[Pkg-xen-devel] Problem with jessie kernel under xen w.r.t. mpt3sas and "swiotlb buffer is full"

[Andy Smith]

Hi,

As reported here:

    https://lists.xen.org/archives/html/xen-devel/2016-12/msg00287.html

The current Debian jessie amd64 kernel is unusable as a Xen dom0 on
a server that uses the mpt3sas driver as it panics within a
few seconds of heavy IO load, complaining "swiotlb is full"

The response from Andrew Cooper linked to two patches:

    https://lists.xen.org/archives/html/xen-devel/2016-12/msg00294.html

    > Can you try these two patches from the XenServer Patch queue?
    > https://github.com/xenserver/linux-3.x.pg/blob/master/master/series#L613-L614
    > 
    > There are bugs with some device drivers in choosing the correct
    > DMA mask, which cause them incorrectly to believe that they need
    > bounce-buffering.  Once you hit bounce buffering, everything
    > grinds to a halt.

Those two patches do fix the problem for me.

Does the current testing kernel already include these patches?

Should this be reported as a bug against the kernel in jessie?

Presumably the jessie kernel is not now going to see a fix for this
so would it be useful to have it in the bts in case other jessie
users come across it?

Cheers,
Andy