Zachary Amsden wrote: > Chuck Ebbert wrote: >> In-Reply-To: <20060315102522.GA5926@xxxxxxxxxxxxx> >> >> On Wed, 15 Mar 2006 10:25:22 +0000, Christoph Hellwig wrote: >> I'd like to see a test harness implementation that has no actual >> hypervisor functionality and just implements the VMI calls natively. >> This could be used to test the interface and would provide a nice >> starting point for those who want to write a VMI hypervisor. >> > > I was going to make one yesterday. But Fry's electronics stopped > carrying flashable blank PCI cards. :) Anyone know of a vendor? It's very practical to just patch Qemu to load a VMI rom as an option ROM. That makes such an example VMI ROM very practical without having to build a special PCI device. Regards, Anthony Liguori > It is possible to do in a software layer, although it really is a lot > easier to have the BIOS take care of all the fuss of finding a place > in low memory for you to live, setting up the various memory maps and > everything else for you. > > There is enormous benefit to having such a layer - you have a very > power test harness, not just to make sure VMI works, but even more > importantly, to inspect and verify the native kernel operation as > well. You have a plethora of imporant hooks into the system, which > feed you knowledge you can not otherwise gain about which page tables > have been made active, when you take IRQs, where the kernel stack lives. > > All of this is ripe for a debug harness that can verify the kernel > doesn't overflow the kernel stack, doesn't write to active page table > entries without proper accessors and subsequent invalidations, and > obeys the rules that are required for correctness when running under a > hypervisor. You probably even want to do hypervisor like things - > such as write protecting the kernel page tables so that you can be > confident there are no stray raw PTE accesses. > > We actually found one (harmless on native) in i386, which was enabling > NX bit. > > Zach > > _______________________________________________ > Xen-devel mailing list > Xen-devel@xxxxxxxxxxxxxxxxxxx > http://lists.xensource.com/xen-devel
