On Wed, Feb 02, 2022 at 04:10:06PM +0000, Shameerali Kolothum Thodi wrote: > > > > From: Jason Gunthorpe [mailto:jgg@xxxxxxxxxx] > > Sent: 02 February 2022 15:40 > > To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@xxxxxxxxxx> > > Cc: kvm@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; > > linux-crypto@xxxxxxxxxxxxxxx; alex.williamson@xxxxxxxxxx; > > mgurtovoy@xxxxxxxxxx; Linuxarm <linuxarm@xxxxxxxxxx>; liulongfang > > <liulongfang@xxxxxxxxxx>; Zengtao (B) <prime.zeng@xxxxxxxxxxxxx>; > > yuzenghui <yuzenghui@xxxxxxxxxx>; Jonathan Cameron > > <jonathan.cameron@xxxxxxxxxx>; Wangzhou (B) <wangzhou1@xxxxxxxxxxxxx> > > Subject: Re: [RFC v2 0/4] vfio/hisilicon: add acc live migration driver > > > > On Wed, Feb 02, 2022 at 02:34:52PM +0000, Shameerali Kolothum Thodi > > wrote: > > > > > > There are few topics to consider: > > > > - Which of the three feature sets (STOP_COPY, P2P and PRECOPY) make > > > > sense for this driver? > > > > > > I think it will be STOP_COPY only for now. We might have PRECOPY > > > feature once we have the SMMUv3 HTTU support in future. > > > > HTTU is the dirty tracking feature? To be clear VFIO migration support for > > PRECOPY has nothing to do with IOMMU based dirty page tracking. > > Yes, it is based on the IOMMU hardware dirty bit management support. > A RFC was posted sometime back, > https://lore.kernel.org/kvm/20210507103608.39440-1-zhukeqian1@xxxxxxxxxx/ Yes, I saw that. I was hoping to have a discussion on this soon about how to integrate that with the iommufd work, which I hope will allow that series, and the other IOMMU drivers that can support this to be merged.. Jason
