Hi, I'm trying to use a 64-bit BAR for my shared memory device. In simply changing the memory type in pci_register_bar() to PCI_BASE_ADDRESS_MEM_TYPE_64 I get an unusual physical address for that BAR (and my driver crashes in pci_ioremap).
from lspci: 00:04.0 RAM memory: Qumranet, Inc. Device 1110 Subsystem: Qumranet, Inc. Device 1100 Flags: fast devsel, IRQ 10 Memory at f1020000 (32-bit, non-prefetchable) [size=1K] Memory at f1021000 (32-bit, non-prefetchable) [size=4K] Memory at c20000000000 (64-bit, non-prefetchable) [size=1024M] Capabilities: <access denied> 00: f4 1a 10 11 03 00 10 00 00 00 00 05 00 00 00 00 10: 00 00 02 f1 00 10 02 f1 04 00 00 00 00 c2 00 00 20: 00 00 00 00 00 00 00 00 00 00 00 00 f4 1a 00 11 30: 00 00 00 00 40 00 00 00 00 00 00 00 0b 01 00 00 with DEBUG_MEMREG, I see kvm_unregister_memory_area:666 Unregistering memory region c20000000000 (40000000) kvm_destroy_phys_mem:649 slot 7 start c20000000000 len 0 flags 0 IVSHMEM: addr = 3221225472 size = 1073741824 kvm_register_phys_mem:605 memory: gpa: c200c0000000, size: 40000000, uaddr: 7f6dd7ffe000, slot: 7, flags: 0 kvm_unregister_memory_area:666 Unregistering memory region c200c0000000 (40000000) kvm_destroy_phys_mem:649 slot 7 start c200c0000000 len 0 flags 0 IVSHMEM: addr = 0 size = 1073741824 kvm_register_phys_mem:605 memory: gpa: c20000000000, size: 40000000, uaddr: 7f6dd7ffe000, slot: 7, flags: 0 kvm_unregister_memory_area:666 Unregistering memory region c20000000000 (40000000) kvm_destroy_phys_mem:649 slot 7 start c20000000000 len 0 flags 0 IVSHMEM: addr = 0 size = 1073741824 kvm_register_phys_mem:605 memory: gpa: ffffffff00000000, size: 40000000, uaddr: 7f6dd7ffe000, slot: 7, flags: 0 kvm_unregister_memory_area:666 Unregistering memory region ffffffff00000000 (40000000) kvm_destroy_phys_mem:649 slot 7 start ffffffff00000000 len 0 flags 0 IVSHMEM: addr = 0 size = 1073741824 kvm_register_phys_mem:605 memory: gpa: c20000000000, size: 40000000, uaddr: 7f6dd7ffe000, slot: 7, flags: 0 (the IVSHMEM lines are my debug statements) address sizes : 40 bits physical, 48 bits virtual (guest) address sizes : 38 bits physical, 48 bits virtual (host) Thanks, Cam