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Message-Id: <1571946904-86776-4-git-send-email-jacob.jun.pan@linux.intel.com>
Date: Thu, 24 Oct 2019 12:54:56 -0700
From: Jacob Pan <jacob.jun.pan@...ux.intel.com>
To: iommu@...ts.linux-foundation.org,
LKML <linux-kernel@...r.kernel.org>,
Joerg Roedel <joro@...tes.org>,
David Woodhouse <dwmw2@...radead.org>,
Alex Williamson <alex.williamson@...hat.com>,
Jean-Philippe Brucker <jean-philippe@...aro.com>
Cc: "Yi Liu" <yi.l.liu@...el.com>,
"Tian, Kevin" <kevin.tian@...el.com>,
Raj Ashok <ashok.raj@...el.com>,
"Christoph Hellwig" <hch@...radead.org>,
"Lu Baolu" <baolu.lu@...ux.intel.com>,
Jonathan Cameron <jic23@...nel.org>,
Eric Auger <eric.auger@...hat.com>,
Jacob Pan <jacob.jun.pan@...ux.intel.com>
Subject: [PATCH v7 03/11] iommu/vt-d: Add custom allocator for IOASID
When VT-d driver runs in the guest, PASID allocation must be
performed via virtual command interface. This patch registers a
custom IOASID allocator which takes precedence over the default
XArray 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@...ux.intel.com>
Signed-off-by: Liu, Yi L <yi.l.liu@...el.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@...ux.intel.com>
---
drivers/iommu/Kconfig | 1 +
drivers/iommu/intel-iommu.c | 67 +++++++++++++++++++++++++++++++++++++++++++++
include/linux/intel-iommu.h | 2 ++
3 files changed, 70 insertions(+)
diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index fd50ddffffbf..961fe5795a90 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -211,6 +211,7 @@ config INTEL_IOMMU_SVM
bool "Support for Shared Virtual Memory with Intel IOMMU"
depends on INTEL_IOMMU && X86
select PCI_PASID
+ select IOASID
select MMU_NOTIFIER
help
Shared Virtual Memory (SVM) provides a facility for devices
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 3f974919d3bd..ced1d89ef977 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -1706,6 +1706,9 @@ static void free_dmar_iommu(struct intel_iommu *iommu)
if (ecap_prs(iommu->ecap))
intel_svm_finish_prq(iommu);
}
+ if (ecap_vcs(iommu->ecap) && vccap_pasid(iommu->vccap))
+ ioasid_unregister_allocator(&iommu->pasid_allocator);
+
#endif
}
@@ -4910,6 +4913,44 @@ static int __init probe_acpi_namespace_devices(void)
return 0;
}
+#ifdef CONFIG_INTEL_IOMMU_SVM
+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 > intel_pasid_max_id)
+ return INVALID_IOASID;
+
+ if (vcmd_alloc_pasid(iommu, &ioasid))
+ return INVALID_IOASID;
+
+ return ioasid;
+}
+
+static void intel_ioasid_free(ioasid_t ioasid, void *data)
+{
+ struct intel_iommu *iommu = data;
+
+ if (!iommu)
+ return;
+ /*
+ * 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.
+ */
+ if (ioasid_find(NULL, ioasid, NULL)) {
+ pr_alert("Cannot free active IOASID %d\n", ioasid);
+ return;
+ }
+ vcmd_free_pasid(iommu, ioasid);
+}
+#endif
+
int __init intel_iommu_init(void)
{
int ret = -ENODEV;
@@ -5020,6 +5061,32 @@ int __init intel_iommu_init(void)
"%s", iommu->name);
iommu_device_set_ops(&iommu->iommu, &intel_iommu_ops);
iommu_device_register(&iommu->iommu);
+#ifdef CONFIG_INTEL_IOMMU_SVM
+ if (ecap_vcs(iommu->ecap) && vccap_pasid(iommu->vccap)) {
+ pr_info("Register custom PASID allocator\n");
+ /*
+ * 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");
+ /*
+ * Disable scalable mode on this IOMMU if there
+ * is no custom allocator. Mixing SM capable vIOMMU
+ * and non-SM vIOMMU are not supported.
+ */
+ intel_iommu_sm = 0;
+ }
+ }
+#endif
}
bus_set_iommu(&pci_bus_type, &intel_iommu_ops);
diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index 1d4b8dcdc5d8..c624733cb2e6 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -19,6 +19,7 @@
#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>
@@ -546,6 +547,7 @@ 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_ops 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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