Messages in this thread Patch in this message | | | From | Jacob Pan <> | Subject | [PATCH v2 10/19] iommu/vt-d: Add custom allocator for IOASID | Date | Tue, 23 Apr 2019 16:31:10 -0700 |
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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 | 58 +++++++++++++++++++++++++++++++++++++++++++++ include/linux/intel-iommu.h | 2 ++ 2 files changed, 60 insertions(+)
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index d93c4bd..ec6f22d 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -1711,6 +1711,8 @@ static void free_dmar_iommu(struct intel_iommu *iommu) if (ecap_prs(iommu->ecap)) intel_svm_finish_prq(iommu); } + ioasid_unregister_allocator(&iommu->pasid_allocator); + #endif } @@ -4811,6 +4813,46 @@ 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; + + /* + * VT-d virtual command interface always uses the full 20 bit + * PASID range. Host can partition guest PASID range based on + * policies but it is out of guest's control. + */ + if (min < PASID_MIN || max > PASID_MAX) + return -EINVAL; + + if (vcmd_alloc_pasid(iommu, &ioasid)) + return INVALID_IOASID; + + return ioasid; +} + +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; +} + int __init intel_iommu_init(void) { int ret = -ENODEV; @@ -4912,6 +4954,22 @@ 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. + * There can be multiple vIOMMUs in each guest but only + * one allocator is active. All vIOMMU allocators will + * eventually be calling the same host allocator. + */ + iommu->pasid_allocator.alloc = intel_ioasid_alloc; + iommu->pasid_allocator.free = intel_ioasid_free; + iommu->pasid_allocator.pdata = (void *)iommu; + ret = ioasid_register_allocator(&iommu->pasid_allocator); + if (ret) + pr_warn("Custom PASID allocator registeration failed\n"); + } } bus_set_iommu(&pci_bus_type, &intel_iommu_ops); diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h index bff907b..c24c8aa 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> @@ -549,6 +550,7 @@ struct intel_iommu { #ifdef CONFIG_INTEL_IOMMU_SVM struct page_req_dsc *prq; unsigned char prq_name[16]; /* Name for PRQ interrupt */ + struct ioasid_allocator pasid_allocator; /* Custom allocator for PASIDs */ #endif struct q_inval *qi; /* Queued invalidation info */ u32 *iommu_state; /* Store iommu states between suspend and resume.*/ -- 2.7.4
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