Hi Kevin, On Fri, 18 Mar 2022 05:33:38 +0000, "Tian, Kevin" <[email protected]> wrote:
> > From: Jacob Pan > > Sent: Thursday, March 17, 2022 5:02 AM > > > > Hi Kevin, > > > > On Wed, 16 Mar 2022 07:41:34 +0000, "Tian, Kevin" <[email protected]> > > wrote: > > > > > > From: Jason Gunthorpe <[email protected]> > > > > Sent: Tuesday, March 15, 2022 10:33 PM > > > > > > > > On Mon, Mar 14, 2022 at 10:07:07PM -0700, Jacob Pan wrote: > > > > > + /* > > > > > + * Each domain could have multiple devices attached with > > > > > shared or > > > > per > > > > > + * device PASIDs. At the domain level, we keep track of > > > > > unique PASIDs > > > > and > > > > > + * device user count. > > > > > + * E.g. If a domain has two devices attached, device A > > > > > has PASID 0, 1; > > > > > + * device B has PASID 0, 2. Then the domain would have > > > > > PASID 0, 1, 2. > > > > > + */ > > > > > > > > A 2d array of xarray's seems like a poor data structure for this > > > > task. > > > > > Perhaps i mis-presented here, I am not using 2D array. It is an 1D > > xarray for domain PASIDs only. Then I use the existing device list in > > each domain, adding another xa to track per-device-domain PASIDs. > > > besides that it also doesn't work when we support per-device PASID > > > allocation in the future. In that case merging device PASIDs together > > > is conceptually wrong. > > > > > Sorry, could you elaborate? If we do per-dev PASID allocation, we could > > use the ioasid_set for each pdev, right? > > My point is simply about the comment above which says the domain > will have PASID 0, 1, 2 when there is [devA, PASID0] and [devB, PASID0]. > You can maintain a single PASID list only when it's globally allocated > cross devices. otherwise this has to be a tuple including device and > PASID. > Got you, you are right we don't want to limit to globally allocated scheme. Thanks, Jacob _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
