diff --git a/src/perfctr.c b/src/perfctr.c
index 2b312affd4..0ec59b6ba8 100644
--- a/src/perfctr.c
+++ b/src/perfctr.c
@@ -56,6 +56,9 @@ HSAKMT_STATUS init_counter_props(unsigned int NumNodes)
 		return HSAKMT_STATUS_NO_MEMORY;
 
 	counter_props_count = NumNodes;
+
+	alloc_pmc_blocks();
+
 	return HSAKMT_STATUS_SUCCESS;
 }
 
@@ -73,18 +76,24 @@ void destroy_counter_props(void)
 		}
 
 	free(counter_props);
+	free_pmc_blocks();
 }
 
 static int blockid2uuid(enum perf_block_id block_id, HSA_UUID *uuid)
 {
 	int rc = 0;
+
 	switch (block_id) {
 	case PERFCOUNTER_BLOCKID__SQ:
 		*uuid = HSA_PROFILEBLOCK_AMD_SQ;
 		break;
+	case PERFCOUNTER_BLOCKID__IOMMUV2:
+		*uuid = HSA_PROFILEBLOCK_AMD_IOMMUV2;
+		break;
 	default:
 		/* If we reach this point, it's a bug */
 		rc = -1;
+		break;
 	}
 
 	return rc;
@@ -99,11 +108,12 @@ hsaKmtPmcGetCounterProperties(
 {
 	HSAKMT_STATUS rc = HSAKMT_STATUS_SUCCESS;
 	uint32_t gpu_id, i, block_id;
-	uint16_t dev_id;
 	uint32_t counter_props_size = 0;
 	uint32_t total_counters = 0;
 	uint32_t total_concurrent = 0;
 	struct perf_counter_block block = {0};
+	uint32_t total_blocks = 0;
+	uint32_t entry;
 
 	if (counter_props == NULL)
 		return HSAKMT_STATUS_NO_MEMORY;
@@ -114,50 +124,63 @@ hsaKmtPmcGetCounterProperties(
 	if (validate_nodeid(NodeId, &gpu_id) != 0)
 		return HSAKMT_STATUS_INVALID_NODE_UNIT;
 
-	if (counter_props[NodeId] == NULL) {
-		dev_id = get_device_id_by_node(NodeId);
-		for (i = 0; i < PERFCOUNTER_BLOCKID__MAX; i++) {
-			rc = get_block_properties(dev_id, i, &block);
-			if (rc != HSAKMT_STATUS_SUCCESS)
-				return rc;
-			total_concurrent += block.num_of_slots;
-			total_counters += block.num_of_counters;
+	if (counter_props[NodeId] != NULL) {
+		*CounterProperties = counter_props[NodeId];
+		return HSAKMT_STATUS_SUCCESS;
+	}
+
+	for (i = 0; i < PERFCOUNTER_BLOCKID__MAX; i++) {
+		rc = get_block_properties(NodeId, i, &block);
+		if (rc != HSAKMT_STATUS_SUCCESS)
+			return rc;
+		total_concurrent += block.num_of_slots;
+		total_counters += block.num_of_counters;
+		/* If num_of_slots=0, this block doesn't exist */
+		if (block.num_of_slots)
+			total_blocks++;
+	}
+
+	counter_props_size = sizeof(HsaCounterProperties) +
+			sizeof(HsaCounterBlockProperties)*(total_blocks-1) +
+			sizeof(HsaCounter)*(total_counters-1);
+
+	counter_props[NodeId] = malloc(counter_props_size);
+	if (counter_props[NodeId] == NULL)
+		return HSAKMT_STATUS_NO_MEMORY;
+
+	counter_props[NodeId]->NumBlocks = total_blocks;
+	counter_props[NodeId]->NumConcurrent = total_concurrent;
+
+	entry = 0;
+	for (block_id = 0; block_id < PERFCOUNTER_BLOCKID__MAX; block_id++) {
+		rc = get_block_properties(NodeId, block_id, &block);
+		if (rc != HSAKMT_STATUS_SUCCESS) {
+			free(counter_props[NodeId]);
+			return rc;
 		}
 
-		counter_props_size = sizeof(HsaCounterProperties) +
-		sizeof(HsaCounterBlockProperties)*(PERFCOUNTER_BLOCKID__MAX-1) +
-		sizeof(HsaCounter)*(total_counters-1);
+		if (!block.num_of_slots) /* not a valid block */
+			continue;
 
-		counter_props[NodeId] = malloc(counter_props_size);
+		blockid2uuid(block_id,
+			&counter_props[NodeId]->Blocks[entry].BlockId);
+		counter_props[NodeId]->Blocks[entry].NumCounters =
+					block.num_of_counters;
+		counter_props[NodeId]->Blocks[entry].NumConcurrent =
+					block.num_of_slots;
 
-		if (counter_props[NodeId] == NULL)
-			return HSAKMT_STATUS_NO_MEMORY;
-
-		counter_props[NodeId]->NumBlocks = PERFCOUNTER_BLOCKID__MAX;
-		counter_props[NodeId]->NumConcurrent = total_concurrent;
-
-		for (block_id = 0; block_id < PERFCOUNTER_BLOCKID__MAX; block_id++)
-		{
-			rc = get_block_properties(dev_id, block_id, &block);
-			if (rc != HSAKMT_STATUS_SUCCESS) {
-				free(counter_props[NodeId]);
-				return rc;
-			}
-
-			/* Filling the SQ block */
-			blockid2uuid(block_id, &counter_props[NodeId]->Blocks[block_id].BlockId);
-			counter_props[NodeId]->Blocks[block_id].NumCounters = block.num_of_counters;
-			counter_props[NodeId]->Blocks[block_id].NumConcurrent = block.num_of_slots;
-
-			for (i = 0; i < block.num_of_counters; i++) {
-				counter_props[NodeId]->Blocks[block_id].Counters[i].BlockIndex = block_id;
-				counter_props[NodeId]->Blocks[block_id].Counters[i].CounterId = block.counter_ids[i];
-				counter_props[NodeId]->Blocks[block_id].Counters[i].CounterSizeInBits = block.counter_size_in_bits;
-				counter_props[NodeId]->Blocks[block_id].Counters[i].CounterMask = block.counter_mask;
-				counter_props[NodeId]->Blocks[block_id].Counters[i].Flags.ui32.Global = 1;
-				counter_props[NodeId]->Blocks[block_id].Counters[i].Type = HSA_PROFILE_TYPE_NONPRIV_IMMEDIATE;
-			}
+		for (i = 0; i < block.num_of_counters; i++) {
+			counter_props[NodeId]->Blocks[entry].Counters[i].BlockIndex = block_id;
+			counter_props[NodeId]->Blocks[entry].Counters[i].CounterId = block.counter_ids[i];
+			counter_props[NodeId]->Blocks[entry].Counters[i].CounterSizeInBits = block.counter_size_in_bits;
+			counter_props[NodeId]->Blocks[entry].Counters[i].CounterMask = block.counter_mask;
+			counter_props[NodeId]->Blocks[entry].Counters[i].Flags.ui32.Global = 1;
+			if (block_id == PERFCOUNTER_BLOCKID__IOMMUV2)
+				counter_props[NodeId]->Blocks[entry].Counters[i].Type = HSA_PROFILE_TYPE_PRIVILEGED_IMMEDIATE;
+			else
+				counter_props[NodeId]->Blocks[entry].Counters[i].Type = HSA_PROFILE_TYPE_NONPRIV_IMMEDIATE;
 		}
+		entry++;
 	}
 
 	*CounterProperties = counter_props[NodeId];
diff --git a/src/pmc_table.c b/src/pmc_table.c
index b0db2fea70..6465507c41 100644
--- a/src/pmc_table.c
+++ b/src/pmc_table.c
@@ -23,6 +23,11 @@
  * DEALINGS IN THE SOFTWARE.
  */
 
+#include <sys/types.h>
+#include <dirent.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
 #include "libhsakmt.h"
 #include "pmc_table.h"
 
@@ -182,15 +187,135 @@ static struct perf_counter_block polaris_blocks[PERFCOUNTER_BLOCKID__MAX] = {
 	},
 };
 
+/* Current APUs only have one IOMMU. If NUMA is introduced to APUs, we'll need
+ * to expand the struct here to an array.
+ */
+static struct perf_counter_block iommu_block;
+
+static HSAKMT_STATUS
+alloc_pmc_blocks_iommu(void)
+{
+	DIR *dir;
+	struct dirent *dent;
+	const char sysfs_amdiommu_event_path[] =
+			"/sys/bus/event_source/devices/amd_iommu/events";
+	/* Counter source in IOMMU's Counter Bank Addressing register is 8 bits,
+	 * so the biggest counter number/id possible is 0xff.
+	 */
+	const int max_counter_id = 0xff;
+	char path[256];
+	const int len = sizeof(path);
+	FILE *file;
+	int num;
+	char counter_id[max_counter_id + 1];
+	HSAKMT_STATUS ret = HSAKMT_STATUS_SUCCESS;
+	uint32_t *ptr;
+	struct perf_counter_block *block = &iommu_block;
+
+	memset(block, 0, sizeof(struct perf_counter_block));
+
+	dir = opendir(sysfs_amdiommu_event_path);
+	if (!dir)
+		goto out;
+
+	memset(counter_id, 0, max_counter_id + 1);
+	while ((dent = readdir(dir))) {
+		if (!strcmp(dent->d_name, ".") || !strcmp(dent->d_name, ".."))
+			continue;
+		if (snprintf(path, len, "%s/%s", sysfs_amdiommu_event_path,
+						dent->d_name) >= len) {
+			fprintf(stderr, "Increase path length.\n");
+			ret = HSAKMT_STATUS_NO_MEMORY;
+			goto out;
+		}
+		file = fopen(path, "r");
+		if (!file) {
+			ret = HSAKMT_STATUS_ERROR;
+			goto out;
+		}
+		if (fscanf(file, "csource=0x%x", &num) != 1) {
+			ret = HSAKMT_STATUS_ERROR;
+			fclose(file);
+			goto out;
+		}
+		if (num > max_counter_id)
+		/* This should never happen. If it does, check IOMMU driver. */
+			fprintf(stderr,
+				"Error: max_counter_id %d is set too small.\n",
+				max_counter_id);
+		else {
+			counter_id[num] = 1;
+			++block->num_of_counters;
+		}
+		fclose(file);
+	}
+
+	block->counter_ids = malloc(sizeof(uint32_t) * block->num_of_counters);
+	if (!block->counter_ids) {
+		ret = HSAKMT_STATUS_NO_MEMORY;
+		goto out;
+	}
+	ptr = block->counter_ids;
+	for (num = 0; num < (max_counter_id + 1); num++) {
+		if (counter_id[num]) {
+			ptr[0] = num;
+			++ptr;
+		}
+	}
+
+	if (snprintf(path, len, "%s/%d/%s",
+		"/sys/devices/virtual/kfd/kfd/topology/nodes",
+		0, /* IOMMU is in node 0. Change this if NUMA is introduced to APU. */
+		"perf/iommu/max_concurrent") >= len) {
+		fprintf(stderr, "Increase path length\n");
+		ret = HSAKMT_STATUS_NO_MEMORY;
+		goto out;
+	};
+	file = fopen(path, "r");
+	if (!file) {
+		ret = HSAKMT_STATUS_ERROR;
+		goto out;
+	}
+	if (fscanf(file, "%d", &block->num_of_slots) != 1)
+		ret = HSAKMT_STATUS_ERROR;
+	fclose(file);
+
+out:
+	if (dir)
+		closedir(dir);
+	return ret;
+}
+
+HSAKMT_STATUS alloc_pmc_blocks(void)
+{
+	return alloc_pmc_blocks_iommu();
+}
+
+void free_pmc_blocks(void)
+{
+	if (iommu_block.counter_ids)
+		free(iommu_block.counter_ids);
+	iommu_block.counter_ids = NULL;
+	iommu_block.num_of_counters = 0;
+}
+
 HSAKMT_STATUS
-get_block_properties(uint16_t dev_id,
-		 enum perf_block_id block_id,
-		 struct perf_counter_block *block)
+get_block_properties(uint32_t node_id,
+                     enum perf_block_id block_id,
+                     struct perf_counter_block *block)
 {
 	HSAKMT_STATUS rc = HSAKMT_STATUS_SUCCESS;
-	if (block_id > PERFCOUNTER_BLOCKID__MAX || block_id < PERFCOUNTER_BLOCKID__FIRST)
+	uint16_t dev_id = get_device_id_by_node(node_id);
+
+	if (block_id > PERFCOUNTER_BLOCKID__MAX ||
+			block_id < PERFCOUNTER_BLOCKID__FIRST)
 		return HSAKMT_STATUS_INVALID_PARAMETER;
 
+	if (block_id == PERFCOUNTER_BLOCKID__IOMMUV2) {
+		*block = iommu_block;
+		return HSAKMT_STATUS_SUCCESS;
+	}
+
 	/* To avoid the long list, we read the 12 most significant digits of DID
 	 * to identify the GPU instead of listing the complete 16 bits. If one
 	 * day 12-bits is not good enough to distinguish the GPU, change the
diff --git a/src/pmc_table.h b/src/pmc_table.h
index 820edae4e0..adc4af2298 100644
--- a/src/pmc_table.h
+++ b/src/pmc_table.h
@@ -31,6 +31,7 @@
 enum perf_block_id {
 	PERFCOUNTER_BLOCKID__FIRST = 0,
 	PERFCOUNTER_BLOCKID__SQ = PERFCOUNTER_BLOCKID__FIRST,
+	PERFCOUNTER_BLOCKID__IOMMUV2,
 	PERFCOUNTER_BLOCKID__MAX
 };
 
@@ -42,9 +43,12 @@ struct perf_counter_block {
 	uint64_t    counter_mask;
 };
 
+HSAKMT_STATUS alloc_pmc_blocks(void);
+void free_pmc_blocks(void);
+
 HSAKMT_STATUS
-get_block_properties(uint16_t dev_id,
-		 enum perf_block_id block_id,
-		 struct perf_counter_block *block);
+get_block_properties(uint32_t node_id,
+                     enum perf_block_id block_id,
+                     struct perf_counter_block *block);
 
 #endif // PMC_TABLE_H