Re: [Xen-devel] Xen-unstable-staging: Xen BUG at iommu_map.c:455

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 21.04.15 at 10:24, <linux@xxxxxxxxxxxxxx> wrote:
> Tuesday, April 21, 2015, 10:11:07 AM, you wrote:
>> Interesting - didn't you say that as a side effect of Andrew's patch
>> you saw massive log spam?
> 
> If you mean these:
> 
> (XEN) [2015-04-12 14:55:20.226] p2m.c:884:d0v0 gfn_to_mfn failed! 
> gfn=ffffffff001ed type:4
> [...]
> 
> Those were actually due to Konrad's kernel patch that was on the devel-4.1 
> branch that has already been dropped. 
> (commit 22d8a8938407cb1342af763e937fdf9ee8daf24a
>  'xen/pciback: Don't disable PCI_COMMAND on PCI device reset.')

Ah, okay. Iirc there was no progress towards a resolution there yet?

> For the rest there is some extra log spam now, since the memory maps now are 
> done 
> in very small chunks (the hypercall continuation stuff working?):
> (XEN) [2015-04-21 08:04:01.207] memory_map:add: dom20 gfn=ec780 mfn=cc780 
> nr=40
> [...]
> Don't know if that makes much sense anymore (unless specifically enabled if 
> you 
> want such detail .. and the whole range with perhaps a start and finish 
> message 
> is not enough)

The hypervisor can't really tell whether a re-invocation of said
hypercall is a continuation or a new request. Hence we can only
either drop the message altogether or live with it being spammy
on large regions (it's a XENLOG_G_INFO one anyway, so not
enabled by default, and if enabled usually rate limited).

Jan


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