G400E interrupts - try to unshare

Hi Atom2,

At present, G400P is not able to run on KVM. Meanwhile, G400P can not modify pins to avoid IRQ sharing over firmware upgrate. That's a plan,but it's not been released so far.

Hi Joe.Yung,
You said: "At present, G400P is not able to run on KVM. Meanwhile, G400P can not modify pins to avoid IRQ sharing over firmware upgrate. That's a plan,but it's not been released so far."

This is not in line with your own documentation, namely http://wiki.openvox.cn/index.php/Troubleshooting_of_PRI_cards , where you clearly state under question Q62 that the procedure described there also applies to the G400P: "Here taking D430P for an example to introduce how to use opvx-update. Note: This tool also applys to G400P,A2410P,D230 and D130.". Being able to reroute an interrupt is is a very important feature and should be released asap, not the least to be in line with the documentatiion and the expectations you set therein.

In any case, my question was about a G400E (the PCIe version) and I firstly do not understand why there are discrepancies between what you list in the installation manual and my output for "lspci -vvx": Your output connects to IRQ 66, my output uses one of the precious lower IRQ lines, namely 5. How can I change this? I don't think this is connected to the slot the card is in because in every slot my card uses one of the lower 15 interrupts.

Furthermore the manual for the G400E also clearly states at http://wiki.openvox.cn/index.php ... Installation_Manual under "additional function": "While G400E allows users to modify interrupt pin during firmware upgrade for avoiding conflict."

PCIe according to my knowledge is not limited to 16 interrupts and can use the MSI or MSIx method. This is indicated by the output in your installation manual where the card's pin A interrupt was routed to 66. My card uses 5 which is shared with another (legacy) PCI card in my system. For PCIe cards with lots of interrupts available there is absolutely no reason to share interrupt with legacy PCI cards.

The reason for me to buy PCIe cards (as opposed to the legacy PCI counterpart) was to avoid any issus with shared interrupts used by other legacy PCI cards in my system.

What about the A800e - also a PCIe card which uses one of the precious lower interrupts (11 in my case). This use also conflicts with another legacy PCI card installed in my system.

Regards Atom2

i] Last edited by Atom2 at 2012-5-30 17:36 [/i

Dear Atom2:
Are you trying to sue G400E with KVM software together or use G400e in KVM?

I doubt you could not use G400E in KVM, I do not know much about KVM, but it should be possible you run G400E in the main OS while KVM to run other applications.

At this moment, G400E still not support change irq pin, it need a new release of firmware. it could not support MSI type irterrupt due to design limitation.

A PCI system can only use 4 irq at the most accord to PCI Spec,

shared IRQ is not always a issue, share IRQ with busy device might lead to issue, for example, share irq with hdd or NIC controller, but if your system have more than 4 NIC, you could not avoide share irq.

Hi Atom2,

Perhaps I did not clear my point. The Q62 of the wiki means that the tool is apply to G400P. Yes, G400P is able to use this tool to update its firmware. But actually it only applies to the new generation cards(Like A810P/e, A1610P/e and A2410P/e, D130P/e, D230P/e and D430P/e, but not including G400P) for the pin revise. I think Q62 didn't make it perfectly clear.

One more thing, A800e is also not able to change the IRQ number by this tool. How about using our A810 instead?

Hi Joe.Yung,
I understand that there might have been an issue with not making it clear for the ++ G400P ++ in the manual. However, I am talking about a ** G400E ** - which is the PICe version of the card - and not the ++ G400P ++. For the ** G400E ** the manual under http://wiki.openvox.cn/index.php ... Installation_Manual is relevant which clearly states the following: "While G400E allows users to modify interrupt pin during firmware upgrade for avoiding conflict." So for the PCIe version I am using - the ** G400E ** - I should be able to change the interrupt pin!

Re your suggestion to use the A810 instead: Clearly that would be an option, however there are two issues: Firstly I do have the A800E which I then no longer would require and secondly as far as I understand the A810 is only available with 4 FXO plus 4 FXS slots. At the moment I do only require one port of each (probably more in the future, but I could most likely do with a total of 4). I don't know the cost of the A810 or the price difference to my current card, but I guess it boils down to a cost issue.

Clearly that is something where OpenVox could help - it it were a straight swap, I'd be more than happy to exchange my A800E against an A810 (e.g. an engineering sample?) or a smaller version with less ports if such a card exists. Could you please advise on how to possibly proceed with that? In return I would also offer to provide a write-up of a "how-to document" for using the A810 in a guest vm under linux KVM.

Thanks and regards Atom2

i] Last edited by Atom2 at 2012-5-30 17:40 [/i