Description of problem:
Your BIOS is broken; DMAR reported at address fed90000 returns all ones!


Version-Release number of selected component (if applicable):
kernel-3.7.2-201.fc18.x86_64

How reproducible:


Steps to Reproduce:
1. try to boot kernel

  
Actual results:
[    0.000000] WARNING: at drivers/iommu/dmar.c:481 warn_invalid_dmar+0x86/0xa0()
[    0.000000] Hardware name: HP xw4600 Workstation
[    0.000000] Your BIOS is broken; DMAR reported at address fed90000 returns all ones!
BIOS vendor: Hewlett-Packard; Ver: 786F3 v01.34; Product Version:  
[    0.000000] Modules linked in:
[    0.000000] Pid: 0, comm: swapper Not tainted 3.7.2-201.fc18.x86_64 #1
[    0.000000] Call Trace:
[    0.000000]  [<ffffffff8105e67f>] warn_slowpath_common+0x7f/0xc0
[    0.000000]  [<ffffffff8105e71f>] warn_slowpath_fmt_taint+0x3f/0x50
[    0.000000]  [<ffffffff81d10a8a>] ? __early_set_fixmap+0x99/0xa0
[    0.000000]  [<ffffffff81500c46>] warn_invalid_dmar+0x86/0xa0
[    0.000000]  [<ffffffff81d3a9c3>] check_zero_address+0xc8/0xf7
[    0.000000]  [<ffffffff81641909>] ? bad_to_user+0x7b3/0x7b3
[    0.000000]  [<ffffffff81d3aa09>] detect_intel_iommu+0x17/0xb9
[    0.000000]  [<ffffffff81d035b4>] pci_iommu_alloc+0x4a/0x73
[    0.000000]  [<ffffffff81d10849>] mem_init+0x19/0xed
[    0.000000]  [<ffffffff81629945>] ? set_nmi_gate+0x48/0x4a
[    0.000000]  [<ffffffff81cfba56>] start_kernel+0x1e3/0x3d4
[    0.000000]  [<ffffffff81cfb672>] ? repair_env_string+0x5e/0x5e
[    0.000000]  [<ffffffff81cfb356>] x86_64_start_reservations+0x131/0x135
[    0.000000]  [<ffffffff81cfb45a>] x86_64_start_kernel+0x100/0x10f
[    0.000000] ---[ end trace 5b114c5af6db535a ]---

Expected results:
no warning

Additional info:
it shows up on Hardware name: HP xw4600 Workstation