On Wed, Apr 27, 2016 at 10:41:32AM -0500, Alex Thorlton wrote: > A bit of digging will tell us that this is the failing line: > > m_n_config.v = uv_read_local_mmr(UVH_RH_GAM_CONFIG_MMR ); That looks like All code ======== 0: 65 48 03 05 1d b8 49 add %gs:0x7e49b81d(%rip),%rax # 0x7e49b825 7: 7e 8: 80 78 14 02 cmpb $0x2,0x14(%rax) c: ba 00 00 00 fa mov $0xfa000000,%edx 11: 76 0b jbe 0x1e 13: 48 89 c8 mov %rcx,%rax 16: 65 48 03 05 07 b8 49 add %gs:0x7e49b807(%rip),%rax # 0x7e49b825 1d: 7e 1e: 48 b8 00 00 60 01 00 movabs $0xffff880001600000,%rax 25: 88 ff ff 28: 48 09 d0 or %rdx,%rax 2b:* 48 8b 00 mov (%rax),%rax <-- trapping instruction 2e: 88 c3 mov %al,%bl 30: 48 c1 e8 06 shr $0x6,%rax 34: 41 bd 01 00 00 00 mov $0x1,%r13d 3a: 88 c1 mov %al,%cl 3c: 83 e3 3f and $0x3f,%ebx but why does this have anything to do with the EFI pagetable, at all? The MMRs should be mapped in the normal kernel page table, right? And your dirty fix of mapping into trampoline_pgd doesn't make any sense... How do the MMRs get mapped on that box exactly? And why aren't they mapped in the normal kernel page table all of a sudden? /me is confused and goes to bed. -- Regards/Gruss, Boris. SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg) -- -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html