On 18/07/16 04:29, Andrey Grodzovsky wrote: > > > On Fri, Jul 15, 2016 at 11:45 PM, Andrey Grodzovsky > <andrey2...@gmail.com <mailto:andrey2...@gmail.com>> wrote: > > > > On Fri, Jul 15, 2016 at 6:04 AM, Andrew Cooper > <andrew.coop...@citrix.com <mailto:andrew.coop...@citrix.com>> wrote: > > On 12/07/16 04:59, Andrey Grodzovsky wrote: >> Hello >> >> Some background - >> >> We are trying to run Qualcomm Atheros AR928X Wireless Network >> Adapter and have a crash right on driver load, following are >> our observations and questions. >> >> Jurgen's observation - >> >> " The Atheros card "Qualcomm Atheros AR928X Wireless Network >> Adapter (PCI-Express) (rev 01)" is plugged into the host >> system (datatron). >> When I attach it to the DomU - the module "ath9k" is >> automatically loaded, but it gives an exception >> "iowrite32+0x2b/0x30". >> No idea what the issue is (tried also with another Atheros >> Card (ath10k) - similar problem). When I try an Intel card, >> it works. >> (the card also works on the Dom0 - so the Linux driver and HW >> is OK)." >> >> Debugging - >> >> After some investigation with kgdb and iommu trace on DomU it >> seems the iomap of PCI BAR for the device returns a a mapping >> f which first 0x1000 bytes are read only and that causes >> access violation when trying to write registers mapped to >> this area (all the regs with offset < 0x1000) - why this >> happens i still don't know. Register writes with offsets > >> 0x1000 are fine. >
Your card is not PCI spec compliant. The Spec mandates that nothing may exist in any 4k aligned block covering part of the MSI-X table, precisely so read-only tricks like this can be done trap&intercept MSI-X updates. >> >> Running same driver on Dom0 is totally fine > This is curious. Dom0 and DomU should be treated identically in this regard. ~Andrew
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