[ndctl PATCH 0/3] Add CXL region passthrough >16K gran test

[ndctl PATCH 0/3] Add CXL region passthrough >16K gran test

[Alison Schofield]

A companion kernel series,
    "cxl: Allow passthrough decoders with >16K granularity",
fixes region setup for valid topologies containing passthrough
decoders beneath a wide parent interleave and extends cxl-test with a
topology that exercises the issue.

This series consolidates and simplifies the existing region creation
tests, and then adds coverage for the new topology.

Based on: https://github.com/pmem/ndctl/tree/pending

Alison Schofield (3):
  test/cxl-create-region.sh: fold in XOR region coverage
  test/cxl-create-region.sh: deduplicate decoder and memdev lookups
  test/cxl-create-region.sh: add passthrough >16K granularity test case

 test/cxl-create-region.sh | 158 ++++++++++++++++++++++++++++++++++----
 test/cxl-xor-region.sh    | 129 -------------------------------
 test/meson.build          |   2 -
 3 files changed, 144 insertions(+), 145 deletions(-)
 delete mode 100644 test/cxl-xor-region.sh


base-commit: 5fcbbee57319e718bf522436ea6595bd0f71296c
-- 
2.37.3

[ndctl PATCH 1/3] test/cxl-create-region.sh: fold in XOR region coverage

[Alison Schofield]

In the CXL Unit Test Suite, region creation coverage is split between
cxl-create-region.sh and cxl-xor-region.sh.

Consolidate the XOR coverage into cxl-create-region.sh so region
creation testing lives in one place. This avoids maintaining parallel
test infrastructure and makes it easier to add new region creation
cases.

Remove the now redundant cxl-xor-region.sh.

Continue to maintain cxl-region-sysfs.sh because it exercises the CXL
driver ABI directly.

Assisted-by: Claude:Opus-4-8
Signed-off-by: Alison Schofield <alison.schofield@intel.com>
---
 test/cxl-create-region.sh | 111 ++++++++++++++++++++++++++++++++
 test/cxl-xor-region.sh    | 129 --------------------------------------
 test/meson.build          |   2 -
 3 files changed, 111 insertions(+), 131 deletions(-)
 delete mode 100644 test/cxl-xor-region.sh

diff --git a/test/cxl-create-region.sh b/test/cxl-create-region.sh
index 658b9b8ff58a..d7a6840fed1a 100644
--- a/test/cxl-create-region.sh
+++ b/test/cxl-create-region.sh
@@ -133,6 +133,98 @@ create_single()
 	destroy_regions "$region"
 }
 
+create_and_destroy_region()
+{
+	region=$($CXL create-region -d "$decoder" -m "$memdevs" |
+		jq -r ".region")
+
+	if [[ ! $region ]]; then
+		echo "create-region failed for $decoder"
+		err "$LINENO"
+	fi
+
+	destroy_regions "$region"
+}
+
+setup_x1()
+{
+	# Find an x1 decoder
+	decoder=$($CXL list -b cxl_test -D -d root | jq -r ".[] |
+		select(.pmem_capable == true) |
+		select(.nr_targets == 1) |
+		.decoder")
+
+	# Find a memdev for this host-bridge
+	port_dev0=$($CXL list -T -d "$decoder" | jq -r ".[] |
+		.targets | .[] | select(.position == 0) | .target")
+	mem0=$($CXL list -M -p "$port_dev0" | jq -r ".[0].memdev")
+	memdevs="$mem0"
+}
+
+setup_x2()
+{
+	# Find an x2 decoder
+	decoder=$($CXL list -b cxl_test -D -d root | jq -r ".[] |
+		select(.pmem_capable == true) |
+		select(.nr_targets == 2) |
+		.decoder")
+
+	# Find a memdev for each host-bridge interleave position
+	port_dev0=$($CXL list -T -d "$decoder" | jq -r ".[] |
+		.targets | .[] | select(.position == 0) | .target")
+	port_dev1=$($CXL list -T -d "$decoder" | jq -r ".[] |
+		.targets | .[] | select(.position == 1) | .target")
+	mem0=$($CXL list -M -p "$port_dev0" | jq -r ".[0].memdev")
+	mem1=$($CXL list -M -p "$port_dev1" | jq -r ".[0].memdev")
+	memdevs="$mem0 $mem1"
+}
+
+setup_x4()
+{
+	# find an x2 decoder
+	decoder=$($CXL list -b cxl_test -D -d root | jq -r ".[] |
+		select(.pmem_capable == true) |
+		select(.nr_targets == 2) |
+		.decoder")
+
+	# Find a memdev for each host-bridge interleave position
+	port_dev0=$($CXL list -T -d "$decoder" | jq -r ".[] |
+		.targets | .[] | select(.position == 0) | .target")
+	port_dev1=$($CXL list -T -d "$decoder" | jq -r ".[] |
+		.targets | .[] | select(.position == 1) | .target")
+	mem0=$($CXL list -M -p "$port_dev0" | jq -r ".[0].memdev")
+	mem1=$($CXL list -M -p "$port_dev1" | jq -r ".[0].memdev")
+	mem2=$($CXL list -M -p "$port_dev0" | jq -r ".[1].memdev")
+	mem3=$($CXL list -M -p "$port_dev1" | jq -r ".[1].memdev")
+	memdevs="$mem0 $mem1 $mem2 $mem3"
+}
+
+setup_x3()
+{
+	# find an x3 decoder
+	decoder=$($CXL list -b cxl_test -D -d root | jq -r ".[] |
+		select(.pmem_capable == true) |
+		select(.nr_targets == 3) |
+		.decoder")
+
+	if [[ ! $decoder ]]; then
+		echo "no x3 decoder found, skipping xor-x3 test"
+		return
+	fi
+
+	# Find a memdev for each host-bridge interleave position
+	port_dev0=$($CXL list -T -d "$decoder" | jq -r ".[] |
+		.targets | .[] | select(.position == 0) | .target")
+	port_dev1=$($CXL list -T -d "$decoder" | jq -r ".[] |
+		.targets | .[] | select(.position == 1) | .target")
+	port_dev2=$($CXL list -T -d "$decoder" | jq -r ".[] |
+		.targets | .[] | select(.position == 2) | .target")
+	mem0=$($CXL list -M -p "$port_dev0" | jq -r ".[0].memdev")
+	mem1=$($CXL list -M -p "$port_dev1" | jq -r ".[0].memdev")
+	mem2=$($CXL list -M -p "$port_dev2" | jq -r ".[0].memdev")
+	memdevs="$mem0 $mem1 $mem2"
+}
+
 # test region creation on devices behind a single-port host-bridge
 create_single
 
@@ -149,6 +241,25 @@ for mem in ${mems[@]}; do
 	create_subregions "$mem"
 done
 
+# Reload cxl_test with XOR interleave arithmetic to exercise the XOR math
+# option of the CXL driver. Create x1,2,3,4 regions across the XOR roots.
+# As with the modulo tests above, changes to the CXL topology in
+# tools/testing/cxl/test/cxl.c may require an update here.
+modprobe -r cxl_test
+modprobe cxl_test interleave_arithmetic=1
+
+setup_x1
+create_and_destroy_region
+setup_x2
+create_and_destroy_region
+setup_x4
+create_and_destroy_region
+# x3 decoder may not be available in cxl/test topo yet
+setup_x3
+if [[ $decoder ]]; then
+	create_and_destroy_region
+fi
+
 check_dmesg "$LINENO"
 
 modprobe -r cxl_test
diff --git a/test/cxl-xor-region.sh b/test/cxl-xor-region.sh
deleted file mode 100644
index fb4f9a0a1515..000000000000
--- a/test/cxl-xor-region.sh
+++ /dev/null
@@ -1,129 +0,0 @@
-#!/bin/bash
-# SPDX-License-Identifier: GPL-2.0
-# Copyright (C) 2022 Intel Corporation. All rights reserved.
-
-. $(dirname $0)/common
-
-rc=77
-
-set -ex
-
-trap 'err $LINENO' ERR
-
-check_prereq "jq"
-
-modprobe -r cxl_test
-modprobe cxl_test interleave_arithmetic=1
-rc=1
-
-# THEORY OF OPERATION: Create x1,2,3,4 regions to exercise the XOR math
-# option of the CXL driver. As with other cxl_test tests, changes to the
-# CXL topology in tools/testing/cxl/test/cxl.c may require an update here.
-
-create_and_destroy_region()
-{
-	region=$($CXL create-region -d "$decoder" -m "$memdevs" |
-		jq -r ".region")
-
-	if [[ ! $region ]]; then
-		echo "create-region failed for $decoder"
-		err "$LINENO"
-	fi
-
-	$CXL destroy-region -f -b cxl_test "$region"
-}
-
-setup_x1()
-{
-	# Find an x1 decoder
-	decoder=$($CXL list -b cxl_test -D -d root | jq -r ".[] |
-		select(.pmem_capable == true) |
-		select(.nr_targets == 1) |
-		.decoder")
-
-	# Find a memdev for this host-bridge
-	port_dev0=$($CXL list -T -d "$decoder" | jq -r ".[] |
-		.targets | .[] | select(.position == 0) | .target")
-	mem0=$($CXL list -M -p "$port_dev0" | jq -r ".[0].memdev")
-	memdevs="$mem0"
-}
-
-setup_x2()
-{
-	# Find an x2 decoder
-	decoder=$($CXL list -b cxl_test -D -d root | jq -r ".[] |
-		select(.pmem_capable == true) |
-		select(.nr_targets == 2) |
-		.decoder")
-
-	# Find a memdev for each host-bridge interleave position
-	port_dev0=$($CXL list -T -d "$decoder" | jq -r ".[] |
-		.targets | .[] | select(.position == 0) | .target")
-	port_dev1=$($CXL list -T -d "$decoder" | jq -r ".[] |
-		.targets | .[] | select(.position == 1) | .target")
-	mem0=$($CXL list -M -p "$port_dev0" | jq -r ".[0].memdev")
-	mem1=$($CXL list -M -p "$port_dev1" | jq -r ".[0].memdev")
-	memdevs="$mem0 $mem1"
-}
-
-setup_x4()
-{
-	# find an x2 decoder
-	decoder=$($CXL list -b cxl_test -D -d root | jq -r ".[] |
-		select(.pmem_capable == true) |
-		select(.nr_targets == 2) |
-		.decoder")
-
-	# Find a memdev for each host-bridge interleave position
-	port_dev0=$($CXL list -T -d "$decoder" | jq -r ".[] |
-		.targets | .[] | select(.position == 0) | .target")
-	port_dev1=$($CXL list -T -d "$decoder" | jq -r ".[] |
-		.targets | .[] | select(.position == 1) | .target")
-	mem0=$($CXL list -M -p "$port_dev0" | jq -r ".[0].memdev")
-	mem1=$($CXL list -M -p "$port_dev1" | jq -r ".[0].memdev")
-	mem2=$($CXL list -M -p "$port_dev0" | jq -r ".[1].memdev")
-	mem3=$($CXL list -M -p "$port_dev1" | jq -r ".[1].memdev")
-	memdevs="$mem0 $mem1 $mem2 $mem3"
-}
-
-setup_x3()
-{
-	# find an x3 decoder
-	decoder=$($CXL list -b cxl_test -D -d root | jq -r ".[] |
-		select(.pmem_capable == true) |
-		select(.nr_targets == 3) |
-		.decoder")
-
-	if [[ ! $decoder ]]; then
-		echo "no x3 decoder found, skipping xor-x3 test"
-		return
-	fi
-
-	# Find a memdev for each host-bridge interleave position
-	port_dev0=$($CXL list -T -d "$decoder" | jq -r ".[] |
-		.targets | .[] | select(.position == 0) | .target")
-	port_dev1=$($CXL list -T -d "$decoder" | jq -r ".[] |
-		.targets | .[] | select(.position == 1) | .target")
-	port_dev2=$($CXL list -T -d "$decoder" | jq -r ".[] |
-		.targets | .[] | select(.position == 2) | .target")
-	mem0=$($CXL list -M -p "$port_dev0" | jq -r ".[0].memdev")
-	mem1=$($CXL list -M -p "$port_dev1" | jq -r ".[0].memdev")
-	mem2=$($CXL list -M -p "$port_dev2" | jq -r ".[0].memdev")
-	memdevs="$mem0 $mem1 $mem2"
-}
-
-setup_x1
-create_and_destroy_region
-setup_x2
-create_and_destroy_region
-setup_x4
-create_and_destroy_region
-# x3 decoder may not be available in cxl/test topo yet
-setup_x3
-if [[ $decoder ]]; then
-	create_and_destroy_region
-fi
-
-check_dmesg "$LINENO"
-
-modprobe -r cxl_test
diff --git a/test/meson.build b/test/meson.build
index 56aed9cc3c9d..5729d26d2a31 100644
--- a/test/meson.build
+++ b/test/meson.build
@@ -161,7 +161,6 @@ cxl_topo = find_program('cxl-topology.sh')
 cxl_sysfs = find_program('cxl-region-sysfs.sh')
 cxl_labels = find_program('cxl-labels.sh')
 cxl_create_region = find_program('cxl-create-region.sh')
-cxl_xor_region = find_program('cxl-xor-region.sh')
 cxl_update_firmware = find_program('cxl-update-firmware.sh')
 cxl_events = find_program('cxl-events.sh')
 cxl_sanitize = find_program('cxl-sanitize.sh')
@@ -198,7 +197,6 @@ tests = [
   [ 'cxl-region-sysfs.sh',    cxl_sysfs,	  'cxl'   ],
   [ 'cxl-labels.sh',          cxl_labels,	  'cxl'   ],
   [ 'cxl-create-region.sh',   cxl_create_region,  'cxl'   ],
-  [ 'cxl-xor-region.sh',      cxl_xor_region,     'cxl'   ],
   [ 'cxl-events.sh',          cxl_events,         'cxl'   ],
   [ 'cxl-sanitize.sh',        cxl_sanitize,       'cxl'   ],
   [ 'cxl-destroy-region.sh',  cxl_destroy_region, 'cxl'   ],
-- 
2.37.3

[ndctl PATCH 2/3] test/cxl-create-region.sh: deduplicate decoder and memdev lookups

[Alison Schofield]

Several region setup helpers open-code the same decoder and memdev
lookups.

Factor the common queries into shared helpers. This reduces duplicate
logic and simplifies adding new region configuration tests.

No functional change.

Assisted-by: Claude:Opus-4-8
Signed-off-by: Alison Schofield <alison.schofield@intel.com>
---
 test/cxl-create-region.sh | 73 ++++++++++++++++++---------------------
 1 file changed, 33 insertions(+), 40 deletions(-)

diff --git a/test/cxl-create-region.sh b/test/cxl-create-region.sh
index d7a6840fed1a..5941e18f338d 100644
--- a/test/cxl-create-region.sh
+++ b/test/cxl-create-region.sh
@@ -25,17 +25,21 @@ destroy_regions()
 	fi
 }
 
+# Find the pmem capable single-target root decoder for a memdev
+find_x1_decoder()
+{
+	$CXL list -b cxl_test -D -d root -m "$1" |
+		  jq -r ".[] |
+		  select(.pmem_capable == true) |
+		  select(.nr_targets == 1) |
+		  .decoder"
+}
+
 create_x1_region()
 {
 	mem="$1"
 
-	# find a pmem capable root decoder for this mem
-	decoder=$($CXL list -b cxl_test -D -d root -m "$mem" |
-		  jq -r ".[] |
-		  select(.pmem_capable == true) |
-		  select(.nr_targets == 1) |
-		  .decoder")
-
+	decoder=$(find_x1_decoder "$mem")
 	if [[ ! $decoder ]]; then
 		echo "no suitable decoder found for $mem, skipping"
 		return
@@ -69,13 +73,7 @@ create_subregions()
 	slice=$((256 << 20))
 	mem="$1"
 
-	# find a pmem capable root decoder for this mem
-	decoder=$($CXL list -b cxl_test -D -d root -m "$mem" |
-		  jq -r ".[] |
-		  select(.pmem_capable == true) |
-		  select(.nr_targets == 1) |
-		  .decoder")
-
+	decoder=$(find_x1_decoder "$mem")
 	if [[ ! $decoder ]]; then
 		echo "no suitable decoder found for $mem, skipping"
 		return
@@ -133,6 +131,17 @@ create_single()
 	destroy_regions "$region"
 }
 
+# Find the index'th memdev behind the decoder's target at position
+find_memdev()
+{
+	local decoder="$1" position="$2" index="$3"
+	local port_dev
+
+	port_dev=$($CXL list -T -d "$decoder" | jq -r ".[] |
+		.targets | .[] | select(.position == $position) | .target")
+	$CXL list -M -p "$port_dev" | jq -r ".[$index].memdev"
+}
+
 create_and_destroy_region()
 {
 	region=$($CXL create-region -d "$decoder" -m "$memdevs" |
@@ -155,9 +164,7 @@ setup_x1()
 		.decoder")
 
 	# Find a memdev for this host-bridge
-	port_dev0=$($CXL list -T -d "$decoder" | jq -r ".[] |
-		.targets | .[] | select(.position == 0) | .target")
-	mem0=$($CXL list -M -p "$port_dev0" | jq -r ".[0].memdev")
+	mem0=$(find_memdev "$decoder" 0 0)
 	memdevs="$mem0"
 }
 
@@ -170,12 +177,8 @@ setup_x2()
 		.decoder")
 
 	# Find a memdev for each host-bridge interleave position
-	port_dev0=$($CXL list -T -d "$decoder" | jq -r ".[] |
-		.targets | .[] | select(.position == 0) | .target")
-	port_dev1=$($CXL list -T -d "$decoder" | jq -r ".[] |
-		.targets | .[] | select(.position == 1) | .target")
-	mem0=$($CXL list -M -p "$port_dev0" | jq -r ".[0].memdev")
-	mem1=$($CXL list -M -p "$port_dev1" | jq -r ".[0].memdev")
+	mem0=$(find_memdev "$decoder" 0 0)
+	mem1=$(find_memdev "$decoder" 1 0)
 	memdevs="$mem0 $mem1"
 }
 
@@ -188,14 +191,10 @@ setup_x4()
 		.decoder")
 
 	# Find a memdev for each host-bridge interleave position
-	port_dev0=$($CXL list -T -d "$decoder" | jq -r ".[] |
-		.targets | .[] | select(.position == 0) | .target")
-	port_dev1=$($CXL list -T -d "$decoder" | jq -r ".[] |
-		.targets | .[] | select(.position == 1) | .target")
-	mem0=$($CXL list -M -p "$port_dev0" | jq -r ".[0].memdev")
-	mem1=$($CXL list -M -p "$port_dev1" | jq -r ".[0].memdev")
-	mem2=$($CXL list -M -p "$port_dev0" | jq -r ".[1].memdev")
-	mem3=$($CXL list -M -p "$port_dev1" | jq -r ".[1].memdev")
+	mem0=$(find_memdev "$decoder" 0 0)
+	mem1=$(find_memdev "$decoder" 1 0)
+	mem2=$(find_memdev "$decoder" 0 1)
+	mem3=$(find_memdev "$decoder" 1 1)
 	memdevs="$mem0 $mem1 $mem2 $mem3"
 }
 
@@ -213,15 +212,9 @@ setup_x3()
 	fi
 
 	# Find a memdev for each host-bridge interleave position
-	port_dev0=$($CXL list -T -d "$decoder" | jq -r ".[] |
-		.targets | .[] | select(.position == 0) | .target")
-	port_dev1=$($CXL list -T -d "$decoder" | jq -r ".[] |
-		.targets | .[] | select(.position == 1) | .target")
-	port_dev2=$($CXL list -T -d "$decoder" | jq -r ".[] |
-		.targets | .[] | select(.position == 2) | .target")
-	mem0=$($CXL list -M -p "$port_dev0" | jq -r ".[0].memdev")
-	mem1=$($CXL list -M -p "$port_dev1" | jq -r ".[0].memdev")
-	mem2=$($CXL list -M -p "$port_dev2" | jq -r ".[0].memdev")
+	mem0=$(find_memdev "$decoder" 0 0)
+	mem1=$(find_memdev "$decoder" 1 0)
+	mem2=$(find_memdev "$decoder" 2 0)
 	memdevs="$mem0 $mem1 $mem2"
 }
 
-- 
2.37.3

[ndctl PATCH 3/3] test/cxl-create-region.sh: add passthrough >16K granularity test case

[Alison Schofield]

The CXL driver region configuration use to reject valid topologies
containing passthrough decoders beneath a wide parent interleave.
A recent kernel patch fixed that issue and extended cxl-test with
a topology that exercises it.

Add a create-and-destroy region case spanning the two host bridges
beneath the new 2-way 16K root decoder to verify that such
configurations are accepted.

The test case is quietly skipped if the new cxl/test topology is
not found, which also means the kernel fix is not yet present.

Assisted-by: Claude:Opus-4-8
Signed-off-by: Alison Schofield <alison.schofield@intel.com>
---
 test/cxl-create-region.sh | 30 ++++++++++++++++++++++++++++--
 1 file changed, 28 insertions(+), 2 deletions(-)

diff --git a/test/cxl-create-region.sh b/test/cxl-create-region.sh
index 5941e18f338d..c24e477c4f5c 100644
--- a/test/cxl-create-region.sh
+++ b/test/cxl-create-region.sh
@@ -170,10 +170,12 @@ setup_x1()
 
 setup_x2()
 {
-	# Find an x2 decoder
+	# Find an x2 decoder. Pin to the 256 granularity root to avoid
+	# the 16K root used by the passthrough granularity test.
 	decoder=$($CXL list -b cxl_test -D -d root | jq -r ".[] |
 		select(.pmem_capable == true) |
 		select(.nr_targets == 2) |
+		select(.interleave_granularity == 256) |
 		.decoder")
 
 	# Find a memdev for each host-bridge interleave position
@@ -184,10 +186,12 @@ setup_x2()
 
 setup_x4()
 {
-	# find an x2 decoder
+	# find an x2 decoder. Pin to the 256 granularity root to avoid
+	# the 16K root used by the passthrough granularity test.
 	decoder=$($CXL list -b cxl_test -D -d root | jq -r ".[] |
 		select(.pmem_capable == true) |
 		select(.nr_targets == 2) |
+		select(.interleave_granularity == 256) |
 		.decoder")
 
 	# Find a memdev for each host-bridge interleave position
@@ -198,6 +202,23 @@ setup_x4()
 	memdevs="$mem0 $mem1 $mem2 $mem3"
 }
 
+setup_passthru_gran()
+{
+	# Find the 2-way 16K root. A region spanning both host bridges
+	# places one endpoint under each. The intermediate switch decoders
+	# are passthrough decoders with 32K granularity.
+	decoder=$($CXL list -b cxl_test -D -d root | jq -r ".[] |
+		select(.pmem_capable == true) |
+		select(.nr_targets == 2) |
+		select(.interleave_granularity == 16384) |
+		.decoder")
+
+	# Find a memdev for each host-bridge interleave position
+	mem0=$(find_memdev "$decoder" 0 0)
+	mem1=$(find_memdev "$decoder" 1 0)
+	memdevs="$mem0 $mem1"
+}
+
 setup_x3()
 {
 	# find an x3 decoder
@@ -252,6 +273,11 @@ setup_x3
 if [[ $decoder ]]; then
 	create_and_destroy_region
 fi
+# 16K root may not be available in cxl/test topo yet
+setup_passthru_gran
+if [[ $decoder ]]; then
+	create_and_destroy_region
+fi
 
 check_dmesg "$LINENO"
 
-- 
2.37.3