On Fri, Sep 27, 2019 at 03:14:42PM +0800, Jason Wang wrote: > On 2019/9/27 下午12:54, Tiwei Bie wrote: > > > > + > > > > + /* > > > > + * In vhost-mdev, userspace should pass ring addresses > > > > + * in guest physical addresses when IOMMU is disabled or > > > > + * IOVAs when IOMMU is enabled. > > > > + */ > > > A question here, consider we're using noiommu mode. If guest physical > > > address is passed here, how can a device use that? > > > > > > I believe you meant "host physical address" here? And it also have the > > > implication that the HPA should be continuous (e.g using hugetlbfs). > > The comment is talking about the virtual IOMMU (i.e. iotlb in vhost). > > It should be rephrased to cover the noiommu case as well. Thanks for > > spotting this. > > > So the question still, if GPA is passed how can it be used by the > virtio-mdev device? Sorry if I didn't make it clear.. Of course, GPA can't be passed in noiommu mode. > > Thanks >
