Re: [Xen-devel] [PATCH 34/34] RFC x86: introduce directio virt cap

[Wei Liu <wei.liu2@xxxxxxxxxx>]

On Tue, Aug 21, 2018 at 10:32:18AM +0200, Roger Pau Monné wrote:
> On Fri, Aug 17, 2018 at 04:12:52PM +0100, Wei Liu wrote:
> > hvm_directio is set when iommu is enabled, but in fact iommu is not
> > tied to HVM. In order to not break existing tools, expose a new flag
> > directio for (iommu_enabled && !hvm_enabled).
> > 
> > RFC This doesn't build at the moment. Do we care about that flag being
> > inaccurate?
> 
> I think there is no hardware out there with an IOMMU that don't have
> virtualization extensions (ie: having VTd but not VTx for example),
> but maybe I'm wrong.

The question is whether it makes sense to expose the name "hvm_directio"
at all when you can't run an HVM guest in the first place.

Also iommu isn't an HVM only feature, PV guests can also make use of it
if I understand correctly, hence the suggestion of "directio".

Wei.

> 
> Roger.

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