On 10/1/07, Anthony Liguori <[EMAIL PROTECTED]> wrote: > Cameron Macdonell wrote: > > Hi, > > > > I'm trying to understand guest virtualization at the lower levels. I > > have a somewhat basic question: How does KVM virtualize an int80 > > instruction from a guest? A pointer to an answer is just as good as > > an answer itself. > > > > The same thing happens as it does on normal hardware. > > The way VT/SVM works (at a high level), is that certain instructions and > events check a special area called the VMCS/VMCB to determine whether > the event should generate a vmexit which is really just a special type > of trap. > > There are no hooks for interrupts 32-255 so the hardware operates as it > normally would. If you're interested in getting a trap for int80 within > KVM, you'll have to trap sidt/lidt and virtualize the IDT. You'll need > to setup a fake IDT and have the int80 handler do a hypercall. This is > complicated if the guest is using a fast-syscall mechanism. It may be a > little challenging finding a piece of guest memory to take over that has > a valid virtual mapping.
This is a bit vague to me. Why do you need "a piece of guest memory" here? Thanks, Jun ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2005. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
