Re: [Xen-devel] [PATCH 1/1] keep iommu disabled until iommu_setup is called

[Ronny Hegewald <ronny.hegewald@xxxxxxxxx>]

> The concept is plausible, but I'm not convinced that there aren't
> any users of iommu_enabled that actually depend on it having
> its final value after command line parsing, yet before
> iommu_setup() gets called. 

But that is currently only true for systems with a iommu. For the ones without 
one have iommu_enabled=1 first, until iommu_setup() is called and 
iommu_enabled is set to 0 because of the not detectable iommu.

So, with or without my patch, a similiar problem seems to be present, just for 
different systems.

> Did you fully audit all users?

No, because there is just no way i can make a meaningfull judgement how the 
iommu code interdepends with all the other parts that check iommu_enabled. 

> As to the patch itself, ...

I will send a 2. version which addresses your comments as soon its clear if 
the approach in the patch is the right one to fix the crash.


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