From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joerg Roedel Subject: Re: [PATCH 1/1] iommu: Bind process address spaces to devices Date: Tue, 26 Feb 2019 12:17:43 +0100 Message-ID: <20190226111743.GK20740@8bytes.org> References: <20190220142759.33308-1-jean-philippe.brucker@arm.com> <20190220142759.33308-2-jean-philippe.brucker@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20190220142759.33308-2-jean-philippe.brucker@arm.com> Sender: linux-kernel-owner@vger.kernel.org To: Jean-Philippe Brucker Cc: iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, christian.koenig@amd.com, kevin.tian@intel.com, jacob.jun.pan@linux.intel.com, ashok.raj@intel.com, baolu.lu@linux.intel.com, alex.williamson@redhat.com List-Id: iommu@lists.linux-foundation.org Hi Jean-Philippe, Thanks for the patch! I think this is getting close to be applied after the next merge window. On Wed, Feb 20, 2019 at 02:27:59PM +0000, Jean-Philippe Brucker wrote: > +int iommu_sva_bind_device(struct device *dev, struct mm_struct *mm, int *pasid, > + iommu_mm_exit_handler_t mm_exit, void *drvdata) I think we are better of with introducing a sva-bind handle which can be used to extend and further configure the binding done with this function. How about a 'struct iommu_sva' with an iommu-private definition that is returned by this function: struct iommu_sva *iommu_sva_bind_device(struct device *dev, struct mm_struct *mm); and the corresponding unbind function: int iommu_sva_unbind_device(struct iommu_sva* *handle); (Btw, does this need to return and int? Can unbinding fail?). With that in place we can implement and extentable API base on the handle: int iommu_sva_get_pasid(struct iommu_sva *handle); void iommu_sva_set_exit_handler(struct iommu_sva *handle, iommu_mm_exit_handler_t mm_exit); I think at least the AMD IOMMU driver needs more call-backs like a handler that is invoked when a fault can not be resolved. And there might be others in the future, putting them all in the parameter list of the bind function doesn't scale well. Regards, Joerg