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From:   Eric Auger <eric.auger@redhat.com>
To:     eric.auger.pro@gmail.com, eric.auger@redhat.com,
        iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
        kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu, will@kernel.org,
        joro@8bytes.org, maz@kernel.org, robin.murphy@arm.com
Cc:     jean-philippe@linaro.org, zhangfei.gao@linaro.org,
        zhangfei.gao@gmail.com, vivek.gautam@arm.com,
        shameerali.kolothum.thodi@huawei.com, alex.williamson@redhat.com,
        jacob.jun.pan@linux.intel.com, yi.l.liu@intel.com, tn@semihalf.com,
        nicoleotsuka@gmail.com
Subject: [PATCH v12 13/15] iommu/smmuv3: Report non recoverable faults
Date:   Mon, 16 Nov 2020 11:43:14 +0100
Message-Id: <20201116104316.31816-14-eric.auger@redhat.com>
In-Reply-To: <20201116104316.31816-1-eric.auger@redhat.com>
References: <20201116104316.31816-1-eric.auger@redhat.com>
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When a stage 1 related fault event is read from the event queue,
let's propagate it to potential external fault listeners, ie. users
who registered a fault handler.

Signed-off-by: Eric Auger <eric.auger@redhat.com>

---
v8 -> v9:
- adapt to the removal of IOMMU_FAULT_UNRECOV_PERM_VALID:
  only look at IOMMU_FAULT_UNRECOV_ADDR_VALID which comes with
  perm
- do not advertise IOMMU_FAULT_UNRECOV_PASID_VALID faults for
  translation faults
- trace errors if !master
- test nested before calling iommu_report_device_fault
- call the fault handler unconditionnally in non nested mode

v4 -> v5:
- s/IOMMU_FAULT_PERM_INST/IOMMU_FAULT_PERM_EXEC
---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 102 +++++++++++++++++---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h |  80 +++++++++++++++
 2 files changed, 171 insertions(+), 11 deletions(-)

diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index 5aa9e0e747fa..31a2500bde32 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -1379,7 +1379,6 @@ static int arm_smmu_init_l2_strtab(struct arm_smmu_device *smmu, u32 sid)
 	return 0;
 }
 
-__maybe_unused
 static struct arm_smmu_master *
 arm_smmu_find_master(struct arm_smmu_device *smmu, u32 sid)
 {
@@ -1405,25 +1404,106 @@ arm_smmu_find_master(struct arm_smmu_device *smmu, u32 sid)
 	return master;
 }
 
+/* Populates the record fields according to the input SMMU event */
+static bool arm_smmu_transcode_fault(u64 *evt, u8 type,
+				     struct iommu_fault_unrecoverable *record)
+{
+	const struct arm_smmu_fault_propagation_data *data;
+	u32 fields;
+
+	if (type >= ARRAY_SIZE(fault_propagation))
+		return false;
+
+	data = &fault_propagation[type];
+	if (!data->reason)
+		return false;
+
+	fields = data->fields;
+
+	if (data->s1_check & FIELD_GET(EVTQ_1_S2, evt[1]))
+		return false; /* S2 related fault, don't propagate */
+
+	if (fields & IOMMU_FAULT_UNRECOV_PASID_VALID)
+		record->pasid = FIELD_GET(EVTQ_0_SUBSTREAMID, evt[0]);
+	else {
+		/* all other transcoded errors have SSV */
+		if (FIELD_GET(EVTQ_0_SSV, evt[0])) {
+			record->pasid = FIELD_GET(EVTQ_0_SUBSTREAMID, evt[0]);
+			fields |= IOMMU_FAULT_UNRECOV_PASID_VALID;
+		}
+	}
+
+	if (fields & IOMMU_FAULT_UNRECOV_ADDR_VALID) {
+		if (FIELD_GET(EVTQ_1_RNW, evt[1]))
+			record->perm = IOMMU_FAULT_PERM_READ;
+		else
+			record->perm = IOMMU_FAULT_PERM_WRITE;
+		if (FIELD_GET(EVTQ_1_PNU, evt[1]))
+			record->perm |= IOMMU_FAULT_PERM_PRIV;
+		if (FIELD_GET(EVTQ_1_IND, evt[1]))
+			record->perm |= IOMMU_FAULT_PERM_EXEC;
+		record->addr = evt[2];
+	}
+
+	if (fields & IOMMU_FAULT_UNRECOV_FETCH_ADDR_VALID)
+		record->fetch_addr = FIELD_GET(EVTQ_3_FETCH_ADDR, evt[3]);
+
+	record->flags = fields;
+	record->reason = data->reason;
+	return true;
+}
+
+static void arm_smmu_report_event(struct arm_smmu_device *smmu, u64 *evt)
+{
+	u32 sid = FIELD_GET(EVTQ_0_STREAMID, evt[0]);
+	u8 type = FIELD_GET(EVTQ_0_ID, evt[0]);
+	struct arm_smmu_master *master;
+	struct iommu_fault_event event = {};
+	bool nested;
+	int i;
+
+	master = arm_smmu_find_master(smmu, sid);
+	if (!master || !master->domain)
+		goto out;
+
+	event.fault.type = IOMMU_FAULT_DMA_UNRECOV;
+
+	nested = (master->domain->stage == ARM_SMMU_DOMAIN_NESTED);
+
+	if (nested) {
+		if (arm_smmu_transcode_fault(evt, type, &event.fault.event)) {
+			/*
+			 * Only S1 related faults should be reported to the
+			 * guest and must not flood the host log.
+			 * Also a fault handler should have been registered
+			 * to guarantee the full nested functionality
+			 */
+			WARN_ON_ONCE(iommu_report_device_fault(master->dev,
+							       &event));
+			return;
+		}
+	} else {
+		iommu_report_device_fault(master->dev, &event);
+	}
+out:
+	dev_info(smmu->dev, "event 0x%02x received:\n", type);
+	for (i = 0; i < EVTQ_ENT_DWORDS; ++i) {
+		dev_info(smmu->dev, "\t0x%016llx\n",
+			 (unsigned long long)evt[i]);
+	}
+}
+
 /* IRQ and event handlers */
 static irqreturn_t arm_smmu_evtq_thread(int irq, void *dev)
 {
-	int i;
 	struct arm_smmu_device *smmu = dev;
 	struct arm_smmu_queue *q = &smmu->evtq.q;
 	struct arm_smmu_ll_queue *llq = &q->llq;
 	u64 evt[EVTQ_ENT_DWORDS];
 
 	do {
-		while (!queue_remove_raw(q, evt)) {
-			u8 id = FIELD_GET(EVTQ_0_ID, evt[0]);
-
-			dev_info(smmu->dev, "event 0x%02x received:\n", id);
-			for (i = 0; i < ARRAY_SIZE(evt); ++i)
-				dev_info(smmu->dev, "\t0x%016llx\n",
-					 (unsigned long long)evt[i]);
-
-		}
+		while (!queue_remove_raw(q, evt))
+			arm_smmu_report_event(smmu, evt);
 
 		/*
 		 * Not much we can do on overflow, so scream and pretend we're
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
index f30d0384f906..0802a3813678 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
@@ -152,6 +152,26 @@
 #define ARM_SMMU_PRIQ_IRQ_CFG1		0xd8
 #define ARM_SMMU_PRIQ_IRQ_CFG2		0xdc
 
+/* Events */
+#define ARM_SMMU_EVT_F_UUT		0x01
+#define ARM_SMMU_EVT_C_BAD_STREAMID	0x02
+#define ARM_SMMU_EVT_F_STE_FETCH	0x03
+#define ARM_SMMU_EVT_C_BAD_STE		0x04
+#define ARM_SMMU_EVT_F_BAD_ATS_TREQ	0x05
+#define ARM_SMMU_EVT_F_STREAM_DISABLED	0x06
+#define ARM_SMMU_EVT_F_TRANSL_FORBIDDEN	0x07
+#define ARM_SMMU_EVT_C_BAD_SUBSTREAMID	0x08
+#define ARM_SMMU_EVT_F_CD_FETCH		0x09
+#define ARM_SMMU_EVT_C_BAD_CD		0x0a
+#define ARM_SMMU_EVT_F_WALK_EABT	0x0b
+#define ARM_SMMU_EVT_F_TRANSLATION	0x10
+#define ARM_SMMU_EVT_F_ADDR_SIZE	0x11
+#define ARM_SMMU_EVT_F_ACCESS		0x12
+#define ARM_SMMU_EVT_F_PERMISSION	0x13
+#define ARM_SMMU_EVT_F_TLB_CONFLICT	0x20
+#define ARM_SMMU_EVT_F_CFG_CONFLICT	0x21
+#define ARM_SMMU_EVT_E_PAGE_REQUEST	0x24
+
 #define ARM_SMMU_REG_SZ			0xe00
 
 /* Common MSI config fields */
@@ -370,6 +390,15 @@
 #define EVTQ_MAX_SZ_SHIFT		(Q_MAX_SZ_SHIFT - EVTQ_ENT_SZ_SHIFT)
 
 #define EVTQ_0_ID			GENMASK_ULL(7, 0)
+#define EVTQ_0_SSV			GENMASK_ULL(11, 11)
+#define EVTQ_0_SUBSTREAMID		GENMASK_ULL(31, 12)
+#define EVTQ_0_STREAMID			GENMASK_ULL(63, 32)
+#define EVTQ_1_PNU			GENMASK_ULL(33, 33)
+#define EVTQ_1_IND			GENMASK_ULL(34, 34)
+#define EVTQ_1_RNW			GENMASK_ULL(35, 35)
+#define EVTQ_1_S2			GENMASK_ULL(39, 39)
+#define EVTQ_1_CLASS			GENMASK_ULL(40, 41)
+#define EVTQ_3_FETCH_ADDR		GENMASK_ULL(51, 3)
 
 /* PRI queue */
 #define PRIQ_ENT_SZ_SHIFT		4
@@ -690,6 +719,57 @@ struct arm_smmu_domain {
 	spinlock_t			devices_lock;
 };
 
+/* fault propagation */
+struct arm_smmu_fault_propagation_data {
+	enum iommu_fault_reason reason;
+	bool s1_check;
+	u32 fields; /* IOMMU_FAULT_UNRECOV_*_VALID bits */
+};
+
+/*
+ * Describes how SMMU faults translate into generic IOMMU faults
+ * and if they need to be reported externally
+ */
+static const struct arm_smmu_fault_propagation_data fault_propagation[] = {
+[ARM_SMMU_EVT_F_UUT]			= { },
+[ARM_SMMU_EVT_C_BAD_STREAMID]		= { },
+[ARM_SMMU_EVT_F_STE_FETCH]		= { },
+[ARM_SMMU_EVT_C_BAD_STE]		= { },
+[ARM_SMMU_EVT_F_BAD_ATS_TREQ]		= { },
+[ARM_SMMU_EVT_F_STREAM_DISABLED]	= { },
+[ARM_SMMU_EVT_F_TRANSL_FORBIDDEN]	= { },
+[ARM_SMMU_EVT_C_BAD_SUBSTREAMID]	= {IOMMU_FAULT_REASON_PASID_INVALID,
+					   false,
+					   IOMMU_FAULT_UNRECOV_PASID_VALID
+					  },
+[ARM_SMMU_EVT_F_CD_FETCH]		= {IOMMU_FAULT_REASON_PASID_FETCH,
+					   false,
+					   IOMMU_FAULT_UNRECOV_FETCH_ADDR_VALID
+					  },
+[ARM_SMMU_EVT_C_BAD_CD]			= {IOMMU_FAULT_REASON_BAD_PASID_ENTRY,
+					   false,
+					  },
+[ARM_SMMU_EVT_F_WALK_EABT]		= {IOMMU_FAULT_REASON_WALK_EABT, true,
+					   IOMMU_FAULT_UNRECOV_ADDR_VALID |
+					   IOMMU_FAULT_UNRECOV_FETCH_ADDR_VALID
+					  },
+[ARM_SMMU_EVT_F_TRANSLATION]		= {IOMMU_FAULT_REASON_PTE_FETCH, true,
+					   IOMMU_FAULT_UNRECOV_ADDR_VALID
+					  },
+[ARM_SMMU_EVT_F_ADDR_SIZE]		= {IOMMU_FAULT_REASON_OOR_ADDRESS, true,
+					   IOMMU_FAULT_UNRECOV_ADDR_VALID
+					  },
+[ARM_SMMU_EVT_F_ACCESS]			= {IOMMU_FAULT_REASON_ACCESS, true,
+					   IOMMU_FAULT_UNRECOV_ADDR_VALID
+					  },
+[ARM_SMMU_EVT_F_PERMISSION]		= {IOMMU_FAULT_REASON_PERMISSION, true,
+					   IOMMU_FAULT_UNRECOV_ADDR_VALID
+					  },
+[ARM_SMMU_EVT_F_TLB_CONFLICT]		= { },
+[ARM_SMMU_EVT_F_CFG_CONFLICT]		= { },
+[ARM_SMMU_EVT_E_PAGE_REQUEST]		= { },
+};
+
 extern struct xarray arm_smmu_asid_xa;
 extern struct mutex arm_smmu_asid_lock;
 
-- 
2.21.3