Dom0 kernel panic

Hi,

We're experiencing some major issues with our newly build xenserver 7.0 enviroment.

The xenservers are hosting PVS streamed VDI's.which are powercontrolled by Xendesktop.

When the xenserver are running for a while and a poweraction is performed on multiple VDI's (from xencenter or studio) the server becomes unresponsive and will crash. Dell system logs return the following error:
Critical Interrupt #0x19 | PCI PERR (PCI PERR |PCI bus:00 device:05 function:2) | Asserted
Unknown #0x1a | | Asserted
Critical Interrupt #0x19 | PCI PERR (PCI PERR |PCI bus:00 device:05 function:0) | Asserted

We are experiencing this issue on al the servers. Dell has replaced the mainboard and the CPU's for 2 servers but this didn't help.

dom0.log shows: EMERG: BUG: soft lockup - CPU#0 stuck for 21s!