diff --git a/lib/i915/gem_engine_topology.c b/lib/i915/gem_engine_topology.c
index 790d455ff..f5033318b 100644
--- a/lib/i915/gem_engine_topology.c
+++ b/lib/i915/gem_engine_topology.c
@@ -21,7 +21,12 @@
  * IN THE SOFTWARE.
  */
 
+#include <fcntl.h>
+#include <unistd.h>
+
 #include "drmtest.h"
+#include "igt_sysfs.h"
+#include "intel_chipset.h"
 #include "ioctl_wrappers.h"
 
 #include "i915/gem_engine_topology.h"
@@ -337,3 +342,82 @@ bool gem_engine_is_equal(const struct intel_execution_engine2 *e1,
 {
 	return e1->class == e2->class && e1->instance == e2->instance;
 }
+
+static int subdir(int dir, const char *path)
+{
+	int fd;
+
+	fd = openat(dir, path, O_RDONLY);
+	close(dir);
+
+	return fd;
+}
+
+int gem_engine_property_scanf(int i915, const char *engine, const char *attr,
+			      const char *fmt, ...)
+{
+	int dir, fd;
+	FILE *file;
+	va_list ap;
+	int ret;
+
+	dir = igt_sysfs_open(i915);
+	if (dir < 0)
+		return dir;
+
+	dir = subdir(dir, "engine");
+	if (dir < 0)
+		return dir;
+
+	dir = subdir(dir, engine);
+	if (dir < 0)
+		return dir;
+
+	fd = openat(dir, attr, O_RDONLY);
+	if (fd < 0)
+		return fd;
+
+	file = fdopen(fd, "r");
+	if (!file) {
+		close(fd);
+		return -1;
+	}
+
+	va_start(ap, fmt);
+	ret = vfscanf(file, fmt, ap);
+	va_end(ap);
+
+	fclose(file);
+	return ret;
+}
+
+uint32_t gem_engine_mmio_base(int i915, const char *engine)
+{
+	unsigned int mmio = 0;
+
+	if (gem_engine_property_scanf(i915, engine, "mmio_base",
+				      "%x", &mmio) < 0) {
+		int gen = intel_gen(intel_get_drm_devid(i915));
+
+		/* The layout of xcs1+ is unreliable -- hence the property! */
+		if (!strcmp(engine, "rcs0")) {
+			mmio = 0x2000;
+		} else if (!strcmp(engine, "bcs0")) {
+			mmio = 0x22000;
+		} else if (!strcmp(engine, "vcs0")) {
+			if (gen < 6)
+				mmio = 0x4000;
+			else if (gen < 11)
+				mmio = 0x12000;
+			else
+				mmio = 0x1c0000;
+		} else if (!strcmp(engine, "vecs0")) {
+			if (gen < 11)
+				mmio = 0x1a000;
+			else
+				mmio = 0x1c8000;
+		}
+	}
+
+	return mmio;
+}
diff --git a/lib/i915/gem_engine_topology.h b/lib/i915/gem_engine_topology.h
index d98773e06..e728ebd93 100644
--- a/lib/i915/gem_engine_topology.h
+++ b/lib/i915/gem_engine_topology.h
@@ -74,4 +74,9 @@ struct intel_execution_engine2 gem_eb_flags_to_engine(unsigned int flags);
 	     ((e__) = intel_get_current_physical_engine(&i__)); \
 	     intel_next_engine(&i__))
 
+__attribute__((format(scanf, 4, 5)))
+int gem_engine_property_scanf(int i915, const char *engine, const char *attr,
+			      const char *fmt, ...);
+uint32_t gem_engine_mmio_base(int i915, const char *engine);
+
 #endif /* GEM_ENGINE_TOPOLOGY_H */
diff --git a/tests/i915/gem_ctx_shared.c b/tests/i915/gem_ctx_shared.c
index f78524822..52b91963a 100644
--- a/tests/i915/gem_ctx_shared.c
+++ b/tests/i915/gem_ctx_shared.c
@@ -38,6 +38,7 @@
 
 #include <drm.h>
 
+#include "i915/gem_engine_topology.h"
 #include "igt_rand.h"
 #include "igt_vgem.h"
 #include "sync_file.h"
@@ -558,6 +559,16 @@ static uint32_t store_timestamp(int i915,
 	return obj.handle;
 }
 
+static uint32_t ring_base(int i915, unsigned ring)
+{
+	struct intel_execution_engine2 e;
+
+	if (ring == I915_EXEC_DEFAULT)
+		ring = I915_EXEC_RENDER; /* XXX */
+
+	return gem_engine_mmio_base(i915, gem_eb_flags_to_engine(ring).name);
+}
+
 static void independent(int i915, unsigned ring, unsigned flags)
 {
 	const int TIMESTAMP = 1023;
@@ -565,33 +576,8 @@ static void independent(int i915, unsigned ring, unsigned flags)
 	igt_spin_t *spin[MAX_ELSP_QLEN];
 	unsigned int mmio_base;
 
-	/* XXX i915_query()! */
-	switch (ring) {
-	case I915_EXEC_DEFAULT:
-	case I915_EXEC_RENDER:
-		mmio_base = 0x2000;
-		break;
-#if 0
-	case I915_EXEC_BSD:
-		mmio_base = 0x12000;
-		break;
-#endif
-	case I915_EXEC_BLT:
-		mmio_base = 0x22000;
-		break;
-
-#define GEN11_VECS0_BASE 0x1c8000
-#define GEN11_VECS1_BASE 0x1d8000
-	case I915_EXEC_VEBOX:
-		if (intel_gen(intel_get_drm_devid(i915)) >= 11)
-			mmio_base = GEN11_VECS0_BASE;
-		else
-			mmio_base = 0x1a000;
-		break;
-
-	default:
-		igt_skip("mmio base not known\n");
-	}
+	mmio_base = ring_base(i915, ring);
+	igt_require_f(mmio_base, "mmio base not known\n");
 
 	for (int n = 0; n < ARRAY_SIZE(spin); n++) {
 		const struct igt_spin_factory opts = {
diff --git a/tests/i915/gem_exec_latency.c b/tests/i915/gem_exec_latency.c
index 9ddb348c0..ea1eee0aa 100644
--- a/tests/i915/gem_exec_latency.c
+++ b/tests/i915/gem_exec_latency.c
@@ -109,7 +109,7 @@ poll_ring(int fd, unsigned ring, const char *name)
 	igt_spin_free(fd, spin[0]);
 }
 
-#define RCS_TIMESTAMP (0x2000 + 0x358)
+#define TIMESTAMP (0x358)
 static void latency_on_ring(int fd,
 			    unsigned ring, const char *name,
 			    unsigned flags)
@@ -119,6 +119,7 @@ static void latency_on_ring(int fd,
 	struct drm_i915_gem_exec_object2 obj[3];
 	struct drm_i915_gem_relocation_entry reloc;
 	struct drm_i915_gem_execbuffer2 execbuf;
+	const uint32_t mmio_base = gem_engine_mmio_base(fd, name);
 	igt_spin_t *spin = NULL;
 	IGT_CORK_HANDLE(c);
 	volatile uint32_t *reg;
@@ -128,7 +129,8 @@ static void latency_on_ring(int fd,
 	double gpu_latency;
 	int i, j;
 
-	reg = (volatile uint32_t *)((volatile char *)igt_global_mmio + RCS_TIMESTAMP);
+	igt_require(mmio_base);
+	reg = (volatile uint32_t *)((volatile char *)igt_global_mmio + mmio_base + TIMESTAMP);
 
 	memset(&execbuf, 0, sizeof(execbuf));
 	execbuf.buffers_ptr = to_user_pointer(&obj[1]);
@@ -176,7 +178,7 @@ static void latency_on_ring(int fd,
 		map[i++] = 0x24 << 23 | 1;
 		if (has_64bit_reloc)
 			map[i-1]++;
-		map[i++] = RCS_TIMESTAMP; /* ring local! */
+		map[i++] = mmio_base + TIMESTAMP;
 		map[i++] = offset;
 		if (has_64bit_reloc)
 			map[i++] = offset >> 32;
@@ -266,12 +268,15 @@ static void latency_from_ring(int fd,
 	struct drm_i915_gem_exec_object2 obj[3];
 	struct drm_i915_gem_relocation_entry reloc;
 	struct drm_i915_gem_execbuffer2 execbuf;
+	const uint32_t mmio_base = gem_engine_mmio_base(fd, name);
 	const unsigned int repeats = ring_size / 2;
 	unsigned int other;
 	uint32_t *map, *results;
 	uint32_t ctx[2] = {};
 	int i, j;
 
+	igt_require(mmio_base);
+
 	if (flags & PREEMPT) {
 		ctx[0] = gem_context_create(fd);
 		gem_context_set_priority(fd, ctx[0], -1023);
@@ -352,7 +357,7 @@ static void latency_from_ring(int fd,
 			map[i++] = 0x24 << 23 | 1;
 			if (has_64bit_reloc)
 				map[i-1]++;
-			map[i++] = RCS_TIMESTAMP; /* ring local! */
+			map[i++] = mmio_base + TIMESTAMP;
 			map[i++] = offset;
 			if (has_64bit_reloc)
 				map[i++] = offset >> 32;
@@ -377,7 +382,7 @@ static void latency_from_ring(int fd,
 			map[i++] = 0x24 << 23 | 1;
 			if (has_64bit_reloc)
 				map[i-1]++;
-			map[i++] = RCS_TIMESTAMP; /* ring local! */
+			map[i++] = mmio_base + TIMESTAMP;
 			map[i++] = offset;
 			if (has_64bit_reloc)
 				map[i++] = offset >> 32;
@@ -670,7 +675,7 @@ igt_main
 			ring_size = 1024;
 
 		intel_register_access_init(&mmio_data, intel_get_pci_device(), false, device);
-		rcs_clock = clockrate(device, RCS_TIMESTAMP);
+		rcs_clock = clockrate(device, 0x2000 + TIMESTAMP);
 		igt_info("RCS timestamp clock: %.0fKHz, %.1fns\n",
 			 rcs_clock / 1e3, 1e9 / rcs_clock);
 		rcs_clock = 1e9 / rcs_clock;
