> -----Original Message----- > From: Yu, Zhang [mailto:yu.c.zh...@linux.intel.com] > Sent: 09 December 2014 10:11 > To: Paul Durrant; Keir (Xen.org); Tim (Xen.org); jbeul...@suse.com; Kevin > Tian; Xen-devel@lists.xen.org > Subject: One question about the hypercall to translate gfn to mfn. > > Hi all, > > As you can see, we are pushing our XenGT patches to the upstream. One > feature we need in xen is to translate guests' gfn to mfn in XenGT dom0 > device model. > > Here we may have 2 similar solutions: > 1> Paul told me(and thank you, Paul :)) that there used to be a > hypercall, XENMEM_translate_gpfn_list, which was removed by Keir in > commit 2d2f7977a052e655db6748be5dabf5a58f5c5e32, because there was > no > usage at that time. So solution 1 is to revert this commit. However, > since this hypercall was removed ages ago, the reverting met many > conflicts, i.e. the gmfn_to_mfn is no longer used in x86, etc. > > 2> In our project, we defined a new hypercall > XENMEM_get_mfn_from_pfn, which has a similar implementation like the > previous XENMEM_translate_gpfn_list. One of the major differences is > that this newly defined one is only for x86(called in arch_memory_op), > so we do not have to worry about the arm side. > > Does anyone has any suggestions about this?
IIUC what is needed is a means to IOMMU map a gfn in the service domain (dom0 for the moment) such that it can be accessed by the GPU. I think use of an raw mfn value currently works only because dom0 is using a 1:1 IOMMU mapping scheme. Is my understanding correct, or do you really need raw mfn values? Paul > Thanks in advance. :) > > B.R. > Yu _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
