> From: Alex Williamson <alex.williamson@xxxxxxxxxx> > Sent: Tuesday, July 19, 2022 6:30 AM > > On Thu, 14 Jul 2022 11:12:43 +0300 > Yishai Hadas <yishaih@xxxxxxxxxx> wrote: > > > DMA logging allows a device to internally record what DMAs the device is > > initiating and report them back to userspace. It is part of the VFIO > > migration infrastructure that allows implementing dirty page tracking > > during the pre copy phase of live migration. Only DMA WRITEs are logged, > > and this API is not connected to > VFIO_DEVICE_FEATURE_MIG_DEVICE_STATE. > > > > This patch introduces the DMA logging involved uAPIs. > > > > It uses the FEATURE ioctl with its GET/SET/PROBE options as of below. > > > > It exposes a PROBE option to detect if the device supports DMA logging. > > It exposes a SET option to start device DMA logging in given IOVAs > > ranges. > > It exposes a SET option to stop device DMA logging that was previously > > started. > > It exposes a GET option to read back and clear the device DMA log. > > > > Extra details exist as part of vfio.h per a specific option. > > > Kevin, Kirti, others, any comments on this uAPI proposal? Are there > potentially other devices that might make use of this or is everyone > else waiting for IOMMU based dirty tracking? > I plan to take a look later this week. >From Intel side I'm not aware of such device so far and IOMMU based dirty tracking would be the standard way to go.
