs. I'm happy to use Xvesa, instead of Xorg which one would need to use with the VBox-additions video driver to gain anything from it.

[Ulysses_]

Off-topic question: With a VT-x/AMD-V cpu can you run a windows xp guest on a linux host at full speed?  What if the linux host is 64-bit and the xp guest is 32-bit?

[vinnie]

@maro: Using guestsaddiction you have more control over the resolution of the system (if I remember well even the automatic scaling based on vbox window size).
Automatically i think it's a useful option for similar needs.

[curaga]

Off-topic question: With a VT-x/AMD-V cpu can you run a windows xp guest on a linux host at full speed?  What if the linux host is 64-bit and the xp guest is 32-bit?

There's always overhead, but with those extensions it's very close to full speed. Something like 97%.

A 64-bit host can run both 64 and 32-bit guests.

[maro]

Off-topic question: With a VT-x/AMD-V cpu can you run a windows xp guest on a linux host at full speed?  What if the linux host is 64-bit and the xp guest is 32-bit?

Well, in principle I'd say YES, but currently there is no 64-bit extension for the VBox kernel modules in the repository (i.e. 'virtualbox-ose-modules-2.6.33.3-tinycore64.tcz'). According to this message it appears not to be an oversight, but I'm not sure what the problem might be (AFAIK those modules have been compiled for other 64-bit distributions).

So far I never saw the need to use MC 64-bit, but as I have now access to a notebook with a VT-x 64-bit CPU I gave it a try. I've only done a quick test using MC 3.5.1 (64-bit) as host OS and 'qemu.tcz' plus the 64-bit 'kvm' extension. This extension is a bit dated, but I had no immediate problem in running TC 3.5.1 (32-bit) as guest OS. Mind you I did not do a proper test, just a quick run of 'glxgears' IIRC. Another attempt with a 64-bit guest lead to a segfault, but I'm not sure that I can be bothered to look further into this.

[curaga]

Qemu's default 64-bit cpu is a bit buggy, I use -cpu core2duo (or kvm64 when on kvm). kvm64 is the default when using kvm only in 0.14 or later, I believe.

[gutmensch]

Btw. there's an interesting product from Citrix called XenClient, it's a bare metal hypervisor for special notebooks like Lenovo T series, Dell latitude, etc. It's by design maybe the closest approach to be able to switch easily between OS's (like Ctrl+1 for Windows, Ctrl+2 for Windows). It's based of course on Linux - and the guest support for Linux is non-existent, since they prefer to support Windows (guess because of the money involved) When you have a XenServer running you can additionally synchronize VMs to and from your Notebook. All in all: Very interesting but not a good catch in performance to the day.