If the message is belonging to the follow two kinds of questions; Please refer to >RedHat Knowledgebase for more information.
1)PCI:BIOS Bug:MCFG area at e0000000 is not E820-reserved
2)PCI:NOT Using MMCONFIG
Issue:
What does the "PCI:BIOS Bug:MCFG" message seen at startup mean?Resolution:During system startup these two messages may appear on the console and in /var/log/messages (possibly with a different address value in the first message):
PCI:BIOS Bug:MCFG area at e0000000 is not E820-reserved
PCI:NOT Using MMCONFIG
These two messages may be treated as informational. Using MMCONFIG for PCI config space access is an optimization, not a requirement.
The MCFG area is not trusted by the kernel unless the E820 BIOS call reports that the area is reserved. It is possible that a BIOS update will correct the problem, but the system will work fine as it is.
In a future kernel version, these messages may be classified as INFO instead of ERR, so they don't show on the console.
