Intel Xeon L3406 CM80616005010AA Manuale Utente

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Datasheet, Volume 2

bit. There is no decode enable bit for configuration cycle decoding towards either a 
PCIe port or the internal CSR configuration space of IIO.

• The target decoding for internal VTdCSR space is based on whether the incoming 

CSR address is within the VTdCSR range (limit is 8K plus the base, VTBAR). 

• Each PCIe/DMI port in IIO has one special address range - I/OxAPIC
• No loopback supported, that is, a transaction originating from a port is never sent 

back to the same port and the decode ranges of originating port are ignored in 
address decode calculations

This section talks about how IIO allows for access to flash memory that is resident 
below the IIO.

• FWH accesses using an IIO are allowed only from Intel QuickPath Interconnect. No 

accesses from JTAG/PCIe

• IIO indicates presence of bootable FWH to processor if it is with a FWH that 

contains the boot code below the legacy PCH connected to it

• All FWH addresses (4 GB:4 GB–16 MB) and (1 MB:1 MB – 128 K) that do not 

positively decode to IIO’s PCIe ports, are subtractively forwarded to its legacy 
decode port.

• When IIO receives a transaction from Intel QuickPath Interconnect within 4 GB:4 

GB–16 MB or 1 MB:1 MB–128 K and there is no positive decode hit against any of 
the other valid targets (if there is a positive decode hit to any of the other valid 
targets, the transaction is sent to that target), then the transaction is forwarded to 
DMI.

• Other address ranges (besides CSR, FWH, I/OxAPIC) that need to be decoded per 

PCIe/DMI port include the standard peer-to-peer bridge decode ranges (MMIOL, 
MMIOH, I/O, VGA, CONFIG). Refer to PCI-PCI Bridge 1.2 Specification and PCI 
Express Base Specification  for details. These ranges are also summarized in 

. 

• VTCSR

— Remote peer-to-peer accesses from Intel QuickPath Interconnect that target 

VTCSR region are not completer aborted by IIO. If inbound protection is 

needed, VTd translation table should be used to protect at the source IIO. If 

the VTd table is not enabled, a Generic Protected Memory Range could be used 

to protect. A last defense is to turn off IB peer-to-peer MMIO The remote peer-

to-peer support is an issue not yet closed completely yet.

— Remote peer-to-peer PCI configuration transactions from Intel QuickPath 

Interconnect that target the internal bus number of IIO (regardless of device 

number) are aborted by IIO.