On 19-03-01 15:07:34, Peter Xu wrote: > On Thu, Feb 28, 2019 at 09:47:54PM +0800, Yi Sun wrote: > > Intel vt-d rev3.0 [1] introduces a new translation mode called > > 'scalable mode', which enables PASID-granular translations for > > first level, second level, nested and pass-through modes. The > > vt-d scalable mode is the key ingredient to enable Scalable I/O > > Virtualization (Scalable IOV) [2] [3], which allows sharing a > > device in minimal possible granularity (ADI - Assignable Device > > Interface). As a result, previous Extended Context (ECS) mode > > is deprecated (no production ever implements ECS). > > > > This patch set emulates a minimal capability set of VT-d scalable > > mode, equivalent to what is available in VT-d legacy mode today: > > 1. Scalable mode root entry, context entry and PASID table > > 2. Seconds level translation under scalable mode > > 3. Queued invalidation (with 256 bits descriptor) > > 4. Pass-through mode > > > > Corresponding intel-iommu driver support will be included in > > kernel 5.0: > > https://www.spinics.net/lists/kernel/msg2985279.html > > > > We will add emulation of full scalable mode capability along with > > guest iommu driver progress later, e.g.: > > 1. First level translation > > 2. Nested translation > > 3. Per-PASID invalidation descriptors > > 4. Page request services for handling recoverable faults > > > > To verify the patches, below cases were tested according to Peter Xu's > > suggestions. > > > > +---------+----------------------------------------------------------------+----------------------------------------------------------------+ > > | | w/ Device Passthr > > | w/o Device Passthr | > > | > > +-------------------------------+--------------------------------+-------------------------------+--------------------------------+ > > | | virtio-net-pci, vhost=on | virtio-net-pci, vhost=off > > | virtio-net-pci, vhost=on | virtio-net-pci, vhost=off | > > | > > +-------------------------------+--------------------------------+-------------------------------+--------------------------------+ > > | | netperf | kernel bld | data cp| netperf | kernel bld | data > > cp | netperf | kernel bld | data cp| netperf | kernel bld | data cp | > > > > +---------+-------------------------------+--------------------------------+-------------------------------+--------------------------------+ > > | Legacy | Pass | Pass | Pass | Pass | Pass | Pass > > | Pass | Pass | Pass | Pass | Pass | Pass | > > > > +---------+-------------------------------+--------------------------------+-------------------------------+--------------------------------+ > > | Scalable| Pass | Pass | Pass | Pass | Pass | Pass > > | Pass | Pass | Pass | Pass | Pass | Pass | > > > > +---------+-------------------------------+--------------------------------+-------------------------------+--------------------------------+ > > Hi, Yi, > > Thanks very much for the thorough test matrix! > Thanks for the review and comments! :)
> The last thing I'd like to confirm is have you tested device > assignment with v2? And note that when you test with virtio devices Yes, I tested a MDEV assignment which can walk the Scalable Mode patches flows (both kernel and qemu). > you should not need caching-mode=on (but caching-mode=on should not > break anyone though). > For virtio-net-pci without device assignment, I did not use "caching-mode=on". > I've still got some comments here and there but it looks very good at > least to me overall. > > Thanks, > > -- > Peter Xu
