Re: [Xen-devel] VT-d flush timeout

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 25.09.14 at 12:56, <andrew.cooper3@xxxxxxxxxx> wrote:
> On 25/09/14 11:55, Jan Beulich wrote:
>>>>> On 25.09.14 at 12:44, <andrew.cooper3@xxxxxxxxxx> wrote:
>>> The AMD code will wait for a period of time for the COMMAND_WAIT to
>>> start, but not panic() on a timeout.
>>>
>>> By my reading of the code, amd_iommu_flush_iotlb() can complete without
>>> confirming that the iotlbs have actually been flushed, and all that is
>>> left behind is an AMD_IOMMU_DEBUG() message.
>> Now that you say this I recall having stumbled across this questionable
>> behavior in the past (and perhaps even more than once). Certainly
>> something for our AMD IOMMU maintainers to look into...
> 
> Agreed, although for now I think it is safer to leave ATS disabled.

Fully agree.

Jan


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel