> -----Original Message----- > From: Auger Eric <eric.au...@redhat.com> > Sent: 02 October 2020 14:56 > To: Thanos Makatos <thanos.maka...@nutanix.com>; vfio- > us...@redhat.com > Cc: John G Johnson <john.g.john...@oracle.com> > Subject: Re: [vfio-users] location of regions > VFIO_REGION_TYPE_MIGRATION/VFIO_REGION_SUBTYPE_MIGRATION > > Hi Thanos, > > On 10/2/20 2:54 PM, Thanos Makatos wrote: > > According to linux/include/uapi/linux/vfio.h, for a device to support > migration > > it must provide a VFIO capability of type VFIO_REGION_INFO_CAP_TYPE > and set > > .type/.subtype to > VFIO_REGION_TYPE_MIGRATION/VFIO_REGION_TYPE_MIGRATION. > > > > What confuses me is the following: > > > > "The structure vfio_device_migration_info is placed at the 0th offset of > > the VFIO_REGION_SUBTYPE_MIGRATION region to get and set VFIO > device related > > migration information." > > > > Where do regions VFIO_REGION_TYPE_MIGRATION and > VFIO_REGION_SUBTYPE_MIGRATION > > live on the device's address space? Is just like any other region, except > > that > > in the case of a PCI device it's index must be equal to, or larger than, > > VFIO_PCI_NUM_REGIONS, and set arbitrarily by the device > implementation? If > > so, then I suppose this index must appear in struct > vfio_device_info.num_regions? > > You need to call VFIO_DEVICE_GET_REGION_INFO with the region > type/subtype. The index of the region is stored in struct > vfio_region_info index.
Are you talking from perspective of the user or the driver? I want to know how to support migration in the driver. VFIO_DEVICE_GET_REGION_INFO doesn't take a type/subtype argument, it only takes the region index and the driver fills in the rest of the information. _______________________________________________ vfio-users mailing list vfio-users@redhat.com https://www.redhat.com/mailman/listinfo/vfio-users
