Messages in this thread | | | Date | Mon, 15 Apr 2019 14:37:11 -0600 | From | Alex Williamson <> | Subject | Re: [PATCH 10/18] iommu/vt-d: Add custom allocator for IOASID |
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On Mon, 8 Apr 2019 16:59:25 -0700 Jacob Pan <jacob.jun.pan@linux.intel.com> wrote:
> When VT-d driver runs in the guest, PASID allocation must be > performed via virtual command interface. This patch register a > custom IOASID allocator which takes precedence over the default > IDR based allocator. The resulting IOASID allocation will always > come from the host. This ensures that PASID namespace is system- > wide. > > Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> > Signed-off-by: Liu, Yi L <yi.l.liu@intel.com> > Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com> > --- > drivers/iommu/intel-iommu.c | 50 +++++++++++++++++++++++++++++++++++++++++++++ > include/linux/intel-iommu.h | 1 + > 2 files changed, 51 insertions(+) > > diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c > index 28cb713..a38d774 100644 > --- a/drivers/iommu/intel-iommu.c > +++ b/drivers/iommu/intel-iommu.c > @@ -4820,6 +4820,42 @@ static int __init platform_optin_force_iommu(void) > return 1; > } > > +static ioasid_t intel_ioasid_alloc(ioasid_t min, ioasid_t max, void *data) > +{ > + struct intel_iommu *iommu = data; > + ioasid_t ioasid; > + > + if (vcmd_alloc_pasid(iommu, &ioasid)) > + return INVALID_IOASID; > + return ioasid;
How does this honor min/max?
> +} > + > +static int intel_ioasid_free(ioasid_t ioasid, void *data) > +{ > + struct iommu_pasid_alloc_info *svm; > + struct intel_iommu *iommu = data; > + > + if (!iommu || !cap_caching_mode(iommu->cap)) > + return -EINVAL; > + /* > + * Sanity check the ioasid owner is done at upper layer, e.g. VFIO > + * We can only free the PASID when all the devices are unbond. > + */ > + svm = ioasid_find(NULL, ioasid, NULL); > + if (!svm) { > + pr_warn("Freeing unbond IOASID %d\n", ioasid); > + return -EBUSY; > + } > + vcmd_free_pasid(iommu, ioasid); > + > + return 0; > +} > + > +static struct ioasid_allocator intel_iommu_ioasid_allocator = { > + .alloc = intel_ioasid_alloc, > + .free = intel_ioasid_free, > +}; > + > int __init intel_iommu_init(void) > { > int ret = -ENODEV; > @@ -4921,6 +4957,20 @@ int __init intel_iommu_init(void) > "%s", iommu->name); > iommu_device_set_ops(&iommu->iommu, &intel_iommu_ops); > iommu_device_register(&iommu->iommu); > + if (cap_caching_mode(iommu->cap) && sm_supported(iommu)) { > + /* > + * Register a custom ASID allocator if we are running > + * in a guest, the purpose is to have a system wide PASID > + * namespace among all PASID users. > + * Note that only one vIOMMU in each guest is supported.
Why one vIOMMU per guest? This would prevent guests with multiple PCI domains aiui.
> + */ > + intel_iommu_ioasid_allocator.pdata = (void *)iommu; > + ret = ioasid_set_allocator(&intel_iommu_ioasid_allocator); > + if (ret == -EBUSY) { > + pr_info("Custom IOASID allocator already registered\n"); > + break; > + } > + } > } > > bus_set_iommu(&pci_bus_type, &intel_iommu_ops); > diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h > index b29c85c..bc09d80 100644 > --- a/include/linux/intel-iommu.h > +++ b/include/linux/intel-iommu.h > @@ -31,6 +31,7 @@ > #include <linux/iommu.h> > #include <linux/io-64-nonatomic-lo-hi.h> > #include <linux/dmar.h> > +#include <linux/ioasid.h> > > #include <asm/cacheflush.h> > #include <asm/iommu.h>
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