Hello, while it feels like we had a similar situation before, I can't seem to be able to find traces thereof, or associated (Linux) commits.
With (XEN) Dom0 kernel: 64-bit, PAE, lsb, paddr 0x1000000 -> 0x4000000 ... (XEN) Dom0 alloc.: 0000000440000000->0000000448000000 (619175 pages to be allocated) ... (XEN) Loaded kernel: ffffffff81000000->ffffffff84000000 the kernel occupies the space from 16Mb to 64Mb in the initial allocation. Page tables come (almost) directly above: (XEN) Page tables: ffffffff84001000->ffffffff84026000 I.e. they're just above the 64Mb boundary. Yet sadly in the host E820 map there is (XEN) [0000000004000000, 0000000004009fff] (ACPI NVS) i.e. a non-RAM range starting at 64Mb. The kernel (currently) won't tolerate such an overlap (also if it was overlapping the kernel image, e.g. if on the machine in question s sufficiently much larger kernel was used). Yet with its fundamental goal of making its E820 match the host one I'm also in trouble thinking of possible solutions / workarounds. I certainly do not see Xen trying to cover for this, as the E820 map re-arrangement is purely a kernel side decision (forward ported kernels got away without, and what e.g. the BSDs do is entirely unknown to me). Jan