Switch the initialization of gnttab to use an unused physical memory range for both PVHVM and PVH. In the past PVHVM was using the xenpci BAR, but there's no reason to do that, and in fact FreeBSD was probably doing it because it was the way it was done in Windows, were drivers cannot probably request for unused physical memory ranges, but it was never enforced in the hypervisor. Sponsored by: Citrix Systems R&D Approved by: gibbs xen/gnttab.c: - Allocate contiguous physical memory for grant table frames for both PVHVM and PVH. - Since gnttab is not a device, use the xenpv device in order to request for this allocation. dev/xen/xenpci/xenpcivar.h: dev/xen/xenpci/xenpci.c: - Remove the now unused xenpci_alloc_space and xenpci_alloc_space_int functions. xen/gnttab.h: - Change the prototype of gnttab_init and gnttab_resume, that now takes a device_t parameter. dev/xen/control/control.c: x86/xen/xenpv.c: - Changes to accomodate the new prototype of gnttab_init and gnttab_resume.