* Zachary Amsden (zach@xxxxxxxxxx) wrote: > Allow compile time creation of a hole at the high end of linear address space. > This makes accomodating a hypervisor a much more tractable problem by giving > it ample playground to live in. Currently, the hole size is fixed at config > time; I have experimented with dynamically sized holes, and have a later > patch that developes this potential, but it becomes much more useful once > the exact negotiation of linear address space with the hypervisor is defined. > > The fixed compile time solution is sufficient for now. Xen moves __FIXADDR_TOP like this: #ifdef CONFIG_X86_PAE # define HYPERVISOR_VIRT_START (0xF5800000UL) #else # define HYPERVISOR_VIRT_START (0xFC000000UL) #endif and #define __FIXADDR_TOP (HYPERVISOR_VIRT_START - 2 * PAGE_SIZE) and also adds bits to fixmap. So this proposed mechanism isn't quite good enough. thanks, -chris
