On Fri, Dec 06, 2019 at 07:55:15AM +0800, Alex Williamson wrote: > On Wed, 4 Dec 2019 22:26:38 -0500 > Yan Zhao <yan.y.zhao@xxxxxxxxx> wrote: > > > Vendor driver specifies when to support a migration region through cap > > VFIO_PCI_DEVICE_CAP_MIGRATION in vfio_pci_mediate_ops->open(). > > > > If vfio-pci detects this cap, it creates a default migration region on > > behalf of vendor driver with region len=0 and region->ops=null. > > Vendor driver should override this region's len, flags, rw, mmap in > > its vfio_pci_mediate_ops. > > > > This migration region definition is aligned to QEMU vfio migration code v8: > > (https://lists.gnu.org/archive/html/qemu-devel/2019-08/msg05542.html) > > > > Cc: Kevin Tian <kevin.tian@xxxxxxxxx> > > > > Signed-off-by: Yan Zhao <yan.y.zhao@xxxxxxxxx> > > --- > > drivers/vfio/pci/vfio_pci.c | 15 ++++ > > include/linux/vfio.h | 1 + > > include/uapi/linux/vfio.h | 149 ++++++++++++++++++++++++++++++++++++ > > 3 files changed, 165 insertions(+) > > > > diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c > > index f3730252ee82..059660328be2 100644 > > --- a/drivers/vfio/pci/vfio_pci.c > > +++ b/drivers/vfio/pci/vfio_pci.c > > @@ -115,6 +115,18 @@ static inline bool vfio_pci_is_vga(struct pci_dev *pdev) > > return (pdev->class >> 8) == PCI_CLASS_DISPLAY_VGA; > > } > > > > +/** > > + * init a region to hold migration ctl & data > > + */ > > +void init_migration_region(struct vfio_pci_device *vdev) > > +{ > > + vfio_pci_register_dev_region(vdev, VFIO_REGION_TYPE_MIGRATION, > > + VFIO_REGION_SUBTYPE_MIGRATION, > > + NULL, 0, > > + VFIO_REGION_INFO_FLAG_READ | VFIO_REGION_INFO_FLAG_WRITE, > > + NULL); > > +} > > + > > static void vfio_pci_probe_mmaps(struct vfio_pci_device *vdev) > > { > > struct resource *res; > > @@ -523,6 +535,9 @@ static int vfio_pci_open(void *device_data) > > vdev->mediate_ops = mentry->ops; > > vdev->mediate_handle = handle; > > > > + if (caps & VFIO_PCI_DEVICE_CAP_MIGRATION) > > + init_migration_region(vdev); > > No. We're not going to add a cap flag for every region the mediation > driver wants to add. The mediation driver should have the ability to > add regions and irqs to the device itself. Thanks, > > Alex > ok. got it. will do it. Thanks Yan > > + > > pr_info("vfio pci found mediate_ops %s, caps=%llx, handle=%x for %x:%x\n", > > vdev->mediate_ops->name, caps, > > handle, vdev->pdev->vendor, >
