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From:   David Hildenbrand <david@redhat.com>
To:     linux-kernel@vger.kernel.org
Cc:     linux-mm@kvack.org, virtio-dev@lists.oasis-open.org,
        virtualization@lists.linux-foundation.org, kvm@vger.kernel.org,
        Michal Hocko <mhocko@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        "Michael S . Tsirkin" <mst@redhat.com>,
        David Hildenbrand <david@redhat.com>,
        Michal Hocko <mhocko@suse.com>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Pankaj Gupta <pankaj.gupta.linux@gmail.com>,
        Jason Wang <jasowang@redhat.com>,
        Oscar Salvador <osalvador@suse.de>,
        Igor Mammedov <imammedo@redhat.com>,
        Dave Young <dyoung@redhat.com>,
        Dan Williams <dan.j.williams@intel.com>,
        Pavel Tatashin <pasha.tatashin@soleen.com>,
        Stefan Hajnoczi <stefanha@redhat.com>,
        Vlastimil Babka <vbabka@suse.cz>, Len Brown <lenb@kernel.org>,
        linux-acpi@vger.kernel.org
Subject: [PATCH v3 02/15] virtio-mem: Allow to specify an ACPI PXM as nid
Date:   Thu,  7 May 2020 12:31:06 +0200
Message-Id: <20200507103119.11219-3-david@redhat.com>
In-Reply-To: <20200507103119.11219-1-david@redhat.com>
References: <20200507103119.11219-1-david@redhat.com>
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We want to allow to specify (similar as for a DIMM), to which node a
virtio-mem device (and, therefore, its memory) belongs. Add a new
virtio-mem feature flag and export pxm_to_node, so it can be used in kern=
el
module context.

Acked-by: Michal Hocko <mhocko@suse.com> # for the export
Acked-by: "Rafael J. Wysocki" <rafael@kernel.org> # for the export
Acked-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Tested-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Len Brown <lenb@kernel.org>
Cc: linux-acpi@vger.kernel.org
Signed-off-by: David Hildenbrand <david@redhat.com>
---
 drivers/acpi/numa/srat.c        |  1 +
 drivers/virtio/virtio_mem.c     | 39 +++++++++++++++++++++++++++++++--
 include/uapi/linux/virtio_mem.h | 10 ++++++++-
 3 files changed, 47 insertions(+), 3 deletions(-)

diff --git a/drivers/acpi/numa/srat.c b/drivers/acpi/numa/srat.c
index 47b4969d9b93..5be5a977da1b 100644
--- a/drivers/acpi/numa/srat.c
+++ b/drivers/acpi/numa/srat.c
@@ -35,6 +35,7 @@ int pxm_to_node(int pxm)
 		return NUMA_NO_NODE;
 	return pxm_to_node_map[pxm];
 }
+EXPORT_SYMBOL(pxm_to_node);
=20
 int node_to_pxm(int node)
 {
diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c
index 5d1dcaa6fc42..270ddeaec059 100644
--- a/drivers/virtio/virtio_mem.c
+++ b/drivers/virtio/virtio_mem.c
@@ -21,6 +21,8 @@
 #include <linux/bitmap.h>
 #include <linux/lockdep.h>
=20
+#include <acpi/acpi_numa.h>
+
 enum virtio_mem_mb_state {
 	/* Unplugged, not added to Linux. Can be reused later. */
 	VIRTIO_MEM_MB_STATE_UNUSED =3D 0,
@@ -72,6 +74,8 @@ struct virtio_mem {
=20
 	/* The device block size (for communicating with the device). */
 	uint32_t device_block_size;
+	/* The translated node id. NUMA_NO_NODE in case not specified. */
+	int nid;
 	/* Physical start address of the memory region. */
 	uint64_t addr;
 	/* Maximum region size in bytes. */
@@ -389,7 +393,10 @@ static int virtio_mem_sb_bitmap_prepare_next_mb(stru=
ct virtio_mem *vm)
 static int virtio_mem_mb_add(struct virtio_mem *vm, unsigned long mb_id)
 {
 	const uint64_t addr =3D virtio_mem_mb_id_to_phys(mb_id);
-	int nid =3D memory_add_physaddr_to_nid(addr);
+	int nid =3D vm->nid;
+
+	if (nid =3D=3D NUMA_NO_NODE)
+		nid =3D memory_add_physaddr_to_nid(addr);
=20
 	dev_dbg(&vm->vdev->dev, "adding memory block: %lu\n", mb_id);
 	return add_memory(nid, addr, memory_block_size_bytes());
@@ -407,7 +414,10 @@ static int virtio_mem_mb_add(struct virtio_mem *vm, =
unsigned long mb_id)
 static int virtio_mem_mb_remove(struct virtio_mem *vm, unsigned long mb_=
id)
 {
 	const uint64_t addr =3D virtio_mem_mb_id_to_phys(mb_id);
-	int nid =3D memory_add_physaddr_to_nid(addr);
+	int nid =3D vm->nid;
+
+	if (nid =3D=3D NUMA_NO_NODE)
+		nid =3D memory_add_physaddr_to_nid(addr);
=20
 	dev_dbg(&vm->vdev->dev, "removing memory block: %lu\n", mb_id);
 	return remove_memory(nid, addr, memory_block_size_bytes());
@@ -426,6 +436,17 @@ static void virtio_mem_retry(struct virtio_mem *vm)
 	spin_unlock_irqrestore(&vm->removal_lock, flags);
 }
=20
+static int virtio_mem_translate_node_id(struct virtio_mem *vm, uint16_t =
node_id)
+{
+	int node =3D NUMA_NO_NODE;
+
+#if defined(CONFIG_ACPI_NUMA)
+	if (virtio_has_feature(vm->vdev, VIRTIO_MEM_F_ACPI_PXM))
+		node =3D pxm_to_node(node_id);
+#endif
+	return node;
+}
+
 /*
  * Test if a virtio-mem device overlaps with the given range. Can be cal=
led
  * from (notifier) callbacks lockless.
@@ -1267,6 +1288,7 @@ static bool virtio_mem_any_memory_present(unsigned =
long start,
 static int virtio_mem_init(struct virtio_mem *vm)
 {
 	const uint64_t phys_limit =3D 1UL << MAX_PHYSMEM_BITS;
+	uint16_t node_id;
=20
 	if (!vm->vdev->config->get) {
 		dev_err(&vm->vdev->dev, "config access disabled\n");
@@ -1287,6 +1309,9 @@ static int virtio_mem_init(struct virtio_mem *vm)
 		     &vm->plugged_size);
 	virtio_cread(vm->vdev, struct virtio_mem_config, block_size,
 		     &vm->device_block_size);
+	virtio_cread(vm->vdev, struct virtio_mem_config, node_id,
+		     &node_id);
+	vm->nid =3D virtio_mem_translate_node_id(vm, node_id);
 	virtio_cread(vm->vdev, struct virtio_mem_config, addr, &vm->addr);
 	virtio_cread(vm->vdev, struct virtio_mem_config, region_size,
 		     &vm->region_size);
@@ -1365,6 +1390,8 @@ static int virtio_mem_init(struct virtio_mem *vm)
 		 memory_block_size_bytes());
 	dev_info(&vm->vdev->dev, "subblock size: 0x%x",
 		 vm->subblock_size);
+	if (vm->nid !=3D NUMA_NO_NODE)
+		dev_info(&vm->vdev->dev, "nid: %d", vm->nid);
=20
 	return 0;
 }
@@ -1508,12 +1535,20 @@ static int virtio_mem_restore(struct virtio_devic=
e *vdev)
 }
 #endif
=20
+static unsigned int virtio_mem_features[] =3D {
+#if defined(CONFIG_NUMA) && defined(CONFIG_ACPI_NUMA)
+	VIRTIO_MEM_F_ACPI_PXM,
+#endif
+};
+
 static struct virtio_device_id virtio_mem_id_table[] =3D {
 	{ VIRTIO_ID_MEM, VIRTIO_DEV_ANY_ID },
 	{ 0 },
 };
=20
 static struct virtio_driver virtio_mem_driver =3D {
+	.feature_table =3D virtio_mem_features,
+	.feature_table_size =3D ARRAY_SIZE(virtio_mem_features),
 	.driver.name =3D KBUILD_MODNAME,
 	.driver.owner =3D THIS_MODULE,
 	.id_table =3D virtio_mem_id_table,
diff --git a/include/uapi/linux/virtio_mem.h b/include/uapi/linux/virtio_=
mem.h
index 1bfade78bdfd..e0a9dc7397c3 100644
--- a/include/uapi/linux/virtio_mem.h
+++ b/include/uapi/linux/virtio_mem.h
@@ -83,6 +83,12 @@
  * device is busy.
  */
=20
+/* --- virtio-mem: feature bits --- */
+
+/* node_id is an ACPI PXM and is valid */
+#define VIRTIO_MEM_F_ACPI_PXM		0
+
+
 /* --- virtio-mem: guest -> host requests --- */
=20
 /* request to plug memory blocks */
@@ -177,7 +183,9 @@ struct virtio_mem_resp {
 struct virtio_mem_config {
 	/* Block size and alignment. Cannot change. */
 	__u32 block_size;
-	__u32 padding;
+	/* Valid with VIRTIO_MEM_F_ACPI_PXM. Cannot change. */
+	__u16 node_id;
+	__u16 padding;
 	/* Start address of the memory region. Cannot change. */
 	__u64 addr;
 	/* Region size (maximum). Cannot change. */
--=20
2.25.3