[PATCH 12/12] drm/amdkfd: Add sanity checks in IRQ handlers

[Felix Kuehling]

Only accept interrupts from KFD VMIDs. Just checking for a PASID may
not be enough because amdgpu started using PASIDs to map VM faults
to processes.

Warn if an IRQ doesn't have a valid PASID (indicating a firmware bug).

Suggested-by: Shaoyun Liu <Shaoyun.Liu at amd.com>
Suggested-by: Oak Zeng <Oak.Zeng at amd.com>
Signed-off-by: Felix Kuehling <Felix.Kuehling at amd.com>
---
 drivers/gpu/drm/amd/amdkfd/cik_event_interrupt.c | 20 +++++++++---
 drivers/gpu/drm/amd/amdkfd/kfd_int_process_v9.c  | 40 ++++++++++++++----------
 2 files changed, 39 insertions(+), 21 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/cik_event_interrupt.c b/drivers/gpu/drm/amd/amdkfd/cik_event_interrupt.c
index 3d5ccb3..49df6c7 100644
--- a/drivers/gpu/drm/amd/amdkfd/cik_event_interrupt.c
+++ b/drivers/gpu/drm/amd/amdkfd/cik_event_interrupt.c
@@ -27,18 +27,28 @@
 static bool cik_event_interrupt_isr(struct kfd_dev *dev,
 					const uint32_t *ih_ring_entry)
 {
-	unsigned int pasid;
 	const struct cik_ih_ring_entry *ihre =
 			(const struct cik_ih_ring_entry *)ih_ring_entry;
+	unsigned int vmid, pasid;
+
+	/* Only handle interrupts from KFD VMIDs */
+	vmid  = (ihre->ring_id & 0x0000ff00) >> 8;
+	if (vmid < dev->vm_info.first_vmid_kfd ||
+	    vmid > dev->vm_info.last_vmid_kfd)
+		return 0;
 
+	/* If there is no valid PASID, it's likely a firmware bug */
 	pasid = (ihre->ring_id & 0xffff0000) >> 16;
+	if (WARN_ONCE(pasid == 0, "FW bug: No PASID in KFD interrupt"))
+		return 0;
 
-	/* Do not process in ISR, just request it to be forwarded to WQ. */
-	return (pasid != 0) &&
-		(ihre->source_id == CIK_INTSRC_CP_END_OF_PIPE ||
+	/* Interrupt types we care about: various signals and faults.
+	 * They will be forwarded to a work queue (see below).
+	 */
+	return ihre->source_id == CIK_INTSRC_CP_END_OF_PIPE ||
 		ihre->source_id == CIK_INTSRC_SDMA_TRAP ||
 		ihre->source_id == CIK_INTSRC_SQ_INTERRUPT_MSG ||
-		ihre->source_id == CIK_INTSRC_CP_BAD_OPCODE);
+		ihre->source_id == CIK_INTSRC_CP_BAD_OPCODE;
 }
 
 static void cik_event_interrupt_wq(struct kfd_dev *dev,
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_int_process_v9.c b/drivers/gpu/drm/amd/amdkfd/kfd_int_process_v9.c
index 39d4115..37029ba 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_int_process_v9.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_int_process_v9.c
@@ -29,27 +29,35 @@ static bool event_interrupt_isr_v9(struct kfd_dev *dev,
 					const uint32_t *ih_ring_entry)
 {
 	uint16_t source_id, client_id, pasid, vmid;
+	const uint32_t *data = ih_ring_entry;
 
-	source_id = SOC15_SOURCE_ID_FROM_IH_ENTRY(ih_ring_entry);
-	client_id = SOC15_CLIENT_ID_FROM_IH_ENTRY(ih_ring_entry);
-	pasid = SOC15_PASID_FROM_IH_ENTRY(ih_ring_entry);
+	/* Only handle interrupts from KFD VMIDs */
 	vmid = SOC15_VMID_FROM_IH_ENTRY(ih_ring_entry);
+	if (vmid < dev->vm_info.first_vmid_kfd ||
+	    vmid > dev->vm_info.last_vmid_kfd)
+		return 0;
+
+	/* If there is no valid PASID, it's likely a firmware bug */
+	pasid = SOC15_PASID_FROM_IH_ENTRY(ih_ring_entry);
+	if (WARN_ONCE(pasid == 0, "FW bug: No PASID in KFD interrupt"))
+		return 0;
 
-	if (pasid) {
-		const uint32_t *data = ih_ring_entry;
+	source_id = SOC15_SOURCE_ID_FROM_IH_ENTRY(ih_ring_entry);
+	client_id = SOC15_CLIENT_ID_FROM_IH_ENTRY(ih_ring_entry);
 
-		pr_debug("client id 0x%x, source id %d, pasid 0x%x. raw data:\n",
-			 client_id, source_id, pasid);
-		pr_debug("%8X, %8X, %8X, %8X, %8X, %8X, %8X, %8X.\n",
-			 data[0], data[1], data[2], data[3],
-			 data[4], data[5], data[6], data[7]);
-	}
+	pr_debug("client id 0x%x, source id %d, pasid 0x%x. raw data:\n",
+		 client_id, source_id, pasid);
+	pr_debug("%8X, %8X, %8X, %8X, %8X, %8X, %8X, %8X.\n",
+		 data[0], data[1], data[2], data[3],
+		 data[4], data[5], data[6], data[7]);
 
-	return (pasid != 0) &&
-		(source_id == SOC15_INTSRC_CP_END_OF_PIPE ||
-		 source_id == SOC15_INTSRC_SDMA_TRAP ||
-		 source_id == SOC15_INTSRC_SQ_INTERRUPT_MSG ||
-		 source_id == SOC15_INTSRC_CP_BAD_OPCODE);
+	/* Interrupt types we care about: various signals and faults.
+	 * They will be forwarded to a work queue (see below).
+	 */
+	return source_id == SOC15_INTSRC_CP_END_OF_PIPE ||
+		source_id == SOC15_INTSRC_SDMA_TRAP ||
+		source_id == SOC15_INTSRC_SQ_INTERRUPT_MSG ||
+		source_id == SOC15_INTSRC_CP_BAD_OPCODE;
 }
 
 static void event_interrupt_wq_v9(struct kfd_dev *dev,
-- 
2.7.4