On Sat, 2014-02-08 at 18:29 +0100, Antonios Motakis wrote: > This is a workaround to make the VFIO_IOMMU_TYPE1 driver usable with > platform devices instead of PCI. A future permanent fix should support > both. This is required in order to use the Exynos SMMU, or ARM SMMU > driver with VFIO. There are two separate things going on here, one is that platform devices need to allocate an iommu domain using the correct bus_type. I think this is better solved using something like this RFC (plus subsequent comments): http://lists.linuxfoundation.org/pipermail/iommu/2014-January/007459.html That way the vfio iommu backend can mix and match but_types across domains even within a container. The other thing is relaxing the interrupt remapping requirement. What's the justification for this? Are platform devices not susceptible? Could the iommu driver advertise interrupt remapping support if it's not an issue? Why do we need both allow_unsafe_interrupts and require_cap_intr_remap? > Signed-off-by: Antonios Motakis <a.motakis@xxxxxxxxxxxxxxxxxxxxxx> > --- > drivers/vfio/Kconfig | 2 +- > drivers/vfio/vfio_iommu_type1.c | 22 ++++++++++++++++++---- > 2 files changed, 19 insertions(+), 5 deletions(-) > > diff --git a/drivers/vfio/Kconfig b/drivers/vfio/Kconfig > index 26b3d9d..bd50721 100644 > --- a/drivers/vfio/Kconfig > +++ b/drivers/vfio/Kconfig > @@ -11,7 +11,7 @@ config VFIO_IOMMU_SPAPR_TCE > menuconfig VFIO > tristate "VFIO Non-Privileged userspace driver framework" > depends on IOMMU_API > - select VFIO_IOMMU_TYPE1 if X86 > + select VFIO_IOMMU_TYPE1 if X86 || ARM > select VFIO_IOMMU_SPAPR_TCE if (PPC_POWERNV || PPC_PSERIES) > help > VFIO provides a framework for secure userspace device drivers. > diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c > index ad7a1f6..81e65f4 100644 > --- a/drivers/vfio/vfio_iommu_type1.c > +++ b/drivers/vfio/vfio_iommu_type1.c > @@ -30,7 +30,8 @@ > #include <linux/iommu.h> > #include <linux/module.h> > #include <linux/mm.h> > -#include <linux/pci.h> /* pci_bus_type */ > +#include <linux/pci.h> /* pci_bus_type */ > +#include <linux/platform_device.h> /* platform_bus_type */ > #include <linux/rbtree.h> > #include <linux/sched.h> > #include <linux/slab.h> > @@ -47,6 +48,8 @@ module_param_named(allow_unsafe_interrupts, > allow_unsafe_interrupts, bool, S_IRUGO | S_IWUSR); > MODULE_PARM_DESC(allow_unsafe_interrupts, > "Enable VFIO IOMMU support for on platforms without interrupt remapping support."); > +static struct bus_type *iommu_bus_type = NULL; > +static bool require_cap_intr_remap = false; nit, unnecessary initialization. > > static bool disable_hugepages; > module_param_named(disable_hugepages, > @@ -785,7 +788,8 @@ static void *vfio_iommu_type1_open(unsigned long arg) > /* > * Wish we didn't have to know about bus_type here. > */ > - iommu->domain = iommu_domain_alloc(&pci_bus_type); > + iommu->domain = iommu_domain_alloc(iommu_bus_type); > + > if (!iommu->domain) { > kfree(iommu); > return ERR_PTR(-EIO); > @@ -797,7 +801,7 @@ static void *vfio_iommu_type1_open(unsigned long arg) > * the way. Fortunately we know interrupt remapping is global for > * our iommus. > */ > - if (!allow_unsafe_interrupts && > + if (require_cap_intr_remap && !allow_unsafe_interrupts && > !iommu_domain_has_cap(iommu->domain, IOMMU_CAP_INTR_REMAP)) { > pr_warn("%s: No interrupt remapping support. Use the module param \"allow_unsafe_interrupts\" to enable VFIO IOMMU support on this platform\n", > __func__); > @@ -914,7 +918,17 @@ static const struct vfio_iommu_driver_ops vfio_iommu_driver_ops_type1 = { > > static int __init vfio_iommu_type1_init(void) > { > - if (!iommu_present(&pci_bus_type)) > +#ifdef CONFIG_PCI > + if (iommu_present(&pci_bus_type)) { > + iommu_bus_type = &pci_bus_type; > + /* For PCI targets, IOMMU_CAP_INTR_REMAP is required */ > + require_cap_intr_remap = true; > + } > +#endif > + if (!iommu_bus_type && iommu_present(&platform_bus_type)) > + iommu_bus_type = &platform_bus_type; > + What if there are both? > + if(!iommu_bus_type) > return -ENODEV; > > return vfio_register_iommu_driver(&vfio_iommu_driver_ops_type1); Thanks, Alex _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/cucslists/listinfo/kvmarm
