> -----Original Message----- > From: iommu-bounces@xxxxxxxxxxxxxxxxxxxxxxxxxx [mailto:iommu- > bounces@xxxxxxxxxxxxxxxxxxxxxxxxxx] On Behalf Of Alex Williamson > Sent: Thursday, November 21, 2013 12:17 AM > To: Bhushan Bharat-R65777 > Cc: linux-pci@xxxxxxxxxxxxxxx; agraf@xxxxxxx; Yoder Stuart-B08248; Wood > Scott-B07421; iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx; bhelgaas@xxxxxxxxxx; > linuxppc-dev@xxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx > Subject: Re: [PATCH 0/9 v2] vfio-pci: add support for Freescale IOMMU > (PAMU) > > On Tue, 2013-11-19 at 10:47 +0530, Bharat Bhushan wrote: > > From: Bharat Bhushan <bharat.bhushan@xxxxxxxxxxxxx> > > > > PAMU (FSL IOMMU) has a concept of primary window and subwindows. > > Primary window corresponds to the complete guest iova address space > > (including MSI space), with respect to IOMMU_API this is termed as > > geometry. IOVA Base of subwindow is determined from the number of > > subwindows (configurable using iommu API). > > MSI I/O page must be within the geometry and maximum supported > > subwindows, so MSI IO-page is setup just after guest memory iova space. > > > > So patch 1/9-4/9(inclusive) are for defining the interface to get: > > - Number of MSI regions (which is number of MSI banks for powerpc) > > - MSI-region address range: Physical page which have the > > address/addresses used for generating MSI interrupt > > and size of the page. > > > > Patch 5/9-7/9(inclusive) is defining the interface of setting up MSI > > iova-base for a msi region(bank) for a device. so that when > > msi-message will be composed then this configured iova will be used. > > Earlier we were using iommu interface for getting the configured iova > > which was not currect and Alex Williamson suggeested this type of > interface. > > > > patch 8/9 moves some common functions in a separate file so that these > > can be used by FSL_PAMU implementation (next patch uses this). > > These will be used later for iommu-none implementation. I believe we > > can do more of this but will take step by step. > > > > Finally last patch actually adds the support for FSL-PAMU :) > > Patches 1-3: msi_get_region needs to return an error an error (probably > -EINVAL) if called on a path where there's no backend implementation. > Otherwise the caller doesn't know that the data in the region pointer > isn't valid. > > Patches 5&6: same as above for msi_set_iova, return an error if no > backend implementation. > > Patch 7: Why does fsl_msi_del_iova_device bother to return anything if > it's always zero? Return -ENODEV when not found? > > Patch 9: > > vfio_handle_get_attr() passes random kernel data back to userspace in the > event of iommu_domain_get_attr() error. > > vfio_handle_set_attr(): I don't see any data validation happening, is > iommu_domain_set_attr() really that safe? [Sethi Varun-B16395] The parameter validation can be left to the lower level iommu driver. The attribute could be specific to a given hardware. -Varun -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
