Glad to see this bug report isn't completely dead. Can confirm too that the problem still exists with kernel 4.2.0-27-generic with the same motherboard as per the original bug report.
The attached is a recent extract from dmesg outputs...I use vfio passthrough for GFX on a Windows guest. You can see from the timestamps that I start the guest at 21:02:44 and at around 21:26:07 I get some DMAR faults pertain to device at 00:02.0. This device is the Intel IGD... lspci -s 00:02.0 00:02.0 VGA compatible controller: Intel Corporation Xeon E3-1200 v3/4th Gen Core Processor Integrated Graphics Controller (rev 06) ...not sure if this is related to the HDMI audio or not. What I can say is that I have to boot the host with "intel_iommu=on". If I change this to =on,igfx_off then my syslog fills with constant complaints about DMAR for another device I use in passthrough which works perfectly with =on, this device is a DVB-S2 device. If I use =igfx_off this stops IOMMU so I can not longer passthrough PCI devices but presto the HDMI audio now works?! ** Attachment added: "dmesg-extract-intel_iommu-on" https://bugs.launchpad.net/ubuntu/+source/alsa-driver/+bug/1428121/+attachment/4573164/+files/dmesg-extract-intel_iommu-on -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1428121 Title: Intel HDMI Audio not working with IOMMU enabled To manage notifications about this bug go to: https://bugs.launchpad.net/alsa-driver/+bug/1428121/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
