On Fri, 25 May 2018 08:44:05 +0000 "Wuzongyong (Euler Dept)" <cordius...@huawei.com> wrote:
> Hi, > > I noted that the comments in vfio_iommu_type1_attach_group: > /* > * Try to match an existing compatible domain. We don't want > to > * preclude an IOMMU driver supporting multiple bus_types and > being > * able to include different bus_types in the same IOMMU > domain, so > * we test whether the domains use the same iommu_ops rather > than > * testing if they're on the same bus_type. > */ > > In intel x86 platforms currently, can I think a virtual machine have a > one-to-one association with a vfio container, > and a vfio container have a one-to-one association with a iommu_domain?. Until we start adding vIOMMUs to the VM configuration, yes, all assigned devices for a VM instance are typically within a single container which usually has a 1:1 association to an iommu_domain. A vfio container represents a single IOMMU context, so as long as all the devices in the VM can only exists in a single address space within that VM, they're in the same container. A vIOMMU introduces a per-device address space within the VM. > Does there exist any scene or system that two domains use two different > iommu_ops? It is possible, but largely theoretical for x86. It's possible if you look at vfio-platform in combination with vfio-pci, which is more likely to be seen on ARM platforms. Thanks, Alex _______________________________________________ vfio-users mailing list vfio-users@redhat.com https://www.redhat.com/mailman/listinfo/vfio-users
