[PATCH v5 00/17] Device tree based NUMA support for Arm - Part#3

[PATCH v5 00/17] Device tree based NUMA support for Arm - Part#3

[Henry Wang]

(Henry: Following the offline discussion with Wei, I will be
the one to follow-up the upstream comments for this series.)

The preparation work to support NUMA on Arm has been merged
and can be found at [1] and [2]. The initial discussions of
the Arm NUMA support can be found at [3].

- Background of this series:

Xen memory allocation and scheduler modules are NUMA aware.
But actually, on x86 has implemented the architecture APIs
to support NUMA. Arm was providing a set of fake architecture
APIs to make it compatible with NUMA awared memory allocation
and scheduler.

Arm system was working well as a single node NUMA system with
these fake APIs, because we didn't have multiple nodes NUMA
system on Arm. But in recent years, more and more Arm devices
support multiple nodes NUMA system.

So now we have a new problem. When Xen is running on these Arm
devices, Xen still treat them as single node SMP systems. The
NUMA affinity capability of Xen memory allocation and scheduler
becomes meaningless. Because they rely on input data that does
not reflect real NUMA layout.

Xen still think the access time for all of the memory is the
same for all CPUs. However, Xen may allocate memory to a VM
from different NUMA nodes with different access speeds. This
difference can be amplified in workloads inside VM, causing
performance instability and timeouts.

So in this patch series, we implement a set of NUMA API to use
device tree to describe the NUMA layout. We reuse most of the
code of x86 NUMA to create and maintain the mapping between
memory and CPU, create the matrix between any two NUMA nodes.
Except ACPI and some x86 specified code, we have moved other
code to common. In next stage, when we implement ACPI based
NUMA for Arm64, we may move the ACPI NUMA code to common too,
but in current stage, we keep it as x86 only.

This patch serires has been tested and booted well on FVP in
Arm64 mode with NUMA configs in device tree and one HPE x86
NUMA machine.

[1] https://lists.xenproject.org/archives/html/xen-devel/2022-06/msg00499.html
[2] https://lists.xenproject.org/archives/html/xen-devel/2022-11/msg01043.html
[3] https://lists.xenproject.org/archives/html/xen-devel/2021-09/msg01903.html

v4 -> v5:
1. Coding style (extra blank line, label indentation and printk variable
   type) and in-code comment fixes and improvements.
2. Move the from/to range check in numa_set_distance() to caller,
   Drop the unnecessary check ensured by caller in numa_set_distance().
3. Rework the invalid distance check in numa_set_distance() following
   Linux, add more in-code comments about these distance checks.
4. Rename "numa_device_tree.c" to "numa-dt.c".
5. Check the from/to range to avoid the side-effect of the 8-bit
   truncation by numa_set_distance().

v3 -> v4:
1. s/definition/declaration/ in commit message.
2. Add Acked-by tag from Jan for non-Arm parts.
3. Drop unnecessary initializer for node_distance_map. Pre-set the
   distance map to NUMA_NO_DISTANCE.
4. Drop NUMA_DISTANCE_UDF_MIN and its usage.
5. Drop EXPORT_SYMBOL(__node_distance).
6. Rework __node_distance()'s return value logic.
7. The distance map default value is now NUMA_NO_DISTANCE, update
   the logic accordingly and add in-code comment as a note.
8. Add Acked-by tag from Jan for related patches.

Henry Wang (1):
  xen/arm: Set correct per-cpu cpu_core_mask

Wei Chen (16):
  xen/arm: use NR_MEM_BANKS to override default NR_NODE_MEMBLKS
  xen/arm: implement helpers to get and update NUMA status
  xen/arm: implement node distance helpers for Arm
  xen/arm: use arch_get_ram_range to get memory ranges from bootinfo
  xen/arm: build NUMA cpu_to_node map in dt_smp_init_cpus
  xen/arm: Add boot and secondary CPU to NUMA system
  xen/arm: introduce a helper to parse device tree processor node
  xen/arm: introduce a helper to parse device tree memory node
  xen/arm: introduce a helper to parse device tree NUMA distance map
  xen/arm: unified entry to parse all NUMA data from device tree
  xen/arm: keep guest still be NUMA unware
  xen/arm: enable device tree based NUMA in system init
  xen/arm: implement numa_node_to_arch_nid for device tree NUMA
  xen/arm: use CONFIG_NUMA to gate node_online_map in smpboot
  xen/arm: Provide Kconfig options for Arm to enable NUMA
  docs: update numa command line to support Arm

 SUPPORT.md                        |   1 +
 docs/misc/xen-command-line.pandoc |   2 +-
 xen/arch/arm/Kconfig              |  11 ++
 xen/arch/arm/Makefile             |   2 +
 xen/arch/arm/domain_build.c       |   6 +
 xen/arch/arm/include/asm/numa.h   |  91 ++++++++-
 xen/arch/arm/numa-dt.c            | 299 ++++++++++++++++++++++++++++++
 xen/arch/arm/numa.c               | 184 ++++++++++++++++++
 xen/arch/arm/setup.c              |  17 ++
 xen/arch/arm/smpboot.c            |  38 ++++
 xen/arch/x86/include/asm/numa.h   |   1 -
 xen/arch/x86/srat.c               |   2 +-
 xen/include/xen/numa.h            |  10 +
 13 files changed, 660 insertions(+), 4 deletions(-)
 create mode 100644 xen/arch/arm/numa-dt.c
 create mode 100644 xen/arch/arm/numa.c

-- 
2.25.1

[PATCH v5 01/17] xen/arm: use NR_MEM_BANKS to override default NR_NODE_MEMBLKS

[Henry Wang]

From: Wei Chen <wei.chen@arm.com>

As a memory range described in device tree cannot be split across
multiple nodes. And it is very likely than if you have more than
64 nodes, you may need a lot more than 2 regions per node. So the
default NR_NODE_MEMBLKS value (MAX_NUMNODES * 2) makes no sense
on Arm.

So, for Arm, we would just define NR_NODE_MEMBLKS as an alias to
NR_MEM_BANKS. And in the future NR_MEM_BANKS will be user-configurable
via kconfig, but for now leave NR_MEM_BANKS as 128 on Arm. This
avoids having different way to define the value based NUMA vs non-NUMA.

Further discussions can be found here[1].

[1] https://lists.xenproject.org/archives/html/xen-devel/2021-09/msg02322.html

Signed-off-by: Wei Chen <wei.chen@arm.com>
Signed-off-by: Henry Wang <Henry.Wang@arm.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
---
v4 -> v5:
1. No change.
v3 -> v4:
1. Add Acked-by tag from Jan.
v2 -> v3:
By checking the discussion in [1] and [2]
[1] https://lists.xenproject.org/archives/html/xen-devel/2023-01/msg00595.html
[2] https://lists.xenproject.org/archives/html/xen-devel/2021-09/msg02322.html
1. No change
v1 -> v2:
1. Add code comments to explain using NR_MEM_BANKS for Arm
2. Refine commit messages.
---
 xen/arch/arm/include/asm/numa.h | 19 ++++++++++++++++++-
 xen/include/xen/numa.h          |  9 +++++++++
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/xen/arch/arm/include/asm/numa.h b/xen/arch/arm/include/asm/numa.h
index e2bee2bd82..7d6ae36a19 100644
--- a/xen/arch/arm/include/asm/numa.h
+++ b/xen/arch/arm/include/asm/numa.h
@@ -3,9 +3,26 @@
 
 #include <xen/mm.h>
 
+#include <asm/setup.h>
+
 typedef u8 nodeid_t;
 
-#ifndef CONFIG_NUMA
+#ifdef CONFIG_NUMA
+
+/*
+ * It is very likely that if you have more than 64 nodes, you may
+ * need a lot more than 2 regions per node. So, for Arm, we would
+ * just define NR_NODE_MEMBLKS as an alias to NR_MEM_BANKS.
+ * And in the future NR_MEM_BANKS will be bumped for new platforms,
+ * but for now leave NR_MEM_BANKS as it is on Arm. This avoid to
+ * have different way to define the value based NUMA vs non-NUMA.
+ *
+ * Further discussions can be found here:
+ * https://lists.xenproject.org/archives/html/xen-devel/2021-09/msg02322.html
+ */
+#define NR_NODE_MEMBLKS NR_MEM_BANKS
+
+#else
 
 /* Fake one node for now. See also node_online_map. */
 #define cpu_to_node(cpu) 0
diff --git a/xen/include/xen/numa.h b/xen/include/xen/numa.h
index 29b8c2df89..b86d0851fc 100644
--- a/xen/include/xen/numa.h
+++ b/xen/include/xen/numa.h
@@ -13,7 +13,16 @@
 #define MAX_NUMNODES 1
 #endif
 
+/*
+ * Some architectures may have different considerations for
+ * number of node memory blocks. They can define their
+ * NR_NODE_MEMBLKS in asm/numa.h to reflect their architectural
+ * implementation. If the arch does not have specific implementation,
+ * the following default NR_NODE_MEMBLKS will be used.
+ */
+#ifndef NR_NODE_MEMBLKS
 #define NR_NODE_MEMBLKS (MAX_NUMNODES * 2)
+#endif
 
 #define vcpu_to_node(v) (cpu_to_node((v)->processor))
 
-- 
2.25.1

[PATCH v5 02/17] xen/arm: implement helpers to get and update NUMA status

[Henry Wang]

From: Wei Chen <wei.chen@arm.com>

NUMA has one global and one implementation specific switches. For
ACPI NUMA implementation, Xen has acpi_numa, so we introduce
device_tree_numa for device tree NUMA implementation. And use
enumerations to indicate init, off and on status.

arch_numa_disabled will get device_tree_numa status, but for
arch_numa_setup we have not provided boot arguments to setup
device_tree_numa. So we just return -EINVAL in this patch.

Signed-off-by: Wei Chen <wei.chen@arm.com>
Signed-off-by: Henry Wang <Henry.Wang@arm.com>
---
v4 -> v5:
1. No change.
v3 -> v4:
1. No change.
v2 -> v3:
1. Rename the first entry of enum dt_numa_status as DT_NUMA_DEFAULT.
2. Make enum dt_numa_status device_tree_numa as __ro_after_init and
   assign it explicitly to DT_NUMA_DEFAULT.
3. Update the year in copyright to 2023.
4. Don't move the x86 numa_disabled() and make Arm's numa_disabled()
   a static inline function for !CONFIG_NUMA.
v1 -> v2:
1. Use arch_numa_disabled to replace numa_enable_with_firmware.
2. Introduce enumerations for device tree numa status.
3. Use common numa_disabled, drop Arm version numa_disabled.
4. Introduce arch_numa_setup for Arm.
5. Rename bad_srat to numa_bad.
6. Add numa_enable_with_firmware helper.
7. Add numa_disabled helper.
8. Refine commit message.
---
 xen/arch/arm/include/asm/numa.h | 17 +++++++++++
 xen/arch/arm/numa.c             | 50 +++++++++++++++++++++++++++++++++
 2 files changed, 67 insertions(+)
 create mode 100644 xen/arch/arm/numa.c

diff --git a/xen/arch/arm/include/asm/numa.h b/xen/arch/arm/include/asm/numa.h
index 7d6ae36a19..83f60ad05b 100644
--- a/xen/arch/arm/include/asm/numa.h
+++ b/xen/arch/arm/include/asm/numa.h
@@ -22,6 +22,8 @@ typedef u8 nodeid_t;
  */
 #define NR_NODE_MEMBLKS NR_MEM_BANKS
 
+extern bool numa_disabled(void);
+
 #else
 
 /* Fake one node for now. See also node_online_map. */
@@ -39,6 +41,21 @@ extern mfn_t first_valid_mfn;
 #define node_start_pfn(nid) (mfn_x(first_valid_mfn))
 #define __node_distance(a, b) (20)
 
+static inline bool numa_disabled(void)
+{
+    return true;
+}
+
+static inline bool arch_numa_unavailable(void)
+{
+    return true;
+}
+
+static inline bool arch_numa_broken(void)
+{
+    return true;
+}
+
 #endif
 
 #define arch_want_default_dmazone() (false)
diff --git a/xen/arch/arm/numa.c b/xen/arch/arm/numa.c
new file mode 100644
index 0000000000..eb5d0632cb
--- /dev/null
+++ b/xen/arch/arm/numa.c
@@ -0,0 +1,50 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Arm Architecture support layer for NUMA.
+ *
+ * Copyright (C) 2023 Arm Ltd
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+#include <xen/init.h>
+#include <xen/numa.h>
+
+enum dt_numa_status {
+    DT_NUMA_DEFAULT,
+    DT_NUMA_ON,
+    DT_NUMA_OFF,
+};
+
+static enum dt_numa_status __ro_after_init device_tree_numa = DT_NUMA_DEFAULT;
+
+void __init numa_fw_bad(void)
+{
+    printk(KERN_ERR "NUMA: device tree numa info table not used.\n");
+    device_tree_numa = DT_NUMA_OFF;
+}
+
+bool __init arch_numa_unavailable(void)
+{
+    return device_tree_numa != DT_NUMA_ON;
+}
+
+bool arch_numa_disabled(void)
+{
+    return device_tree_numa == DT_NUMA_OFF;
+}
+
+int __init arch_numa_setup(const char *opt)
+{
+    return -EINVAL;
+}
-- 
2.25.1

[PATCH v5 03/17] xen/arm: implement node distance helpers for Arm

[Henry Wang]

From: Wei Chen <wei.chen@arm.com>

We will parse NUMA nodes distances from device tree. So we need
a matrix to record the distances between any two nodes we parsed.
Accordingly, we provide this node_set_distance API for device tree
NUMA to set the distance for any two nodes in this patch. When
NUMA initialization failed, __node_distance will return
NUMA_REMOTE_DISTANCE, this will help us avoid doing rollback
for distance maxtrix when NUMA initialization failed.

As both x86 and Arm have implemented __node_distance, so we move
its declaration from asm/numa.h to xen/numa.h. At same time, the
outdated u8 return value of x86 has been changed to unsigned char.

Signed-off-by: Wei Chen <wei.chen@arm.com>
Signed-off-by: Henry Wang <Henry.Wang@arm.com>
Acked-by: Jan Beulich <jbeulich@suse.com> # non-Arm parts
---
v4 -> v5:
1. Coding style (extra blank line and printk variable type) and
   in-code comment fixes and improvements.
2. Move the from/to range check in numa_set_distance() to caller,
   Drop the unnecessary check ensured by caller in numa_set_distance().
3. Rework the invalid distance check in numa_set_distance() following
   Linux, add more in-code comments about these distance checks.
v3 -> v4:
1. s/definition/declaration/ in commit message.
2. Add Acked-by tag from Jan for non-Arm parts.
3. Drop unnecessary initializer for node_distance_map. Pre-set the
   distance map to NUMA_NO_DISTANCE.
4. Drop NUMA_DISTANCE_UDF_MIN and its usage.
5. Drop EXPORT_SYMBOL(__node_distance).
6. Rework __node_distance()'s return value logic.
v2 -> v3:
1. Use __ro_after_init for node_distance_map.
2. Correct format of if condition identation in numa_set_distance().
3. Drop the unnecessary change to the year of copyright.
4. Use ARRAY_SIZE() to determine node_distance_map's row, column size.
v1 -> v2:
1. Use unsigned int/char instead of uint32_t/u8.
2. Re-org the commit message.
---
 xen/arch/arm/Makefile           |  1 +
 xen/arch/arm/include/asm/numa.h | 12 ++++++++
 xen/arch/arm/numa.c             | 51 +++++++++++++++++++++++++++++++++
 xen/arch/x86/include/asm/numa.h |  1 -
 xen/arch/x86/srat.c             |  2 +-
 xen/include/xen/numa.h          |  1 +
 6 files changed, 66 insertions(+), 2 deletions(-)

diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile
index d85fc040df..814c472c4f 100644
--- a/xen/arch/arm/Makefile
+++ b/xen/arch/arm/Makefile
@@ -38,6 +38,7 @@ obj-$(CONFIG_LIVEPATCH) += livepatch.o
 obj-y += mem_access.o
 obj-y += mm.o
 obj-y += monitor.o
+obj-$(CONFIG_NUMA) += numa.o
 obj-y += p2m.o
 obj-y += percpu.o
 obj-y += platform.o
diff --git a/xen/arch/arm/include/asm/numa.h b/xen/arch/arm/include/asm/numa.h
index 83f60ad05b..96c856a9f7 100644
--- a/xen/arch/arm/include/asm/numa.h
+++ b/xen/arch/arm/include/asm/numa.h
@@ -22,7 +22,19 @@ typedef u8 nodeid_t;
  */
 #define NR_NODE_MEMBLKS NR_MEM_BANKS
 
+/*
+ * In ACPI spec, 0-9 are the reserved values for node distance,
+ * 10 indicates local node distance, 20 indicates remote node
+ * distance. Set node distance map in device tree will follow
+ * the ACPI's definition.
+ */
+#define NUMA_DISTANCE_UDF_MAX   9
+#define NUMA_LOCAL_DISTANCE     10
+#define NUMA_REMOTE_DISTANCE    20
+
 extern bool numa_disabled(void);
+extern void numa_set_distance(nodeid_t from, nodeid_t to,
+                              unsigned int distance);
 
 #else
 
diff --git a/xen/arch/arm/numa.c b/xen/arch/arm/numa.c
index eb5d0632cb..31332a6ea7 100644
--- a/xen/arch/arm/numa.c
+++ b/xen/arch/arm/numa.c
@@ -28,6 +28,11 @@ enum dt_numa_status {
 
 static enum dt_numa_status __ro_after_init device_tree_numa = DT_NUMA_DEFAULT;
 
+static unsigned char __ro_after_init
+node_distance_map[MAX_NUMNODES][MAX_NUMNODES] = {
+    [0 ... MAX_NUMNODES - 1] = { [0 ... MAX_NUMNODES - 1] = NUMA_NO_DISTANCE }
+};
+
 void __init numa_fw_bad(void)
 {
     printk(KERN_ERR "NUMA: device tree numa info table not used.\n");
@@ -48,3 +53,49 @@ int __init arch_numa_setup(const char *opt)
 {
     return -EINVAL;
 }
+
+void __init numa_set_distance(nodeid_t from, nodeid_t to,
+                              unsigned int distance)
+{
+    /*
+     * Since the NUMA device tree binding does not clearly specify the valid
+     * range of node distance, here we keep consistent with the ACPI, whose
+     * SLIT table uses 1 byte to describe the node distance. Hence node
+     * distances that cannot fit in 1 byte are invalid. Also, node distance
+     * 0-9 are undefined values.
+     * Reject all above-mentioned invalid distance values.
+     */
+    if ( (uint8_t)distance != distance || distance <= NUMA_DISTANCE_UDF_MAX )
+    {
+        printk(XENLOG_WARNING
+               "NUMA: invalid distance: from=%"PRIu8" to=%"PRIu8" distance=%u\n",
+               from, to, distance);
+        return;
+    }
+
+    node_distance_map[from][to] = distance;
+}
+
+unsigned char __node_distance(nodeid_t from, nodeid_t to)
+{
+    if ( from == to )
+        return NUMA_LOCAL_DISTANCE;
+
+    /*
+     * When NUMA is off, any distance will be treated as unreachable, so
+     * directly return NUMA_NO_DISTANCE from here as an optimization.
+     */
+    if ( numa_disabled() )
+        return NUMA_NO_DISTANCE;
+
+    /*
+     * Check whether the nodes are in the matrix range.
+     * When any node is out of range, except from and to nodes are the
+     * same (see above), we treat them as unreachable.
+     */
+    if ( from >= ARRAY_SIZE(node_distance_map) ||
+         to >= ARRAY_SIZE(node_distance_map[0]) )
+        return NUMA_NO_DISTANCE;
+
+    return node_distance_map[from][to];
+}
diff --git a/xen/arch/x86/include/asm/numa.h b/xen/arch/x86/include/asm/numa.h
index 7866afa408..45456ac441 100644
--- a/xen/arch/x86/include/asm/numa.h
+++ b/xen/arch/x86/include/asm/numa.h
@@ -22,7 +22,6 @@ extern void init_cpu_to_node(void);
 #define arch_want_default_dmazone() (num_online_nodes() > 1)
 
 void srat_parse_regions(paddr_t addr);
-extern u8 __node_distance(nodeid_t a, nodeid_t b);
 unsigned int arch_get_dma_bitsize(void);
 
 #endif
diff --git a/xen/arch/x86/srat.c b/xen/arch/x86/srat.c
index 56749ddca5..50faf5d352 100644
--- a/xen/arch/x86/srat.c
+++ b/xen/arch/x86/srat.c
@@ -328,7 +328,7 @@ unsigned int numa_node_to_arch_nid(nodeid_t n)
 	return 0;
 }
 
-u8 __node_distance(nodeid_t a, nodeid_t b)
+unsigned char __node_distance(nodeid_t a, nodeid_t b)
 {
 	unsigned index;
 	u8 slit_val;
diff --git a/xen/include/xen/numa.h b/xen/include/xen/numa.h
index b86d0851fc..8356e47b61 100644
--- a/xen/include/xen/numa.h
+++ b/xen/include/xen/numa.h
@@ -114,6 +114,7 @@ extern bool numa_memblks_available(void);
 extern bool numa_update_node_memblks(nodeid_t node, unsigned int arch_nid,
                                      paddr_t start, paddr_t size, bool hotplug);
 extern void numa_set_processor_nodes_parsed(nodeid_t node);
+extern unsigned char __node_distance(nodeid_t a, nodeid_t b);
 
 #else
 
-- 
2.25.1

[PATCH v5 04/17] xen/arm: use arch_get_ram_range to get memory ranges from bootinfo

[Henry Wang]

From: Wei Chen <wei.chen@arm.com>

Implement the same helper "arch_get_ram_range" as x86 for NUMA
code to get memory bank from Arm bootinfo.

Signed-off-by: Wei Chen <wei.chen@arm.com>
Signed-off-by: Henry Wang <Henry.Wang@arm.com>
---
v4 -> v5:
1. No change.
v3 -> v4:
1. No change.
v2 -> v3:
1. No change.
v1 -> v2:
1. Use arch_get_ram_range instead of arch_get_memory_map.
---
 xen/arch/arm/numa.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/xen/arch/arm/numa.c b/xen/arch/arm/numa.c
index 31332a6ea7..e9b2ec93bc 100644
--- a/xen/arch/arm/numa.c
+++ b/xen/arch/arm/numa.c
@@ -99,3 +99,14 @@ unsigned char __node_distance(nodeid_t from, nodeid_t to)
 
     return node_distance_map[from][to];
 }
+
+int __init arch_get_ram_range(unsigned int idx, paddr_t *start, paddr_t *end)
+{
+    if ( idx >= bootinfo.mem.nr_banks )
+        return -ENOENT;
+
+    *start = bootinfo.mem.bank[idx].start;
+    *end = *start + bootinfo.mem.bank[idx].size;
+
+    return 0;
+}
-- 
2.25.1

[PATCH v5 05/17] xen/arm: build NUMA cpu_to_node map in dt_smp_init_cpus

[Henry Wang]

From: Wei Chen <wei.chen@arm.com>

NUMA implementation has a cpu_to_node array to store CPU to NODE
map. Xen is using CPU logical ID in runtime components, so we
use CPU logical ID as CPU index in cpu_to_node.

In device tree case, cpu_logical_map is created in dt_smp_init_cpus.
So, when NUMA is enabled, dt_smp_init_cpus will fetch CPU NUMA id
at the same time for cpu_to_node.

Signed-off-by: Wei Chen <wei.chen@arm.com>
Signed-off-by: Henry Wang <Henry.Wang@arm.com>
---
v4 -> v5:
1. No change.
v3 -> v4:
1. No change.
v2 -> v3:
1. No change.
v1 -> v2:
1. Use static inline to replace macros to perform
   function paramerters type check.
2. Add numa_disabled to gate the numa-node-id check for
   CONFIG_NUMA on but numa disabled user case.
3. Use macro instead of static inline function to stub
   numa_set_node.
---
 xen/arch/arm/include/asm/numa.h |  4 ++++
 xen/arch/arm/smpboot.c          | 36 +++++++++++++++++++++++++++++++++
 2 files changed, 40 insertions(+)

diff --git a/xen/arch/arm/include/asm/numa.h b/xen/arch/arm/include/asm/numa.h
index 96c856a9f7..97d4a67dea 100644
--- a/xen/arch/arm/include/asm/numa.h
+++ b/xen/arch/arm/include/asm/numa.h
@@ -68,6 +68,10 @@ static inline bool arch_numa_broken(void)
     return true;
 }
 
+static inline void numa_set_node(unsigned int cpu, nodeid_t node)
+{
+}
+
 #endif
 
 #define arch_want_default_dmazone() (false)
diff --git a/xen/arch/arm/smpboot.c b/xen/arch/arm/smpboot.c
index e107b86b7b..7506085540 100644
--- a/xen/arch/arm/smpboot.c
+++ b/xen/arch/arm/smpboot.c
@@ -118,7 +118,12 @@ static void __init dt_smp_init_cpus(void)
     {
         [0 ... NR_CPUS - 1] = MPIDR_INVALID
     };
+    static nodeid_t node_map[NR_CPUS] __initdata =
+    {
+        [0 ... NR_CPUS - 1] = NUMA_NO_NODE
+    };
     bool bootcpu_valid = false;
+    unsigned int nid = 0;
     int rc;
 
     mpidr = system_cpuinfo.mpidr.bits & MPIDR_HWID_MASK;
@@ -169,6 +174,28 @@ static void __init dt_smp_init_cpus(void)
             continue;
         }
 
+        if ( IS_ENABLED(CONFIG_NUMA) )
+        {
+            /*
+             * When CONFIG_NUMA is set, try to fetch numa infomation
+             * from CPU dts node, otherwise the nid is always 0.
+             */
+            if ( !dt_property_read_u32(cpu, "numa-node-id", &nid) )
+            {
+                printk(XENLOG_WARNING
+                       "cpu[%d] dts path: %s: doesn't have numa information!\n",
+                       cpuidx, dt_node_full_name(cpu));
+                /*
+                 * During the early stage of NUMA initialization, when Xen
+                 * found any CPU dts node doesn't have numa-node-id info, the
+                 * NUMA will be treated as off, all CPU will be set to a FAKE
+                 * node 0. So if we get numa-node-id failed here, we should
+                 * set nid to 0.
+                 */
+                nid = 0;
+            }
+        }
+
         /*
          * 8 MSBs must be set to 0 in the DT since the reg property
          * defines the MPIDR[23:0]
@@ -228,9 +255,13 @@ static void __init dt_smp_init_cpus(void)
         {
             printk("cpu%d init failed (hwid %"PRIregister"): %d\n", i, hwid, rc);
             tmp_map[i] = MPIDR_INVALID;
+            node_map[i] = NUMA_NO_NODE;
         }
         else
+        {
             tmp_map[i] = hwid;
+            node_map[i] = nid;
+        }
     }
 
     if ( !bootcpu_valid )
@@ -246,6 +277,11 @@ static void __init dt_smp_init_cpus(void)
             continue;
         cpumask_set_cpu(i, &cpu_possible_map);
         cpu_logical_map(i) = tmp_map[i];
+
+        nid = node_map[i];
+        if ( nid >= MAX_NUMNODES )
+            nid = 0;
+        numa_set_node(i, nid);
     }
 }
 
-- 
2.25.1

[PATCH v5 06/17] xen/arm: Add boot and secondary CPU to NUMA system

[Henry Wang]

From: Wei Chen <wei.chen@arm.com>

In this patch, we make NUMA node online and add cpu to
its NUMA node. This will make NUMA-aware components
have NUMA affinity data to support their work.

To keep the mostly the same behavior of x86, we use
numa_detect_cpu_node to online node. The difference is that,
we have prepared cpu_to_node in dt_smp_init_cpus, so we don't
need to setup cpu_to_node in numa_detect_cpu_node.

Signed-off-by: Wei Chen <wei.chen@arm.com>
Signed-off-by: Henry Wang <Henry.Wang@arm.com>
---
v4 -> v5:
1. No change.
v3 -> v4:
1. No change.
v2 -> v3:
1. No change.
v1 -> v2:
1. Use unsigned int instead of int for cpu id.
2. Use static inline for stub to do type check.
---
 xen/arch/arm/include/asm/numa.h |  9 +++++++++
 xen/arch/arm/numa.c             | 10 ++++++++++
 xen/arch/arm/setup.c            |  5 +++++
 3 files changed, 24 insertions(+)

diff --git a/xen/arch/arm/include/asm/numa.h b/xen/arch/arm/include/asm/numa.h
index 97d4a67dea..b04ace26db 100644
--- a/xen/arch/arm/include/asm/numa.h
+++ b/xen/arch/arm/include/asm/numa.h
@@ -35,6 +35,7 @@ typedef u8 nodeid_t;
 extern bool numa_disabled(void);
 extern void numa_set_distance(nodeid_t from, nodeid_t to,
                               unsigned int distance);
+extern void numa_detect_cpu_node(unsigned int cpu);
 
 #else
 
@@ -72,6 +73,14 @@ static inline void numa_set_node(unsigned int cpu, nodeid_t node)
 {
 }
 
+static inline void numa_add_cpu(unsigned int cpu)
+{
+}
+
+static inline void numa_detect_cpu_node(unsigned int cpu)
+{
+}
+
 #endif
 
 #define arch_want_default_dmazone() (false)
diff --git a/xen/arch/arm/numa.c b/xen/arch/arm/numa.c
index e9b2ec93bc..b5a87531f7 100644
--- a/xen/arch/arm/numa.c
+++ b/xen/arch/arm/numa.c
@@ -76,6 +76,16 @@ void __init numa_set_distance(nodeid_t from, nodeid_t to,
     node_distance_map[from][to] = distance;
 }
 
+void numa_detect_cpu_node(unsigned int cpu)
+{
+    nodeid_t node = cpu_to_node[cpu];
+
+    if ( node == NUMA_NO_NODE )
+        node = 0;
+
+    node_set_online(node);
+}
+
 unsigned char __node_distance(nodeid_t from, nodeid_t to)
 {
     if ( from == to )
diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c
index 74b40e527f..ab9eb6fb80 100644
--- a/xen/arch/arm/setup.c
+++ b/xen/arch/arm/setup.c
@@ -1205,6 +1205,11 @@ void __init start_xen(unsigned long boot_phys_offset,
 
     for_each_present_cpu ( i )
     {
+        /* Detect and online node based on cpu_to_node[]. */
+        numa_detect_cpu_node(i);
+        /* Set up node_to_cpumask based on cpu_to_node[]. */
+        numa_add_cpu(i);
+
         if ( (num_online_cpus() < nr_cpu_ids) && !cpu_online(i) )
         {
             int ret = cpu_up(i);
-- 
2.25.1

[PATCH v5 07/17] xen/arm: introduce a helper to parse device tree processor node

[Henry Wang]

From: Wei Chen <wei.chen@arm.com>

Processor NUMA ID information is stored in device tree's processor
node as "numa-node-id". We need a new helper to parse this ID from
processor node. If we get this ID from processor node, this ID's
validity still need to be checked. Once we got a invalid NUMA ID
from any processor node, the device tree will be marked as NUMA
information invalid.

Since new helpers need to know the NUMA status, move the
enum dt_numa_status to the Arm NUMA header.

Signed-off-by: Wei Chen <wei.chen@arm.com>
Signed-off-by: Henry Wang <Henry.Wang@arm.com>
---
v4 -> v5:
1. Rename "numa_device_tree.c" to "numa-dt.c".
v3 -> v4:
1. No change.
v2 -> v3:
1. Move the enum dt_numa_status to the Arm NUMA header.
2. Update the year in copyright to 2023.
v1 -> v2:
1. Move numa_disabled from fdt_numa_processor_affinity_init
   to fdt_parse_numa_cpu_node.
2. Move invalid NUMA id check to fdt_parse_numa_cpu_node.
3. Return ENODATA for normal dtb without NUMA info.
4. Use NUMA status helpers instead of SRAT functions.
---
 xen/arch/arm/Makefile           |  1 +
 xen/arch/arm/include/asm/numa.h |  8 +++++
 xen/arch/arm/numa-dt.c          | 64 +++++++++++++++++++++++++++++++++
 xen/arch/arm/numa.c             |  8 +----
 4 files changed, 74 insertions(+), 7 deletions(-)
 create mode 100644 xen/arch/arm/numa-dt.c

diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile
index 814c472c4f..d4cf2f7752 100644
--- a/xen/arch/arm/Makefile
+++ b/xen/arch/arm/Makefile
@@ -39,6 +39,7 @@ obj-y += mem_access.o
 obj-y += mm.o
 obj-y += monitor.o
 obj-$(CONFIG_NUMA) += numa.o
+obj-$(CONFIG_DEVICE_TREE_NUMA) += numa-dt.o
 obj-y += p2m.o
 obj-y += percpu.o
 obj-y += platform.o
diff --git a/xen/arch/arm/include/asm/numa.h b/xen/arch/arm/include/asm/numa.h
index b04ace26db..2987158d16 100644
--- a/xen/arch/arm/include/asm/numa.h
+++ b/xen/arch/arm/include/asm/numa.h
@@ -22,6 +22,14 @@ typedef u8 nodeid_t;
  */
 #define NR_NODE_MEMBLKS NR_MEM_BANKS
 
+enum dt_numa_status {
+    DT_NUMA_DEFAULT,
+    DT_NUMA_ON,
+    DT_NUMA_OFF,
+};
+
+extern enum dt_numa_status device_tree_numa;
+
 /*
  * In ACPI spec, 0-9 are the reserved values for node distance,
  * 10 indicates local node distance, 20 indicates remote node
diff --git a/xen/arch/arm/numa-dt.c b/xen/arch/arm/numa-dt.c
new file mode 100644
index 0000000000..83601c83e7
--- /dev/null
+++ b/xen/arch/arm/numa-dt.c
@@ -0,0 +1,64 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Arm Architecture support layer for device tree NUMA.
+ *
+ * Copyright (C) 2023 Arm Ltd
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+#include <xen/init.h>
+#include <xen/nodemask.h>
+#include <xen/numa.h>
+#include <xen/libfdt/libfdt.h>
+#include <xen/device_tree.h>
+
+/* Callback for device tree processor affinity */
+static int __init fdt_numa_processor_affinity_init(nodeid_t node)
+{
+    numa_set_processor_nodes_parsed(node);
+    device_tree_numa = DT_NUMA_ON;
+
+    printk(KERN_INFO "DT: NUMA node %"PRIu8" processor parsed\n", node);
+
+    return 0;
+}
+
+/* Parse CPU NUMA node info */
+static int __init fdt_parse_numa_cpu_node(const void *fdt, int node)
+{
+    unsigned int nid;
+
+    if ( numa_disabled() )
+        return -EINVAL;
+
+    /*
+     * device_tree_get_u32 will return NUMA_NO_NODE when this CPU
+     * DT node doesn't have numa-node-id. This can help us to
+     * distinguish a bad DTB and a normal DTB without NUMA info.
+     */
+    nid = device_tree_get_u32(fdt, node, "numa-node-id", NUMA_NO_NODE);
+    if ( nid == NUMA_NO_NODE )
+    {
+        numa_fw_bad();
+        return -ENODATA;
+    }
+    else if ( nid >= MAX_NUMNODES )
+    {
+        printk(XENLOG_ERR "DT: CPU NUMA node id %u is invalid\n", nid);
+        numa_fw_bad();
+        return -EINVAL;
+    }
+
+    return fdt_numa_processor_affinity_init(nid);
+}
diff --git a/xen/arch/arm/numa.c b/xen/arch/arm/numa.c
index b5a87531f7..08e15ebbb0 100644
--- a/xen/arch/arm/numa.c
+++ b/xen/arch/arm/numa.c
@@ -20,13 +20,7 @@
 #include <xen/init.h>
 #include <xen/numa.h>
 
-enum dt_numa_status {
-    DT_NUMA_DEFAULT,
-    DT_NUMA_ON,
-    DT_NUMA_OFF,
-};
-
-static enum dt_numa_status __ro_after_init device_tree_numa = DT_NUMA_DEFAULT;
+enum dt_numa_status __ro_after_init device_tree_numa = DT_NUMA_DEFAULT;
 
 static unsigned char __ro_after_init
 node_distance_map[MAX_NUMNODES][MAX_NUMNODES] = {
-- 
2.25.1

[PATCH v5 08/17] xen/arm: introduce a helper to parse device tree memory node

[Henry Wang]

From: Wei Chen <wei.chen@arm.com>

Memory blocks' NUMA ID information is stored in device tree's
memory nodes as "numa-node-id". We need a new helper to parse
and verify this ID from memory nodes.

Signed-off-by: Wei Chen <wei.chen@arm.com>
Signed-off-by: Henry Wang <Henry.Wang@arm.com>
---
v4 -> v5:
1. Fix coding style: printk variable type and label indented.
v3 -> v4:
1. No change.
v2 -> v3:
1. No change.
v1 -> v2:
1. Move numa_disabled check to fdt_parse_numa_memory_node.
2. Use numa_bad to replace bad_srat.
3. Replace tabs by spaces.
4. Align parameters.
5. return ENODATA for a normal dtb without numa info.
6. Un-addressed comment:
   "Why not parse numa-node-id and call fdt_numa_memory_affinity_init
   from xen/arch/arm/bootfdt.c:device_tree_get_meminfo. Is it because
   device_tree_get_meminfo is called too early?"
   I checked the device_tree_get_meminfo code and I think the answer
   is similar as I reply in RFC. I prefer a unify numa initialization
   entry. Don't want to make numa parse code in different places.
7. Use node id as dummy PXM for numa_update_node_memblks.
---
 xen/arch/arm/numa-dt.c | 89 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 89 insertions(+)

diff --git a/xen/arch/arm/numa-dt.c b/xen/arch/arm/numa-dt.c
index 83601c83e7..cebc7e4300 100644
--- a/xen/arch/arm/numa-dt.c
+++ b/xen/arch/arm/numa-dt.c
@@ -34,6 +34,26 @@ static int __init fdt_numa_processor_affinity_init(nodeid_t node)
     return 0;
 }
 
+/* Callback for parsing of the memory regions affinity */
+static int __init fdt_numa_memory_affinity_init(nodeid_t node,
+                                                paddr_t start, paddr_t size)
+{
+    if ( !numa_memblks_available() )
+    {
+        dprintk(XENLOG_WARNING,
+                "Too many NUMA entries, try bigger NR_NODE_MEMBLKS\n");
+        return -EINVAL;
+    }
+
+    numa_fw_nid_name = "numa-node-id";
+    if ( !numa_update_node_memblks(node, node, start, size, false) )
+        return -EINVAL;
+
+    device_tree_numa = DT_NUMA_ON;
+
+    return 0;
+}
+
 /* Parse CPU NUMA node info */
 static int __init fdt_parse_numa_cpu_node(const void *fdt, int node)
 {
@@ -62,3 +82,72 @@ static int __init fdt_parse_numa_cpu_node(const void *fdt, int node)
 
     return fdt_numa_processor_affinity_init(nid);
 }
+
+/* Parse memory node NUMA info */
+static int __init fdt_parse_numa_memory_node(const void *fdt, int node,
+                                             const char *name,
+                                             unsigned int addr_cells,
+                                             unsigned int size_cells)
+{
+    unsigned int nid;
+    int ret = 0, len;
+    paddr_t addr, size;
+    const struct fdt_property *prop;
+    unsigned int idx, ranges;
+    const __be32 *addresses;
+
+    if ( numa_disabled() )
+        return -EINVAL;
+
+    /*
+     * device_tree_get_u32 will return NUMA_NO_NODE when this memory
+     * DT node doesn't have numa-node-id. This can help us to
+     * distinguish a bad DTB and a normal DTB without NUMA info.
+     */
+    nid = device_tree_get_u32(fdt, node, "numa-node-id", NUMA_NO_NODE);
+    if ( node == NUMA_NO_NODE )
+    {
+        numa_fw_bad();
+        return -ENODATA;
+    }
+    else if ( nid >= MAX_NUMNODES )
+    {
+        printk(XENLOG_WARNING "Node id %u exceeds maximum value\n", nid);
+        goto invalid_data;
+    }
+
+    prop = fdt_get_property(fdt, node, "reg", &len);
+    if ( !prop )
+    {
+        printk(XENLOG_WARNING
+               "fdt: node `%s': missing `reg' property\n", name);
+        goto invalid_data;
+    }
+
+    addresses = (const __be32 *)prop->data;
+    ranges = len / (sizeof(__be32)* (addr_cells + size_cells));
+    for ( idx = 0; idx < ranges; idx++ )
+    {
+        device_tree_get_reg(&addresses, addr_cells, size_cells, &addr, &size);
+        /* Skip zero size ranges */
+        if ( !size )
+            continue;
+
+        ret = fdt_numa_memory_affinity_init(nid, addr, size);
+        if ( ret )
+            goto invalid_data;
+    }
+
+    if ( idx == 0 )
+    {
+        printk(XENLOG_ERR
+               "bad property in memory node, idx=%u ret=%d\n", idx, ret);
+        goto invalid_data;
+    }
+
+    return 0;
+
+ invalid_data:
+    numa_fw_bad();
+    return -EINVAL;
+}
-- 
2.25.1

[PATCH v5 09/17] xen/arm: introduce a helper to parse device tree NUMA distance map

[Henry Wang]

From: Wei Chen <wei.chen@arm.com>

A NUMA aware device tree will provide a "distance-map" node to
describe distance between any two nodes. This patch introduce a
new helper to parse this distance map.

Note that, since the NUMA device tree binding does not explicitly
specify the range of valid node distance, hence rather than
rejecting node distance values >= 0xff, saturate the distance at
0xfe, while keeping 0xff for NUMA_NO_DISTANCE, so overall we can
keep things consistent with ACPI.

Signed-off-by: Wei Chen <wei.chen@arm.com>
Signed-off-by: Henry Wang <Henry.Wang@arm.com>
---
v4 -> v5:
1. Fix coding style (printk variable type and label indented) and
   in-code comment.
2. Check the from/to range to avoid the side-effect of the 8-bit
   truncation by numa_set_distance().
v3 -> v4:
1. The distance map default value is now NUMA_NO_DISTANCE, update
   the logic accordingly and add in-code comment as a note.
v2 -> v3:
1. No change.
v1 -> v2:
1. Get rid of useless braces.
2. Use new NUMA status helper.
3. Use PRIu32 to replace u in print messages.
4. Fix opposite = __node_distance(to, from).
5. disable dtb numa info table when we find an invalid data
   in dtb.
---
 xen/arch/arm/numa-dt.c | 116 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 116 insertions(+)

diff --git a/xen/arch/arm/numa-dt.c b/xen/arch/arm/numa-dt.c
index cebc7e4300..2fb6663e08 100644
--- a/xen/arch/arm/numa-dt.c
+++ b/xen/arch/arm/numa-dt.c
@@ -151,3 +151,119 @@ static int __init fdt_parse_numa_memory_node(const void *fdt, int node,
     numa_fw_bad();
     return -EINVAL;
 }
+
+/* Parse NUMA distance map v1 */
+static int __init fdt_parse_numa_distance_map_v1(const void *fdt, int node)
+{
+    const struct fdt_property *prop;
+    const __be32 *matrix;
+    unsigned int i, entry_count;
+    int len;
+
+    printk(XENLOG_INFO "NUMA: parsing numa-distance-map\n");
+
+    prop = fdt_get_property(fdt, node, "distance-matrix", &len);
+    if ( !prop )
+    {
+        printk(XENLOG_WARNING
+               "NUMA: No distance-matrix property in distance-map\n");
+        goto invalid_data;
+    }
+
+    if ( len % sizeof(__be32) != 0 )
+    {
+        printk(XENLOG_WARNING
+               "distance-matrix in node is not a multiple of u32\n");
+        goto invalid_data;
+    }
+
+    entry_count = len / sizeof(__be32);
+    if ( entry_count == 0 )
+    {
+        printk(XENLOG_WARNING "NUMA: Invalid distance-matrix\n");
+        goto invalid_data;
+    }
+
+    matrix = (const __be32 *)prop->data;
+    for ( i = 0; i + 2 < entry_count; i += 3 )
+    {
+        unsigned int from, to, distance, opposite;
+
+        from = dt_next_cell(1, &matrix);
+        to = dt_next_cell(1, &matrix);
+        distance = dt_next_cell(1, &matrix);
+
+        if ( from >= MAX_NUMNODES || to >= MAX_NUMNODES )
+        {
+            printk(XENLOG_WARNING "NUMA: invalid nodes: from=%u to=%u MAX=%u\n",
+                   from, to, MAX_NUMNODES);
+            goto invalid_data;
+        }
+
+        if ( (from == to && distance != NUMA_LOCAL_DISTANCE) ||
+             (from != to && distance <= NUMA_LOCAL_DISTANCE) )
+        {
+            printk(XENLOG_WARNING
+                   "NUMA: Invalid distance: NODE#%u->NODE#%u:%u\n",
+                   from, to, distance);
+            goto invalid_data;
+        }
+
+        printk(XENLOG_INFO "NUMA: distance: NODE#%u->NODE#%u:%u\n",
+               from, to, distance);
+
+        /* Get opposite way distance */
+        opposite = __node_distance(to, from);
+        /* The default value in node_distance_map is NUMA_NO_DISTANCE */
+        if ( opposite == NUMA_NO_DISTANCE )
+        {
+            /* Bi-directions are not set, set both */
+            numa_set_distance(from, to, distance);
+            numa_set_distance(to, from, distance);
+        }
+        else
+        {
+            /*
+             * Opposite way distance has been set to a different value.
+             * It may be a firmware device tree bug?
+             */
+            if ( opposite != distance )
+            {
+                /*
+                 * In device tree NUMA distance-matrix binding:
+                 * https://www.kernel.org/doc/Documentation/devicetree/bindings/numa.txt
+                 * There is a notes mentions:
+                 * "Each entry represents distance from first node to
+                 *  second node. The distances are equal in either
+                 *  direction."
+                 *
+                 * That means device tree doesn't permit this case.
+                 * But in ACPI spec, it cares to specifically permit this
+                 * case:
+                 * "Except for the relative distance from a System Locality
+                 *  to itself, each relative distance is stored twice in the
+                 *  matrix. This provides the capability to describe the
+                 *  scenario where the relative distances for the two
+                 *  directions between System Localities is different."
+                 *
+                 * That means a real machine allows such NUMA configuration.
+                 * So, place a WARNING here to notice system administrators,
+                 * is it the special case that they hijack the device tree
+                 * to support their rare machines?
+                 */
+                printk(XENLOG_WARNING
+                       "Un-matched bi-direction! NODE#%u->NODE#%u:%u, NODE#%u->NODE#%u:%u\n",
+                       from, to, distance, to, from, opposite);
+            }
+
+            /* Opposite way distance was set before, just set this way */
+            numa_set_distance(from, to, distance);
+        }
+    }
+
+    return 0;
+
+ invalid_data:
+    numa_fw_bad();
+    return -EINVAL;
+}
-- 
2.25.1

[PATCH v5 10/17] xen/arm: unified entry to parse all NUMA data from device tree

[Henry Wang]

From: Wei Chen <wei.chen@arm.com>

In this function, we scan the whole device tree to parse CPU node id,
memory node id and distance-map. Though early_scan_node will invoke
a handler to process memory nodes. If we want to parse memory node id
in that handler, we have to embed NUMA parse code in that handler.
But we still need to scan whole device tree to find CPU NUMA id and
distance-map. In this case, we include memory NUMA id parse in this
function too. Another benefit is that we have a unique entry for device
tree NUMA data parse.

Signed-off-by: Wei Chen <wei.chen@arm.com>
Signed-off-by: Henry Wang <Henry.Wang@arm.com>
---
v4 -> v5:
1. No change.
v3 -> v4:
1. No change.
v2 -> v3:
1. No change.
v1 -> v2:
1. Fix typos in commit message.
2. Fix code style and align parameters.
3. Use strncmp to replace memcmp.
---
 xen/arch/arm/include/asm/numa.h |  1 +
 xen/arch/arm/numa-dt.c          | 30 ++++++++++++++++++++++++++++++
 2 files changed, 31 insertions(+)

diff --git a/xen/arch/arm/include/asm/numa.h b/xen/arch/arm/include/asm/numa.h
index 2987158d16..15308f5a36 100644
--- a/xen/arch/arm/include/asm/numa.h
+++ b/xen/arch/arm/include/asm/numa.h
@@ -44,6 +44,7 @@ extern bool numa_disabled(void);
 extern void numa_set_distance(nodeid_t from, nodeid_t to,
                               unsigned int distance);
 extern void numa_detect_cpu_node(unsigned int cpu);
+extern int numa_device_tree_init(const void *fdt);
 
 #else
 
diff --git a/xen/arch/arm/numa-dt.c b/xen/arch/arm/numa-dt.c
index 2fb6663e08..8198a0da2e 100644
--- a/xen/arch/arm/numa-dt.c
+++ b/xen/arch/arm/numa-dt.c
@@ -267,3 +267,33 @@ static int __init fdt_parse_numa_distance_map_v1(const void *fdt, int node)
     numa_fw_bad();
     return -EINVAL;
 }
+
+static int __init fdt_scan_numa_nodes(const void *fdt, int node,
+                                      const char *uname, int depth,
+                                      unsigned int address_cells,
+                                      unsigned int size_cells, void *data)
+{
+    int len, ret = 0;
+    const void *prop;
+
+    prop = fdt_getprop(fdt, node, "device_type", &len);
+    if ( prop )
+    {
+        if ( strncmp(prop, "cpu", len) == 0 )
+            ret = fdt_parse_numa_cpu_node(fdt, node);
+        else if ( strncmp(prop, "memory", len) == 0 )
+            ret = fdt_parse_numa_memory_node(fdt, node, uname,
+                                address_cells, size_cells);
+    }
+    else if ( fdt_node_check_compatible(fdt, node,
+                                        "numa-distance-map-v1") == 0 )
+        ret = fdt_parse_numa_distance_map_v1(fdt, node);
+
+    return ret;
+}
+
+/* Initialize NUMA from device tree */
+int __init numa_device_tree_init(const void *fdt)
+{
+    return device_tree_for_each_node(fdt, 0, fdt_scan_numa_nodes, NULL);
+}
-- 
2.25.1

[PATCH v5 11/17] xen/arm: keep guest still be NUMA unware

[Henry Wang]

From: Wei Chen <wei.chen@arm.com>

The NUMA information provided in the host Device-Tree
are only for Xen. For dom0, we want to hide them as they
may be different (for now, dom0 is still not aware of NUMA)
The CPU and memory nodes are recreated from scratch for the
domain. So we already skip the "numa-node-id" property for
these two types of nodes.

However, some devices like PCIe may have "numa-node-id"
property too. We have to skip them as well.

Signed-off-by: Wei Chen <wei.chen@arm.com>
Signed-off-by: Henry Wang <Henry.Wang@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
---
v4 -> v5:
1. No change.
v3 -> v4:
1. No change.
v2 -> v3:
1. No change.
v1 -> v2:
1. Add Rb
---
 xen/arch/arm/domain_build.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
index 3f4558ade6..bf2aa3d56c 100644
--- a/xen/arch/arm/domain_build.c
+++ b/xen/arch/arm/domain_build.c
@@ -1185,6 +1185,10 @@ static int __init write_properties(struct domain *d, struct kernel_info *kinfo,
                 continue;
         }
 
+        /* Dom0 is currently NUMA unaware */
+        if ( dt_property_name_is_equal(prop, "numa-node-id") )
+            continue;
+
         res = fdt_property(kinfo->fdt, prop->name, prop_data, prop_len);
 
         if ( res )
@@ -2584,6 +2588,8 @@ static int __init handle_node(struct domain *d, struct kernel_info *kinfo,
         DT_MATCH_TYPE("memory"),
         /* The memory mapped timer is not supported by Xen. */
         DT_MATCH_COMPATIBLE("arm,armv7-timer-mem"),
+        /* Numa info doesn't need to be exposed to Domain-0 */
+        DT_MATCH_COMPATIBLE("numa-distance-map-v1"),
         { /* sentinel */ },
     };
     static const struct dt_device_match timer_matches[] __initconst =
-- 
2.25.1

[PATCH v5 12/17] xen/arm: enable device tree based NUMA in system init

[Henry Wang]

From: Wei Chen <wei.chen@arm.com>

In this patch, we can start to create NUMA system that is
based on device tree.

Signed-off-by: Wei Chen <wei.chen@arm.com>
Signed-off-by: Henry Wang <Henry.Wang@arm.com>
---
v4 -> v5:
1. Fix coding style: label indented by 1 space.
v3 -> v4:
1. No change.
v2 -> v3:
1. No change.
v1 -> v2:
1. replace ~0 by INVALID_PADDR.
2. only print error messages for invalid dtb data.
3. remove unnecessary return.
4. remove the parameter of numa_init.
---
 xen/arch/arm/include/asm/numa.h |  5 +++
 xen/arch/arm/numa.c             | 57 +++++++++++++++++++++++++++++++++
 xen/arch/arm/setup.c            |  7 ++++
 3 files changed, 69 insertions(+)

diff --git a/xen/arch/arm/include/asm/numa.h b/xen/arch/arm/include/asm/numa.h
index 15308f5a36..55ac4665db 100644
--- a/xen/arch/arm/include/asm/numa.h
+++ b/xen/arch/arm/include/asm/numa.h
@@ -45,6 +45,7 @@ extern void numa_set_distance(nodeid_t from, nodeid_t to,
                               unsigned int distance);
 extern void numa_detect_cpu_node(unsigned int cpu);
 extern int numa_device_tree_init(const void *fdt);
+extern void numa_init(void);
 
 #else
 
@@ -90,6 +91,10 @@ static inline void numa_detect_cpu_node(unsigned int cpu)
 {
 }
 
+static inline void numa_init(void)
+{
+}
+
 #endif
 
 #define arch_want_default_dmazone() (false)
diff --git a/xen/arch/arm/numa.c b/xen/arch/arm/numa.c
index 08e15ebbb0..13a167fc4f 100644
--- a/xen/arch/arm/numa.c
+++ b/xen/arch/arm/numa.c
@@ -18,7 +18,11 @@
  *
  */
 #include <xen/init.h>
+#include <xen/device_tree.h>
+#include <xen/nodemask.h>
 #include <xen/numa.h>
+#include <xen/pfn.h>
+#include <xen/acpi.h>
 
 enum dt_numa_status __ro_after_init device_tree_numa = DT_NUMA_DEFAULT;
 
@@ -104,6 +108,59 @@ unsigned char __node_distance(nodeid_t from, nodeid_t to)
     return node_distance_map[from][to];
 }
 
+void __init numa_init(void)
+{
+    unsigned int idx;
+    paddr_t ram_start = INVALID_PADDR;
+    paddr_t ram_size = 0;
+    paddr_t ram_end = 0;
+
+    /* NUMA has been turned off through Xen parameters */
+    if ( numa_off )
+        goto mem_init;
+
+    /* Initialize NUMA from device tree when system is not ACPI booted */
+    if ( acpi_disabled )
+    {
+        int ret = numa_device_tree_init(device_tree_flattened);
+        if ( ret )
+        {
+            numa_off = true;
+            if ( ret == -EINVAL )
+                printk(XENLOG_WARNING
+                       "Init NUMA from device tree failed, ret=%d\n", ret);
+        }
+    }
+    else
+    {
+        /* We don't support NUMA for ACPI boot currently */
+        printk(XENLOG_WARNING
+               "ACPI NUMA has not been supported yet, NUMA off!\n");
+        numa_off = true;
+    }
+
+ mem_init:
+    /*
+     * Find the minimal and maximum address of RAM, NUMA will
+     * build a memory to node mapping table for the whole range.
+     */
+    ram_start = bootinfo.mem.bank[0].start;
+    ram_size  = bootinfo.mem.bank[0].size;
+    ram_end   = ram_start + ram_size;
+    for ( idx = 1 ; idx < bootinfo.mem.nr_banks; idx++ )
+    {
+        paddr_t bank_start = bootinfo.mem.bank[idx].start;
+        paddr_t bank_size = bootinfo.mem.bank[idx].size;
+        paddr_t bank_end = bank_start + bank_size;
+
+        ram_size  = ram_size + bank_size;
+        ram_start = min(ram_start, bank_start);
+        ram_end   = max(ram_end, bank_end);
+    }
+
+    numa_initmem_init(PFN_UP(ram_start), PFN_DOWN(ram_end));
+}
+
 int __init arch_get_ram_range(unsigned int idx, paddr_t *start, paddr_t *end)
 {
     if ( idx >= bootinfo.mem.nr_banks )
diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c
index ab9eb6fb80..bfcb0c7b6b 100644
--- a/xen/arch/arm/setup.c
+++ b/xen/arch/arm/setup.c
@@ -1121,6 +1121,13 @@ void __init start_xen(unsigned long boot_phys_offset,
     /* Parse the ACPI tables for possible boot-time configuration */
     acpi_boot_table_init();
 
+    /*
+     * Try to initialize NUMA system, if failed, the system will
+     * fallback to uniform system which means system has only 1
+     * NUMA node.
+     */
+    numa_init();
+
     end_boot_allocator();
 
     /*
-- 
2.25.1

[PATCH v5 13/17] xen/arm: implement numa_node_to_arch_nid for device tree NUMA

[Henry Wang]

From: Wei Chen <wei.chen@arm.com>

Device tree based NUMA doesn't have the proximity domain like
ACPI. So we can return node id directly as arch nid.

Signed-off-by: Wei Chen <wei.chen@arm.com>
Signed-off-by: Henry Wang <Henry.Wang@arm.com>
---
v4 -> v5:
1. No change.
v3 -> v4:
1. No change.
v2 -> v3:
1. No change.
v1 -> v2:
1. Use numa_node_to_arch_nid instead of dummy node_to_pxm.
---
 xen/arch/arm/include/asm/numa.h | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/xen/arch/arm/include/asm/numa.h b/xen/arch/arm/include/asm/numa.h
index 55ac4665db..71b95a9a62 100644
--- a/xen/arch/arm/include/asm/numa.h
+++ b/xen/arch/arm/include/asm/numa.h
@@ -47,6 +47,15 @@ extern void numa_detect_cpu_node(unsigned int cpu);
 extern int numa_device_tree_init(const void *fdt);
 extern void numa_init(void);
 
+/*
+ * Device tree NUMA doesn't have architecural node id.
+ * So we can just return node id as arch nid.
+ */
+static inline unsigned int numa_node_to_arch_nid(nodeid_t n)
+{
+    return n;
+}
+
 #else
 
 /* Fake one node for now. See also node_online_map. */
-- 
2.25.1

[PATCH v5 14/17] xen/arm: use CONFIG_NUMA to gate node_online_map in smpboot

[Henry Wang]

From: Wei Chen <wei.chen@arm.com>

node_online_map in smpboot is still needed for Arm when NUMA is
turned off by Kconfig.

Signed-off-by: Wei Chen <wei.chen@arm.com>
Signed-off-by: Henry Wang <Henry.Wang@arm.com>
---
v4 -> v5:
1. No change.
v3 -> v4:
1. No change.
v2 -> v3:
1. No change.
v1 -> v2:
1. No change.
---
 xen/arch/arm/smpboot.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/xen/arch/arm/smpboot.c b/xen/arch/arm/smpboot.c
index 7506085540..eedbb57291 100644
--- a/xen/arch/arm/smpboot.c
+++ b/xen/arch/arm/smpboot.c
@@ -41,8 +41,10 @@ integer_param("maxcpus", max_cpus);
 /* CPU logical map: map xen cpuid to an MPIDR */
 register_t __cpu_logical_map[NR_CPUS] = { [0 ... NR_CPUS-1] = MPIDR_INVALID };
 
+#ifndef CONFIG_NUMA
 /* Fake one node for now. See also asm/numa.h */
 nodemask_t __read_mostly node_online_map = { { [0] = 1UL } };
+#endif
 
 /* Xen stack for bringing up the first CPU. */
 static unsigned char __initdata cpu0_boot_stack[STACK_SIZE]
-- 
2.25.1

[PATCH v5 15/17] xen/arm: Set correct per-cpu cpu_core_mask

[Henry Wang]

In the common sysctl command XEN_SYSCTL_physinfo, the cores_per_socket
is calculated based on the cpu_core_mask of CPU0. Currently on Arm
this is a fixed value 1 (can be checked via xl info), which is not
correct. This is because during the Arm cpu online process,
set_cpu_sibling_map() only sets the per-cpu cpu_core_mask for itself.

cores_per_socket refers to the number of cores that belong to the same
socket (NUMA node). Therefore, this commit introduces a helper function
numa_set_cpu_core_mask(cpu), which sets the per-cpu cpu_core_mask to
the cpus in the same NUMA node as cpu. Calling this function at the
boot time can ensure the correct cpu_core_mask, leading to the correct
cores_per_socket to be returned by XEN_SYSCTL_physinfo.

Signed-off-by: Henry Wang <Henry.Wang@arm.com>
---
v4 -> v5:
1. No change.
v3 -> v4:
1. No change.
v2 -> v3:
1. No change.
v1 -> v2:
1. New patch
---
 xen/arch/arm/include/asm/numa.h |  7 +++++++
 xen/arch/arm/numa.c             | 11 +++++++++++
 xen/arch/arm/setup.c            |  5 +++++
 3 files changed, 23 insertions(+)

diff --git a/xen/arch/arm/include/asm/numa.h b/xen/arch/arm/include/asm/numa.h
index 71b95a9a62..d4c89909d0 100644
--- a/xen/arch/arm/include/asm/numa.h
+++ b/xen/arch/arm/include/asm/numa.h
@@ -46,6 +46,7 @@ extern void numa_set_distance(nodeid_t from, nodeid_t to,
 extern void numa_detect_cpu_node(unsigned int cpu);
 extern int numa_device_tree_init(const void *fdt);
 extern void numa_init(void);
+extern void numa_set_cpu_core_mask(int cpu);
 
 /*
  * Device tree NUMA doesn't have architecural node id.
@@ -62,6 +63,12 @@ static inline unsigned int numa_node_to_arch_nid(nodeid_t n)
 #define cpu_to_node(cpu) 0
 #define node_to_cpumask(node)   (cpu_online_map)
 
+static inline void numa_set_cpu_core_mask(int cpu)
+{
+    cpumask_or(per_cpu(cpu_core_mask, cpu),
+               per_cpu(cpu_core_mask, cpu), &cpu_possible_map);
+}
+
 /*
  * TODO: make first_valid_mfn static when NUMA is supported on Arm, this
  * is required because the dummy helpers are using it.
diff --git a/xen/arch/arm/numa.c b/xen/arch/arm/numa.c
index 13a167fc4f..1ac2df37fc 100644
--- a/xen/arch/arm/numa.c
+++ b/xen/arch/arm/numa.c
@@ -52,6 +52,17 @@ int __init arch_numa_setup(const char *opt)
     return -EINVAL;
 }
 
+void numa_set_cpu_core_mask(int cpu)
+{
+    nodeid_t node = cpu_to_node[cpu];
+
+    if ( node == NUMA_NO_NODE )
+        node = 0;
+
+    cpumask_or(per_cpu(cpu_core_mask, cpu),
+               per_cpu(cpu_core_mask, cpu), &node_to_cpumask(node));
+}
+
 void __init numa_set_distance(nodeid_t from, nodeid_t to,
                               unsigned int distance)
 {
diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c
index bfcb0c7b6b..9b586605a6 100644
--- a/xen/arch/arm/setup.c
+++ b/xen/arch/arm/setup.c
@@ -1226,6 +1226,11 @@ void __init start_xen(unsigned long boot_phys_offset,
     }
 
     printk("Brought up %ld CPUs\n", (long)num_online_cpus());
+
+    /* Set per-cpu cpu_core_mask to cpus that belongs to the same NUMA node. */
+    for_each_online_cpu ( i )
+        numa_set_cpu_core_mask(i);
+
     /* TODO: smp_cpus_done(); */
 
     /* This should be done in a vpmu driver but we do not have one yet. */
-- 
2.25.1

[PATCH v5 16/17] xen/arm: Provide Kconfig options for Arm to enable NUMA

[Henry Wang]

From: Wei Chen <wei.chen@arm.com>

Arm platforms support both ACPI and device tree. We don't
want users to select device tree NUMA or ACPI NUMA manually.
We hope users can just enable NUMA for Arm, and device tree
NUMA and ACPI NUMA can be selected depends on device tree
feature and ACPI feature status automatically. In this case,
these two kinds of NUMA support code can be co-exist in one
Xen binary. Xen can check feature flags to decide using
device tree or ACPI as NUMA based firmware.

So in this patch, we introduce a generic option:
CONFIG_ARM_NUMA for users to enable NUMA for Arm.
And one CONFIG_DEVICE_TREE_NUMA option for ARM_NUMA
to select when HAS_DEVICE_TREE option is enabled.
Once when ACPI NUMA for Arm is supported, ACPI_NUMA
can be selected here too.

Signed-off-by: Wei Chen <wei.chen@arm.com>
Signed-off-by: Henry Wang <Henry.Wang@arm.com>
---
v4 -> v5:
1. No change.
v3 -> v4:
1. No change.
v2 -> v3:
1. No change.
v1 -> v2:
1. Remove the condition of selecting DEVICE_TREE_NUMA.
---
 xen/arch/arm/Kconfig | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig
index 239d3aed3c..e751ad50d1 100644
--- a/xen/arch/arm/Kconfig
+++ b/xen/arch/arm/Kconfig
@@ -39,6 +39,17 @@ config ACPI
 config ARM_EFI
 	bool
 
+config ARM_NUMA
+	bool "Arm NUMA (Non-Uniform Memory Access) Support (UNSUPPORTED)" if UNSUPPORTED
+	depends on HAS_DEVICE_TREE
+	select DEVICE_TREE_NUMA
+	help
+	  Enable Non-Uniform Memory Access (NUMA) for Arm architecutres
+
+config DEVICE_TREE_NUMA
+	bool
+	select NUMA
+
 config GICV3
 	bool "GICv3 driver"
 	depends on !NEW_VGIC
-- 
2.25.1

[PATCH v5 17/17] docs: update numa command line to support Arm

[Henry Wang]

From: Wei Chen <wei.chen@arm.com>

Current numa command in documentation is x86 only. Remove
x86 from numa command's arch limitation in this patch.

Signed-off-by: Wei Chen <wei.chen@arm.com>
Signed-off-by: Henry Wang <Henry.Wang@arm.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
---
v4 -> v5:
1. No change.
v3 -> v4:
1. No change.
v2 -> v3:
1. Add the Acked-by tag from Jan.
v1 -> v2:
1. Update Arm NUMA status in SUPPORT.md to "Tech Preview".
---
 SUPPORT.md                        | 1 +
 docs/misc/xen-command-line.pandoc | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/SUPPORT.md b/SUPPORT.md
index 6dbed9d5d0..8ab8b94afe 100644
--- a/SUPPORT.md
+++ b/SUPPORT.md
@@ -411,6 +411,7 @@ on embedded platforms and the x86 PV shim.
 Enables NUMA aware scheduling in Xen
 
     Status, x86: Supported
+    Status, Arm: Tech Preview
 
 ## Scalability
 
diff --git a/docs/misc/xen-command-line.pandoc b/docs/misc/xen-command-line.pandoc
index e0b89b7d33..2fea22dd70 100644
--- a/docs/misc/xen-command-line.pandoc
+++ b/docs/misc/xen-command-line.pandoc
@@ -1890,7 +1890,7 @@ i.e. a limit on the number of guests it is possible to start each having
 assigned a device sharing a common interrupt line.  Accepts values between
 1 and 255.
 
-### numa (x86)
+### numa
 > `= on | off | fake=<integer> | noacpi`
 
 > Default: `on`
-- 
2.25.1