I have gone through the E38xx External Design specification document (Document ID: 510858) and it mentions that E38xx supports MSI interrupts. Whether MSI included both MSI as well as MSIX interrupts? Kindly confirm.
I confirmed that MSIX is also supported. I see that the EDS is an Intel confidential document so I assume that and Intel rep assisted in getting you the document. By the way, it is also on the Embedded Design Center (EDC). If you would like to get a Privileged account, go to http://www.intel.com/content/www/us/en/intelligent-systems/membership/edc-member-benefits-faq.html Intel® Embedded Design Center Member Benefits FAQ and click on "Apply for Privileged access". This way you can use the EDC and quickly access Intel confidential content.
Uday, I was also told that PCI Express expands to the MSI spec (MSI-X) to include not just interrupts but all side-band control signals.