Messages in this thread Patch in this message | | | From | Jacob Pan <> | Subject | [PATCH 10/18] iommu/vt-d: Add custom allocator for IOASID | Date | Mon, 8 Apr 2019 16:59:25 -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 | 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; +} + +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. + */ + 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> -- 2.7.4
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