On Fri, Sep 25, 2020 at 01:26:29PM +0200, Jean-Philippe Brucker wrote: > On Fri, Sep 25, 2020 at 06:22:57AM -0400, Michael S. Tsirkin wrote: > > On Fri, Sep 25, 2020 at 10:48:06AM +0200, Jean-Philippe Brucker wrote: > > > On Fri, Aug 21, 2020 at 03:15:34PM +0200, Jean-Philippe Brucker wrote: > > > > Add a topology description to the virtio-iommu driver and enable x86 > > > > platforms. > > > > > > > > Since [v2] we have made some progress on adding ACPI support for > > > > virtio-iommu, which is the preferred boot method on x86. It will be a > > > > new vendor-agnostic table describing para-virtual topologies in a > > > > minimal format. However some platforms don't use either ACPI or DT for > > > > booting (for example microvm), and will need the alternative topology > > > > description method proposed here. In addition, since the process to get > > > > a new ACPI table will take a long time, this provides a boot method even > > > > to ACPI-based platforms, if only temporarily for testing and > > > > development. > > > > > > > > v3: > > > > * Add patch 1 that moves virtio-iommu to a subfolder. > > > > * Split the rest: > > > > * Patch 2 adds topology-helper.c, which will be shared with the ACPI > > > > support. > > > > * Patch 4 adds definitions. > > > > * Patch 5 adds parser in topology.c. > > > > * Address other comments. > > > > > > > > Linux and QEMU patches available at: > > > > https://jpbrucker.net/git/linux virtio-iommu/devel > > > > https://jpbrucker.net/git/qemu virtio-iommu/devel > > > > > > I'm parking this work again, until we make progress on the ACPI table, or > > > until a platform without ACPI and DT needs it. Until then, I've pushed v4 > > > to my virtio-iommu/topo branch and will keep it rebased on master. > > > > > > Thanks, > > > Jean > > > > I think you guys need to work on virtio spec too, not too much left to > > do there ... > > I know it's ready and I'd really like to move on with this, but I'd rather > not commit it to the spec until we know it's going to be used at all. As > Gerd pointed out the one example we had, microvm, now supports ACPI. Since > we've kicked off the ACPI work anyway it isn't clear that the built-in > topology will be useful. > > Thanks, > Jean Many power platforms are OF based, thus without ACPI or DT support. -- MST
