> From: Kenneth Lee > Sent: Thursday, August 2, 2018 11:40 AM > > On Thu, Aug 02, 2018 at 02:59:33AM +0000, Tian, Kevin wrote: > > > From: Kenneth Lee > > > Sent: Wednesday, August 1, 2018 6:22 PM > > > > > > From: Kenneth Lee <liguozhu@xxxxxxxxxxxxx> > > > > > > WarpDrive is an accelerator framework to expose the hardware > capabilities > > > directly to the user space. It makes use of the exist vfio and vfio-mdev > > > facilities. So the user application can send request and DMA to the > > > hardware without interaction with the kernel. This remove the latency > > > of syscall and context switch. > > > > > > The patchset contains documents for the detail. Please refer to it for > more > > > information. > > > > > > This patchset is intended to be used with Jean Philippe Brucker's SVA > > > patch [1] (Which is also in RFC stage). But it is not mandatory. This > > > patchset is tested in the latest mainline kernel without the SVA patches. > > > So it support only one process for each accelerator. > > > > If no sharing, then why not just assigning the whole parent device to > > the process? IMO if SVA usage is the clear goal of your series, it > > might be made clearly so then Jean's series is mandatory dependency... > > > > We don't know how SVA will be finally. But the feature, "make use of > per-PASID/substream ID IOMMU page table", should be able to be enabled > in the > kernel. So we don't want to enforce it here. After we have this serial ready, > it > can be hooked to any implementation. "any" or "only queue-based" implementation? some devices may not have queue concept, e.g. GPU. > > Further more, even without "per-PASID IOMMU page table", this series has > its > value. It is not simply dedicate the whole device to the process. It "shares" > the device with the kernel driver. So you can support crypto and a user > application at the same time. OK. Thanks Kevin
