Re: [Xen-devel] [PATCH] x86/iommu: remove usage of {set/clear}_identity_p2m_entry against PV domains

[Paul Durrant <Paul.Durrant@xxxxxxxxxx>]

> -----Original Message-----
> From: Roger Pau Monne <roger.pau@xxxxxxxxxx>
> Sent: 02 August 2019 10:22
> To: xen-devel@xxxxxxxxxxxxxxxxxxxx
> Cc: Roger Pau Monne <roger.pau@xxxxxxxxxx>; Roman Shaposhnik 
> <roman@xxxxxxxxxx>; George Dunlap
> <George.Dunlap@xxxxxxxxxx>; Jan Beulich <jbeulich@xxxxxxxx>; Andrew Cooper
> <Andrew.Cooper3@xxxxxxxxxx>; Wei Liu <wl@xxxxxxx>; Kevin Tian 
> <kevin.tian@xxxxxxxxx>; Paul Durrant
> <Paul.Durrant@xxxxxxxxxx>
> Subject: [PATCH] x86/iommu: remove usage of {set/clear}_identity_p2m_entry 
> against PV domains
> 
> Switch rmrr_identity_mapping to use iommu_{un}map in order to
> establish RMRR mappings for PV domains, like it's done in
> arch_iommu_hwdom_init. This solves the issue of a PV hardware domain
> not getting RMRR mappings because {set/clear}_identity_p2m_entry was
> not properly updating the iommu page tables.
> 

I'm not sure this is the right approach. TBH it's not clear to me exactly what 
role the P2M code should play for a PV domain (I'm guessing it's probably there 
so that shadowing can be turned on) but it would make more sense to me if fewer 
paths went round the side of it and the internals handled all of the PV/HVM 
differences.

  Paul
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel