Re: [PATCH 10/13] vfio/mdev: consolidate all the name sysfs into the core code

Kirti Wankhede <kwankhede@xxxxxxxxxx> · Thu, 16 Jun 2022 02:01:23 +0530

On 6/14/2022 10:24 AM, Christoph Hellwig wrote:
Every driver just emits a static string, simply add a field to the
mdev_type for the driver to fill out or fall back to the sysfs name and
provide a standard sysfs show function.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>

Reviewed-by: Kirti Wankhede <kwankhede@xxxxxxxxxx>

---
  .../driver-api/vfio-mediated-device.rst       |  2 +-
  drivers/gpu/drm/i915/gvt/kvmgt.c              |  8 -------
  drivers/s390/cio/vfio_ccw_ops.c               |  9 +-------
  drivers/s390/crypto/vfio_ap_ops.c             |  9 --------
  drivers/vfio/mdev/mdev_sysfs.c                | 11 ++++++++++
  include/linux/mdev.h                          |  1 +
  samples/vfio-mdev/mbochs.c                    | 20 ++++--------------
  samples/vfio-mdev/mdpy.c                      | 21 +++++--------------
  samples/vfio-mdev/mtty.c                      | 18 ++++------------
  9 files changed, 27 insertions(+), 72 deletions(-)

diff --git a/Documentation/driver-api/vfio-mediated-device.rst b/Documentation/driver-api/vfio-mediated-device.rst
index e9913bfb4393b..87d207744db79 100644
--- a/Documentation/driver-api/vfio-mediated-device.rst
+++ b/Documentation/driver-api/vfio-mediated-device.rst
@@ -219,7 +219,7 @@ Directories and files under the sysfs for Each Physical Device
  
  * name
  
-  This attribute should show human readable name. This is optional attribute.
+  This attribute shows a human readable name.
  
  * description
  
diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c
index 44a418d897377..191e64ef70acf 100644
--- a/drivers/gpu/drm/i915/gvt/kvmgt.c
+++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
@@ -138,20 +138,12 @@ static ssize_t description_show(struct mdev_type *mtype,
  		       type->weight);
  }
  
-static ssize_t name_show(struct mdev_type *mtype,
-			 struct mdev_type_attribute *attr, char *buf)
-{
-	return sprintf(buf, "%s\n", mtype->sysfs_name);
-}
-
  static MDEV_TYPE_ATTR_RO(available_instances);
  static MDEV_TYPE_ATTR_RO(description);
-static MDEV_TYPE_ATTR_RO(name);
  
  static const struct attribute *gvt_type_attrs[] = {
  	&mdev_type_attr_available_instances.attr,
  	&mdev_type_attr_description.attr,
-	&mdev_type_attr_name.attr,
  	NULL,
  };
  
diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c
index 730d87a96a305..35389f4b67dc5 100644
--- a/drivers/s390/cio/vfio_ccw_ops.c
+++ b/drivers/s390/cio/vfio_ccw_ops.c
@@ -70,13 +70,6 @@ static int vfio_ccw_mdev_notifier(struct notifier_block *nb,
  	return NOTIFY_DONE;
  }
  
-static ssize_t name_show(struct mdev_type *mtype,
-			 struct mdev_type_attribute *attr, char *buf)
-{
-	return sprintf(buf, "I/O subchannel (Non-QDIO)\n");
-}
-static MDEV_TYPE_ATTR_RO(name);
-
  static ssize_t available_instances_show(struct mdev_type *mtype,
  					struct mdev_type_attribute *attr,
  					char *buf)
@@ -88,7 +81,6 @@ static ssize_t available_instances_show(struct mdev_type *mtype,
  static MDEV_TYPE_ATTR_RO(available_instances);
  
  static const struct attribute *mdev_types_attrs[] = {
-	&mdev_type_attr_name.attr,
  	&mdev_type_attr_available_instances.attr,
  	NULL,
  };
@@ -642,6 +634,7 @@ struct mdev_driver vfio_ccw_mdev_driver = {
  int vfio_ccw_mdev_reg(struct subchannel *sch)
  {
  	strcat(sch->mdev_type.sysfs_name, "io");
+	strcat(sch->mdev_type.pretty_name, "I/O subchannel (Non-QDIO)");
  	sch->mdev_types[0] = &sch->mdev_type;
  	return mdev_register_parent(&sch->parent, &sch->dev,
  				    &vfio_ccw_mdev_driver, sch->mdev_types,
diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index da21fd60877fb..d6b2e819a615e 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -511,14 +511,6 @@ static void vfio_ap_mdev_remove(struct mdev_device *mdev)
  	atomic_inc(&matrix_dev->available_instances);
  }
  
-static ssize_t name_show(struct mdev_type *mtype,
-			 struct mdev_type_attribute *attr, char *buf)
-{
-	return sprintf(buf, "%s\n", VFIO_AP_MDEV_NAME_HWVIRT);
-}
-
-static MDEV_TYPE_ATTR_RO(name);
-
  static ssize_t available_instances_show(struct mdev_type *mtype,
  					struct mdev_type_attribute *attr,
  					char *buf)
@@ -530,7 +522,6 @@ static ssize_t available_instances_show(struct mdev_type *mtype,
  static MDEV_TYPE_ATTR_RO(available_instances);
  
  static const struct attribute *vfio_ap_mdev_type_attrs[] = {
-	&mdev_type_attr_name.attr,
  	&mdev_type_attr_available_instances.attr,
  	NULL,
  };
diff --git a/drivers/vfio/mdev/mdev_sysfs.c b/drivers/vfio/mdev/mdev_sysfs.c
index 20763f1aa9f5a..8384e2992c706 100644
--- a/drivers/vfio/mdev/mdev_sysfs.c
+++ b/drivers/vfio/mdev/mdev_sysfs.c
@@ -81,9 +81,20 @@ static ssize_t device_api_show(struct mdev_type *mtype,
  }
  static MDEV_TYPE_ATTR_RO(device_api);
  
+static ssize_t name_show(struct mdev_type *mtype,
+			 struct mdev_type_attribute *attr, char *buf)
+{
+	if (!mtype->pretty_name[0])
+		return sprintf(buf, "%s\n", mtype->sysfs_name);
+	return sprintf(buf, "%s\n", mtype->pretty_name);
+}
+
+static MDEV_TYPE_ATTR_RO(name);
+
  static struct attribute *mdev_types_core_attrs[] = {
  	&mdev_type_attr_create.attr,
  	&mdev_type_attr_device_api.attr,
+	&mdev_type_attr_name.attr,
  	NULL,
  };
  
diff --git a/include/linux/mdev.h b/include/linux/mdev.h
index 81e11e18b3e41..64ca2ba806ed3 100644
--- a/include/linux/mdev.h
+++ b/include/linux/mdev.h
@@ -26,6 +26,7 @@ struct mdev_device {
  struct mdev_type {
  	/* set by the driver before calling mdev_register parent: */
  	char sysfs_name[32];
+	char pretty_name[32]; /* optional */
  
  	/* set by the core, can be used drivers */
  	struct mdev_parent *parent;
diff --git a/samples/vfio-mdev/mbochs.c b/samples/vfio-mdev/mbochs.c
index 199846f01de92..c8271168a96ad 100644
--- a/samples/vfio-mdev/mbochs.c
+++ b/samples/vfio-mdev/mbochs.c
@@ -101,26 +101,25 @@ MODULE_PARM_DESC(mem, "megabytes available to " MBOCHS_NAME " devices");
  
  static struct mbochs_type {
  	struct mdev_type type;
-	const char *name;
  	u32 mbytes;
  	u32 max_x;
  	u32 max_y;
  } mbochs_types[] = {
  	{
  		.type.sysfs_name	= MBOCHS_TYPE_1,
-		.name	= MBOCHS_CLASS_NAME "-" MBOCHS_TYPE_1,
+		.type.pretty_name	= MBOCHS_CLASS_NAME "-" MBOCHS_TYPE_1,
  		.mbytes = 4,
  		.max_x  = 800,
  		.max_y  = 600,
  	}, {
  		.type.sysfs_name	= MBOCHS_TYPE_2,
-		.name	= MBOCHS_CLASS_NAME "-" MBOCHS_TYPE_2,
+		.type.pretty_name	= MBOCHS_CLASS_NAME "-" MBOCHS_TYPE_2,
  		.mbytes = 16,
  		.max_x  = 1920,
  		.max_y  = 1440,
  	}, {
  		.type.sysfs_name	= MBOCHS_TYPE_3,
-		.name	= MBOCHS_CLASS_NAME "-" MBOCHS_TYPE_3,
+		.type.pretty_name	= MBOCHS_CLASS_NAME "-" MBOCHS_TYPE_3,
  		.mbytes = 64,
  		.max_x  = 0,
  		.max_y  = 0,
@@ -547,7 +546,7 @@ static int mbochs_probe(struct mdev_device *mdev)
  		goto err_mem;
  
  	dev_info(dev, "%s: %s, %d MB, %ld pages\n", __func__,
-		 type->name, type->mbytes, mdev_state->pagecount);
+		 type->type.pretty_name, type->mbytes, mdev_state->pagecount);
  
  	mutex_init(&mdev_state->ops_lock);
  	mdev_state->mdev = mdev;
@@ -1334,16 +1333,6 @@ static const struct attribute_group *mdev_dev_groups[] = {
  	NULL,
  };
  
-static ssize_t name_show(struct mdev_type *mtype,
-			 struct mdev_type_attribute *attr, char *buf)
-{
-	struct mbochs_type *type =
-		container_of(mtype, struct mbochs_type, type);
-
-	return sprintf(buf, "%s\n", type->name);
-}
-static MDEV_TYPE_ATTR_RO(name);
-
  static ssize_t description_show(struct mdev_type *mtype,
  				struct mdev_type_attribute *attr, char *buf)
  {
@@ -1368,7 +1357,6 @@ static ssize_t available_instances_show(struct mdev_type *mtype,
  static MDEV_TYPE_ATTR_RO(available_instances);
  
  static const struct attribute *mdev_types_attrs[] = {
-	&mdev_type_attr_name.attr,
  	&mdev_type_attr_description.attr,
  	&mdev_type_attr_available_instances.attr,
  	NULL,
diff --git a/samples/vfio-mdev/mdpy.c b/samples/vfio-mdev/mdpy.c
index 401a9a622673c..1b2117772192f 100644
--- a/samples/vfio-mdev/mdpy.c
+++ b/samples/vfio-mdev/mdpy.c
@@ -53,7 +53,6 @@ MODULE_PARM_DESC(count, "number of " MDPY_NAME " devices");
  
  static struct mdpy_type {
  	struct mdev_type type;
-	const char *name;
  	u32 format;
  	u32 bytepp;
  	u32 width;
@@ -61,21 +60,21 @@ static struct mdpy_type {
  } mdpy_types[] = {
  	{
  		.type.sysfs_name 	= MDPY_TYPE_1,
-		.name	= MDPY_CLASS_NAME "-" MDPY_TYPE_1,
+		.type.pretty_name	= MDPY_CLASS_NAME "-" MDPY_TYPE_1,
  		.format = DRM_FORMAT_XRGB8888,
  		.bytepp = 4,
  		.width	= 640,
  		.height = 480,
  	}, {
  		.type.sysfs_name 	= MDPY_TYPE_2,
-		.name	= MDPY_CLASS_NAME "-" MDPY_TYPE_2,
+		.type.pretty_name	= MDPY_CLASS_NAME "-" MDPY_TYPE_2,
  		.format = DRM_FORMAT_XRGB8888,
  		.bytepp = 4,
  		.width	= 1024,
  		.height = 768,
  	}, {
  		.type.sysfs_name 	= MDPY_TYPE_3,
-		.name	= MDPY_CLASS_NAME "-" MDPY_TYPE_3,
+		.type.pretty_name	= MDPY_CLASS_NAME "-" MDPY_TYPE_3,
  		.format = DRM_FORMAT_XRGB8888,
  		.bytepp = 4,
  		.width	= 1920,
@@ -256,8 +255,8 @@ static int mdpy_probe(struct mdev_device *mdev)
  		ret = -ENOMEM;
  		goto err_vconfig;
  	}
-	dev_info(dev, "%s: %s (%dx%d)\n", __func__, type->name, type->width,
-		 type->height);
+	dev_info(dev, "%s: %s (%dx%d)\n", __func__, type->type.pretty_name,
+		 type->width, type->height);
  
  	mutex_init(&mdev_state->ops_lock);
  	mdev_state->mdev = mdev;
@@ -651,15 +650,6 @@ static const struct attribute_group *mdev_dev_groups[] = {
  	NULL,
  };
  
-static ssize_t name_show(struct mdev_type *mtype,
-			 struct mdev_type_attribute *attr, char *buf)
-{
-	struct mdpy_type *type = container_of(mtype, struct mdpy_type, type);
-
-	return sprintf(buf, "%s\n", type->name);
-}
-static MDEV_TYPE_ATTR_RO(name);
-
  static ssize_t description_show(struct mdev_type *mtype,
  				struct mdev_type_attribute *attr, char *buf)
  {
@@ -679,7 +669,6 @@ static ssize_t available_instances_show(struct mdev_type *mtype,
  static MDEV_TYPE_ATTR_RO(available_instances);
  
  static const struct attribute *mdev_types_attrs[] = {
-	&mdev_type_attr_name.attr,
  	&mdev_type_attr_description.attr,
  	&mdev_type_attr_available_instances.attr,
  	NULL,
diff --git a/samples/vfio-mdev/mtty.c b/samples/vfio-mdev/mtty.c
index 2a470424628af..b95a4491265c5 100644
--- a/samples/vfio-mdev/mtty.c
+++ b/samples/vfio-mdev/mtty.c
@@ -146,10 +146,11 @@ struct mdev_state {
  static struct mtty_type {
  	struct mdev_type type;
  	int nr_ports;
-	const char *name;
  } mtty_types[2] = {
-	{ .nr_ports = 1, .type.sysfs_name = "1", .name = "Single port serial" },
-	{ .nr_ports = 2, .type.sysfs_name = "2", .name = "Dual port serial" },
+	{ .nr_ports = 1, .type.sysfs_name = "1",
+	  .type.pretty_name = "Single port serial" },
+	{ .nr_ports = 2, .type.sysfs_name = "2",
+	  .type.pretty_name = "Dual port serial" },
  };
  
  static struct mdev_type *mtty_mdev_types[] = {
@@ -1246,16 +1247,6 @@ static const struct attribute_group *mdev_dev_groups[] = {
  	NULL,
  };
  
-static ssize_t name_show(struct mdev_type *mtype,
-			 struct mdev_type_attribute *attr, char *buf)
-{
-	struct mtty_type *type = container_of(mtype, struct mtty_type, type);
-
-	return sysfs_emit(buf, "%s\n", type->name);
-}
-
-static MDEV_TYPE_ATTR_RO(name);
-
  static ssize_t available_instances_show(struct mdev_type *mtype,
  					struct mdev_type_attribute *attr,
  					char *buf)
@@ -1269,7 +1260,6 @@ static ssize_t available_instances_show(struct mdev_type *mtype,
  static MDEV_TYPE_ATTR_RO(available_instances);
  
  static const struct attribute *mdev_types_attrs[] = {
-	&mdev_type_attr_name.attr,
  	&mdev_type_attr_available_instances.attr,
  	NULL,
  };






