Would a new forum for Virtual machines and Dual booting be good?

It is complicated, I even had trouble creating it.

But getting back to the guy with the WinModem.

If Windows is the base, and Linux is in the Virtual Machine, he can use the WinModem from Windows and still have Linux running but without the WinModem.

If Linux is the base, and Windows is in the Virtual Machine, then he can't get the WinModem.

Yes or No?

Originally Posted by Chris Stegman Configuration 1: Windows XP is the base OS with virtual machine running Linux. Drivers for Device A are installed in Windows XP. Drivers for Device B are installed in Windows XP. Device A will run for Windows XP. Device B will run for Windows XP. Drivers for Device A are installed in Linux. Drivers for Device B cannot be installed for Linux because they don't exist. Device A will run for Linux in the virtual machine because it is using Virtual Machine's emulated device. Device B will not run for Linux in the virtual machine because the drivers do not exist.

It's simpler than that. We have to OS's: OS1 and OS2. We are running OS2 as a guest into a VM inside OS1. Then, for a device to work ok on OS2 you need the following:

• OS1 must have support for it (a driver must exist and be loaded)
• The VM must support it, if the VM can't remap the hardware device to a virtual device inside it, then OS2 can't see it
• OS2 must support the virtual device, and not the hardware one, this usually can be done via a generic driver like in the cirrus logic case we spoke before, or via an emulated driver supplied by the VM itself.

In other words, you only need the drivers for the physical hardware on the host OS, in this case OS1. You will need drivers in OS2, but not necessarily the same driver nor for the same device, since the device that OS2 will see is not the same device that OS1 sees.


Now, change OS1 and OS2 with whatever OSes you want, it's the same.

Originally Posted by i92guboj It's simpler than that. We have to OS's: OS1 and OS2. We are running OS2 as a guest into a VM inside OS1. Then, for a device to work ok on OS2 you need the following: OS1 must have support for it (a driver must exist and be loaded) The VM must support it, if the VM can't remap the hardware device to a virtual device inside it, then OS2 can't see it OS2 must support the virtual device, and not the hardware one, this usually can be done via a generic driver like in the cirrus logic case we spoke before, or via an emulated driver supplied by the VM itself. In other words, you only need the drivers for the physical hardware on the host OS, in this case OS1. You will need drivers in OS2, but not necessarily the same driver nor for the same device, since the device that OS2 will see is not the same device that OS1 sees. Now, change OS1 and OS2 with whatever OSes you want, it's the same.

Thanks for the clarification.

The fact I am trying to verify and convey is that is is possible to have a hardware device work in a virtual machine with OS1 base, OS2 virtual, yet not work in a virtual machine with OS2 base, 0S1 virtual. In other words, it does matter which OS is the base for some devices.

Originally Posted by Chris Stegman Thanks for the clarification. The fact I am trying to verify and convey is that is is possible to have a hardware device work in a virtual machine with OS1 base, OS2 virtual, yet not work in a virtual machine with OS2 base, 0S1 virtual. In other words, it does matter which OS is the base for some devices.

Yes. It could.

The most important thing is that you need support in OS1, so the VM can see the device. Once the VM can see it and if it can handle it, then it will expose an emulated device to OS2. How it will be mapped and detected, and whether you will be able to use it to its full potential can depend in a number of things.

For example, I think that qemu emulates a cirrus logic graphics card. So, you really only need support for your true graphics card on OS1, once OS1 can use your hardware, the VM will fake a cirrus logic card, and as long as OS2 can use a cirrus logic video card then you will be able to use OS2 without problems. So, you will be able to see things in your screen, even if OS2 doesn't have a proper driver for your display.

It's a bad example anyway because most OSes nowadays would work in vesa mode if nothing else, but I hope you can get my point.

The same goes for network cards. If you get your connection working under windows, then installing linux into a vm should be a breeze, because it would fake the network interfaces with generic ones that are known to work well, and it doesn't matter if linux doesn't support your nic or wifi card.

Jesús Guerrero,

Thanks for answering the detailed questions with clear explanations. Having used virtual machines for years it is nice to hear someone else talk about it in the same light.