The NetDIM library, currently leveraged by an array of NICs, delivers
excellent acceleration benefits. Nevertheless, NICs vary significantly
in their dim profile list prerequisites.

Specifically, virtio-net backends may present diverse sw or hw device
implementation, making a one-size-fits-all parameter list impractical.
On Alibaba Cloud, the virtio DPU's performance under the default DIM
profile falls short of expectations, partly due to a mismatch in
parameter configuration.

I also noticed that ice/idpf/ena and other NICs have customized
profilelist or placed some restrictions on dim capabilities.

Motivated by this, I tried adding new params for "ethtool -C" that provides
a per-device control to modify and access a device's interrupt parameters.

Usage
========
The target NIC is named ethx.

Assume that ethx only declares support for rx profile setting
(with DIM_PROFILE_RX flag set in profile_flags) and supports modification
of usec and pkt fields.

1. Query the currently customized list of the device

$ ethtool -c ethx
...
rx-profile:
{.usec =   1, .pkts = 256, .comps = n/a,},
{.usec =   8, .pkts = 256, .comps = n/a,},
{.usec =  64, .pkts = 256, .comps = n/a,},
{.usec = 128, .pkts = 256, .comps = n/a,},
{.usec = 256, .pkts = 256, .comps = n/a,}
tx-profile:   n/a

2. Tune
$ ethtool -C ethx rx-profile 1,1,n_2,n,n_3,3,n_4,4,n_n,5,n
"n" means do not modify this field.
$ ethtool -c ethx
...
rx-profile:
{.usec =   1, .pkts =   1, .comps = n/a,},
{.usec =   2, .pkts = 256, .comps = n/a,},
{.usec =   3, .pkts =   3, .comps = n/a,},
{.usec =   4, .pkts =   4, .comps = n/a,},
{.usec = 256, .pkts =   5, .comps = n/a,}
tx-profile:   n/a

3. Hint
If the device does not support some type of customized dim profiles,
the corresponding "n/a" will display.

If the "n/a" field is being modified, -EOPNOTSUPP will be reported.

Signed-off-by: Heng Qi <hen...@linux.alibaba.com>
Reviewed-by: Simon Horman <ho...@kernel.org>
---
 Documentation/netlink/specs/ethtool.yaml     |  31 +++
 Documentation/networking/ethtool-netlink.rst |   8 +
 Documentation/networking/net_dim.rst         |  42 +++
 include/linux/dim.h                          |  58 ++++
 include/linux/ethtool.h                      |   4 +-
 include/linux/netdevice.h                    |   3 +
 include/uapi/linux/ethtool_netlink.h         |  22 ++
 lib/dim/net_dim.c                            |  70 +++++
 net/Kconfig                                  |   1 +
 net/ethtool/coalesce.c                       | 273 ++++++++++++++++++-
 10 files changed, 509 insertions(+), 3 deletions(-)

diff --git a/Documentation/netlink/specs/ethtool.yaml 
b/Documentation/netlink/specs/ethtool.yaml
index 00dc61358be8..6c2ab3d1c22f 100644
--- a/Documentation/netlink/specs/ethtool.yaml
+++ b/Documentation/netlink/specs/ethtool.yaml
@@ -414,6 +414,26 @@ attribute-sets:
         name: combined-count
         type: u32
 
+  -
+    name: irq-moderation
+    attributes:
+      -
+        name: usec
+        type: u32
+      -
+        name: pkts
+        type: u32
+      -
+        name: comps
+        type: u32
+  -
+    name: profile
+    attributes:
+      -
+        name: irq-moderation
+        type: nest
+        multi-attr: true
+        nested-attributes: irq-moderation
   -
     name: coalesce
     attributes:
@@ -502,6 +522,15 @@ attribute-sets:
       -
         name: tx-aggr-time-usecs
         type: u32
+      -
+        name: rx-profile
+        type: nest
+        nested-attributes: profile
+      -
+        name: tx-profile
+        type: nest
+        nested-attributes: profile
+
   -
     name: pause-stat
     attributes:
@@ -1325,6 +1354,8 @@ operations:
             - tx-aggr-max-bytes
             - tx-aggr-max-frames
             - tx-aggr-time-usecs
+            - rx-profile
+            - tx-profile
       dump: *coalesce-get-op
     -
       name: coalesce-set
diff --git a/Documentation/networking/ethtool-netlink.rst 
b/Documentation/networking/ethtool-netlink.rst
index 160bfb0ae8ba..7ec08e903bab 100644
--- a/Documentation/networking/ethtool-netlink.rst
+++ b/Documentation/networking/ethtool-netlink.rst
@@ -1033,6 +1033,8 @@ Kernel response contents:
   ``ETHTOOL_A_COALESCE_TX_AGGR_MAX_BYTES``     u32     max aggr size, Tx
   ``ETHTOOL_A_COALESCE_TX_AGGR_MAX_FRAMES``    u32     max aggr packets, Tx
   ``ETHTOOL_A_COALESCE_TX_AGGR_TIME_USECS``    u32     time (us), aggr, Tx
+  ``ETHTOOL_A_COALESCE_RX_PROFILE``            nested  profile of DIM, Rx
+  ``ETHTOOL_A_COALESCE_TX_PROFILE``            nested  profile of DIM, Tx
   ===========================================  ======  =======================
 
 Attributes are only included in reply if their value is not zero or the
@@ -1062,6 +1064,10 @@ block should be sent.
 This feature is mainly of interest for specific USB devices which does not cope
 well with frequent small-sized URBs transmissions.
 
+``ETHTOOL_A_COALESCE_RX_PROFILE`` and ``ETHTOOL_A_COALESCE_TX_PROFILE`` refer
+to DIM parameters, see `Generic Network Dynamic Interrupt Moderation (Net DIM)
+<https://www.kernel.org/doc/Documentation/networking/net_dim.rst>`_.
+
 COALESCE_SET
 ============
 
@@ -1098,6 +1104,8 @@ Request contents:
   ``ETHTOOL_A_COALESCE_TX_AGGR_MAX_BYTES``     u32     max aggr size, Tx
   ``ETHTOOL_A_COALESCE_TX_AGGR_MAX_FRAMES``    u32     max aggr packets, Tx
   ``ETHTOOL_A_COALESCE_TX_AGGR_TIME_USECS``    u32     time (us), aggr, Tx
+  ``ETHTOOL_A_COALESCE_RX_PROFILE``            nested  profile of DIM, Rx
+  ``ETHTOOL_A_COALESCE_TX_PROFILE``            nested  profile of DIM, Tx
   ===========================================  ======  =======================
 
 Request is rejected if it attributes declared as unsupported by driver (i.e.
diff --git a/Documentation/networking/net_dim.rst 
b/Documentation/networking/net_dim.rst
index 3bed9fd95336..8908fd7b0a8d 100644
--- a/Documentation/networking/net_dim.rst
+++ b/Documentation/networking/net_dim.rst
@@ -169,6 +169,48 @@ usage is not complete but it should make the outline of 
the usage clear.
        ...
   }
 
+
+Tuning DIM
+==========
+
+Net DIM serves a range of network devices and delivers excellent acceleration
+benefits. Yet, it has been observed that some preset configurations of DIM may
+not align seamlessly with the varying specifications of network devices, and
+this discrepancy has been identified as a factor to the suboptimal performance
+outcomes of DIM-enabled network devices, related to a mismatch in profiles.
+
+To address this issue, Net DIM introduces a per-device control to modify and
+access a device's ``rx-profile`` and ``tx-profile`` parameters:
+Assume that the target network device is named ethx, and ethx only declares
+support for RX profile setting and supports modification of ``usec`` field
+and ``pkts`` field (See the data structure:
+:c:type:`struct dim_cq_moder <dim_cq_moder>`).
+
+You can use ethtool to modify the current RX DIM profile where all
+values are 64::
+
+    $ ethtool -C ethx rx-profile 1,1,n_2,2,n_3,n,n_n,4,n_n,n,n
+
+``n`` means do not modify this field, and ``_`` separates structure
+elements of the profile array.
+
+Querying the current profiles using::
+
+    $ ethtool -c ethx
+    ...
+    rx-profile:
+    {.usec =   1, .pkts =   1, .comps = n/a,},
+    {.usec =   2, .pkts =   2, .comps = n/a,},
+    {.usec =   3, .pkts =  64, .comps = n/a,},
+    {.usec =  64, .pkts =   4, .comps = n/a,},
+    {.usec =  64, .pkts =  64, .comps = n/a,}
+    tx-profile:   n/a
+
+If the network device does not support specific fields of DIM profiles,
+the corresponding ``n/a`` will display. If the ``n/a`` field is being
+modified, error messages will be reported.
+
+
 Dynamic Interrupt Moderation (DIM) library API
 ==============================================
 
diff --git a/include/linux/dim.h b/include/linux/dim.h
index 43398f5eade2..e0f39bd85432 100644
--- a/include/linux/dim.h
+++ b/include/linux/dim.h
@@ -10,6 +10,8 @@
 #include <linux/types.h>
 #include <linux/workqueue.h>
 
+struct net_device;
+
 /* Number of DIM profiles and period mode. */
 #define NET_DIM_PARAMS_NUM_PROFILES 5
 #define NET_DIM_DEFAULT_RX_CQ_PKTS_FROM_EQE 256
@@ -45,12 +47,45 @@
  * @pkts: CQ packet counter suggestion (by DIM)
  * @comps: Completion counter
  * @cq_period_mode: CQ period count mode (from CQE/EQE)
+ * @rcu: for asynchronous kfree_rcu
  */
 struct dim_cq_moder {
        u16 usec;
        u16 pkts;
        u16 comps;
        u8 cq_period_mode;
+       struct rcu_head rcu;
+};
+
+#define DIM_PROFILE_RX         BIT(0)  /* support rx profile modification */
+#define DIM_PROFILE_TX         BIT(1)  /* support tx profile modification */
+
+#define DIM_COALESCE_USEC      BIT(0)  /* support usec field modification */
+#define DIM_COALESCE_PKTS      BIT(1)  /* support pkts field modification */
+#define DIM_COALESCE_COMPS     BIT(2)  /* support comps field modification */
+
+/**
+ * struct dim_irq_moder - Structure for irq moderation information.
+ * Used to collect irq moderation related information.
+ *
+ * @profile_flags: DIM_PROFILE_*
+ * @coal_flags: DIM_COALESCE_* for Rx and Tx
+ * @dim_rx_mode: Rx DIM period count mode: CQE or EQE
+ * @dim_tx_mode: Tx DIM period count mode: CQE or EQE
+ * @rx_profile: DIM profile list for Rx
+ * @tx_profile: DIM profile list for Tx
+ * @rx_dim_work: Rx DIM worker scheduled by net_dim()
+ * @tx_dim_work: Tx DIM worker scheduled by net_dim()
+ */
+struct dim_irq_moder {
+       u8 profile_flags;
+       u8 coal_flags;
+       u8 dim_rx_mode;
+       u8 dim_tx_mode;
+       struct dim_cq_moder __rcu *rx_profile;
+       struct dim_cq_moder __rcu *tx_profile;
+       void (*rx_dim_work)(struct work_struct *work);
+       void (*tx_dim_work)(struct work_struct *work);
 };
 
 /**
@@ -198,6 +233,29 @@ enum dim_step_result {
        DIM_ON_EDGE,
 };
 
+/**
+ * net_dim_init_irq_moder - collect information to initialize irq moderation
+ * @dev: target network device
+ * @profile_flags: Rx or Tx profile modification capability
+ * @coal_flags: irq moderation params flags
+ * @rx_mode: CQ period mode for Rx
+ * @tx_mode: CQ period mode for Tx
+ * @rx_dim_work: Rx worker called after dim decision
+ * @tx_dim_work: Tx worker called after dim decision
+ *
+ * Return: 0 on success or a negative error code.
+ */
+int net_dim_init_irq_moder(struct net_device *dev, u8 profile_flags,
+                          u8 coal_flags, u8 rx_mode, u8 tx_mode,
+                          void (*rx_dim_work)(struct work_struct *work),
+                          void (*tx_dim_work)(struct work_struct *work));
+
+/**
+ * net_dim_free_irq_moder - free fields for irq moderation
+ * @dev: target network device
+ */
+void net_dim_free_irq_moder(struct net_device *dev);
+
 /**
  *     dim_on_top - check if current state is a good place to stop (top 
location)
  *     @dim: DIM context
diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index 6fd9107d3cc0..959196af7f5a 100644
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -284,7 +284,9 @@ bool ethtool_convert_link_mode_to_legacy_u32(u32 
*legacy_u32,
 #define ETHTOOL_COALESCE_TX_AGGR_MAX_BYTES     BIT(24)
 #define ETHTOOL_COALESCE_TX_AGGR_MAX_FRAMES    BIT(25)
 #define ETHTOOL_COALESCE_TX_AGGR_TIME_USECS    BIT(26)
-#define ETHTOOL_COALESCE_ALL_PARAMS            GENMASK(26, 0)
+#define ETHTOOL_COALESCE_RX_PROFILE            BIT(27)
+#define ETHTOOL_COALESCE_TX_PROFILE            BIT(28)
+#define ETHTOOL_COALESCE_ALL_PARAMS            GENMASK(28, 0)
 
 #define ETHTOOL_COALESCE_USECS                                         \
        (ETHTOOL_COALESCE_RX_USECS | ETHTOOL_COALESCE_TX_USECS)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index c83b390191d4..983ef1935c38 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -2401,6 +2401,9 @@ struct net_device {
        /** @page_pools: page pools created for this netdevice */
        struct hlist_head       page_pools;
 #endif
+
+       /** @irq_moder: dim parameters used if IS_ENABLED(CONFIG_DIMLIB). */
+       struct dim_irq_moder    *irq_moder;
 };
 #define to_net_dev(d) container_of(d, struct net_device, dev)
 
diff --git a/include/uapi/linux/ethtool_netlink.h 
b/include/uapi/linux/ethtool_netlink.h
index b49b804b9495..d15856c7e001 100644
--- a/include/uapi/linux/ethtool_netlink.h
+++ b/include/uapi/linux/ethtool_netlink.h
@@ -415,12 +415,34 @@ enum {
        ETHTOOL_A_COALESCE_TX_AGGR_MAX_BYTES,           /* u32 */
        ETHTOOL_A_COALESCE_TX_AGGR_MAX_FRAMES,          /* u32 */
        ETHTOOL_A_COALESCE_TX_AGGR_TIME_USECS,          /* u32 */
+       /* nest - _A_PROFILE_IRQ_MODERATION */
+       ETHTOOL_A_COALESCE_RX_PROFILE,
+       /* nest - _A_PROFILE_IRQ_MODERATION */
+       ETHTOOL_A_COALESCE_TX_PROFILE,
 
        /* add new constants above here */
        __ETHTOOL_A_COALESCE_CNT,
        ETHTOOL_A_COALESCE_MAX = (__ETHTOOL_A_COALESCE_CNT - 1)
 };
 
+enum {
+       ETHTOOL_A_PROFILE_UNSPEC,
+       /* nest, _A_IRQ_MODERATION_* */
+       ETHTOOL_A_PROFILE_IRQ_MODERATION,
+       __ETHTOOL_A_PROFILE_CNT,
+       ETHTOOL_A_PROFILE_MAX = (__ETHTOOL_A_PROFILE_CNT - 1)
+};
+
+enum {
+       ETHTOOL_A_IRQ_MODERATION_UNSPEC,
+       ETHTOOL_A_IRQ_MODERATION_USEC,                  /* u32 */
+       ETHTOOL_A_IRQ_MODERATION_PKTS,                  /* u32 */
+       ETHTOOL_A_IRQ_MODERATION_COMPS,                 /* u32 */
+
+       __ETHTOOL_A_IRQ_MODERATION_CNT,
+       ETHTOOL_A_IRQ_MODERATION_MAX = (__ETHTOOL_A_IRQ_MODERATION_CNT - 1)
+};
+
 /* PAUSE */
 
 enum {
diff --git a/lib/dim/net_dim.c b/lib/dim/net_dim.c
index 67d5beb34dc3..0cd41277c7a3 100644
--- a/lib/dim/net_dim.c
+++ b/lib/dim/net_dim.c
@@ -4,6 +4,7 @@
  */
 
 #include <linux/dim.h>
+#include <linux/rtnetlink.h>
 
 /*
  * Net DIM profiles:
@@ -95,6 +96,75 @@ net_dim_get_def_tx_moderation(u8 cq_period_mode)
 }
 EXPORT_SYMBOL(net_dim_get_def_tx_moderation);
 
+int net_dim_init_irq_moder(struct net_device *dev, u8 profile_flags,
+                          u8 coal_flags, u8 rx_mode, u8 tx_mode,
+                          void (*rx_dim_work)(struct work_struct *work),
+                          void (*tx_dim_work)(struct work_struct *work))
+{
+       struct dim_cq_moder *rxp = NULL, *txp;
+       struct dim_irq_moder *moder;
+       int len;
+
+       dev->irq_moder = kzalloc(sizeof(*dev->irq_moder), GFP_KERNEL);
+       if (!dev->irq_moder)
+               return -ENOMEM;
+
+       moder = dev->irq_moder;
+       len = NET_DIM_PARAMS_NUM_PROFILES * sizeof(*moder->rx_profile);
+
+       moder->coal_flags = coal_flags;
+       moder->profile_flags = profile_flags;
+
+       if (profile_flags & DIM_PROFILE_RX) {
+               moder->rx_dim_work = rx_dim_work;
+               moder->dim_rx_mode = rx_mode;
+               rxp = kmemdup(rx_profile[rx_mode], len, GFP_KERNEL);
+               if (!rxp)
+                       goto free_moder;
+
+               rcu_assign_pointer(moder->rx_profile, rxp);
+       }
+
+       if (profile_flags & DIM_PROFILE_TX) {
+               moder->tx_dim_work = tx_dim_work;
+               moder->dim_tx_mode = tx_mode;
+               txp = kmemdup(tx_profile[tx_mode], len, GFP_KERNEL);
+               if (!txp)
+                       goto free_rxp;
+
+               rcu_assign_pointer(moder->tx_profile, txp);
+       }
+
+       return 0;
+
+free_rxp:
+       kfree(rxp);
+free_moder:
+       kfree(moder);
+       return -ENOMEM;
+}
+EXPORT_SYMBOL(net_dim_init_irq_moder);
+
+/* RTNL lock is held. */
+void net_dim_free_irq_moder(struct net_device *dev)
+{
+       struct dim_cq_moder *rxp, *txp;
+
+       if (!dev->irq_moder)
+               return;
+
+       rxp = rtnl_dereference(dev->irq_moder->rx_profile);
+       txp = rtnl_dereference(dev->irq_moder->tx_profile);
+
+       rcu_assign_pointer(dev->irq_moder->rx_profile, NULL);
+       rcu_assign_pointer(dev->irq_moder->tx_profile, NULL);
+
+       kfree_rcu(rxp, rcu);
+       kfree_rcu(txp, rcu);
+       kfree(dev->irq_moder);
+}
+EXPORT_SYMBOL(net_dim_free_irq_moder);
+
 static int net_dim_step(struct dim *dim)
 {
        if (dim->tired == (NET_DIM_PARAMS_NUM_PROFILES * 2))
diff --git a/net/Kconfig b/net/Kconfig
index 9fe65fa26e48..d27d0deac0bf 100644
--- a/net/Kconfig
+++ b/net/Kconfig
@@ -508,6 +508,7 @@ config FAILOVER
 
 config ETHTOOL_NETLINK
        bool "Netlink interface for ethtool"
+       select DIMLIB
        default y
        help
          An alternative userspace interface for ethtool based on generic
diff --git a/net/ethtool/coalesce.c b/net/ethtool/coalesce.c
index 83112c1a71ae..759b16e3d134 100644
--- a/net/ethtool/coalesce.c
+++ b/net/ethtool/coalesce.c
@@ -1,5 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-only
 
+#include <linux/dim.h>
 #include "netlink.h"
 #include "common.h"
 
@@ -82,6 +83,14 @@ static int coalesce_prepare_data(const struct ethnl_req_info 
*req_base,
 static int coalesce_reply_size(const struct ethnl_req_info *req_base,
                               const struct ethnl_reply_data *reply_base)
 {
+       int modersz = nla_total_size(0) + /* _PROFILE_IRQ_MODERATION, nest */
+                     nla_total_size(sizeof(u32)) + /* _IRQ_MODERATION_USEC */
+                     nla_total_size(sizeof(u32)) + /* _IRQ_MODERATION_PKTS */
+                     nla_total_size(sizeof(u32));  /* _IRQ_MODERATION_COMPS */
+
+       int total_modersz = nla_total_size(0) +  /* _{R,T}X_PROFILE, nest */
+                       modersz * NET_DIM_PARAMS_NUM_PROFILES;
+
        return nla_total_size(sizeof(u32)) +    /* _RX_USECS */
               nla_total_size(sizeof(u32)) +    /* _RX_MAX_FRAMES */
               nla_total_size(sizeof(u32)) +    /* _RX_USECS_IRQ */
@@ -108,7 +117,8 @@ static int coalesce_reply_size(const struct ethnl_req_info 
*req_base,
               nla_total_size(sizeof(u8)) +     /* _USE_CQE_MODE_RX */
               nla_total_size(sizeof(u32)) +    /* _TX_AGGR_MAX_BYTES */
               nla_total_size(sizeof(u32)) +    /* _TX_AGGR_MAX_FRAMES */
-              nla_total_size(sizeof(u32));     /* _TX_AGGR_TIME_USECS */
+              nla_total_size(sizeof(u32)) +    /* _TX_AGGR_TIME_USECS */
+              total_modersz * 2;               /* _{R,T}X_PROFILE */
 }
 
 static bool coalesce_put_u32(struct sk_buff *skb, u16 attr_type, u32 val,
@@ -127,14 +137,84 @@ static bool coalesce_put_bool(struct sk_buff *skb, u16 
attr_type, u32 val,
        return nla_put_u8(skb, attr_type, !!val);
 }
 
+/**
+ * coalesce_put_profile - fill reply with a nla nest with four child nla nests.
+ * @skb: socket buffer the message is stored in
+ * @attr_type: nest attr type ETHTOOL_A_COALESCE_*X_PROFILE
+ * @profile: data passed to userspace
+ * @coal_flags: modifiable parameters supported by the driver
+ *
+ * Put a dim profile nest attribute. Refer to ETHTOOL_A_PROFILE_IRQ_MODERATION.
+ *
+ * Return: 0 on success or a negative error code.
+ */
+static int coalesce_put_profile(struct sk_buff *skb, u16 attr_type,
+                               const struct dim_cq_moder *profile,
+                               u8 coal_flags)
+{
+       struct nlattr *profile_attr, *moder_attr;
+       int i, ret;
+
+       if (!profile || !coal_flags)
+               return 0;
+
+       profile_attr = nla_nest_start(skb, attr_type);
+       if (!profile_attr)
+               return -EMSGSIZE;
+
+       for (i = 0; i < NET_DIM_PARAMS_NUM_PROFILES; i++) {
+               moder_attr = nla_nest_start(skb,
+                                           ETHTOOL_A_PROFILE_IRQ_MODERATION);
+               if (!moder_attr) {
+                       ret = -EMSGSIZE;
+                       goto cancel_profile;
+               }
+
+               if (coal_flags & DIM_COALESCE_USEC) {
+                       ret = nla_put_u32(skb, ETHTOOL_A_IRQ_MODERATION_USEC,
+                                         profile[i].usec);
+                       if (ret)
+                               goto cancel_moder;
+               }
+
+               if (coal_flags & DIM_COALESCE_PKTS) {
+                       ret = nla_put_u32(skb, ETHTOOL_A_IRQ_MODERATION_PKTS,
+                                         profile[i].pkts);
+                       if (ret)
+                               goto cancel_moder;
+               }
+
+               if (coal_flags & DIM_COALESCE_COMPS) {
+                       ret = nla_put_u32(skb, ETHTOOL_A_IRQ_MODERATION_COMPS,
+                                         profile[i].comps);
+                       if (ret)
+                               goto cancel_moder;
+               }
+
+               nla_nest_end(skb, moder_attr);
+       }
+
+       nla_nest_end(skb, profile_attr);
+
+       return 0;
+
+cancel_moder:
+       nla_nest_cancel(skb, moder_attr);
+cancel_profile:
+       nla_nest_cancel(skb, profile_attr);
+       return ret;
+}
+
 static int coalesce_fill_reply(struct sk_buff *skb,
                               const struct ethnl_req_info *req_base,
                               const struct ethnl_reply_data *reply_base)
 {
        const struct coalesce_reply_data *data = COALESCE_REPDATA(reply_base);
        const struct kernel_ethtool_coalesce *kcoal = &data->kernel_coalesce;
+       struct dim_irq_moder *moder = req_base->dev->irq_moder;
        const struct ethtool_coalesce *coal = &data->coalesce;
        u32 supported = data->supported_params;
+       int ret = 0;
 
        if (coalesce_put_u32(skb, ETHTOOL_A_COALESCE_RX_USECS,
                             coal->rx_coalesce_usecs, supported) ||
@@ -192,11 +272,41 @@ static int coalesce_fill_reply(struct sk_buff *skb,
                             kcoal->tx_aggr_time_usecs, supported))
                return -EMSGSIZE;
 
-       return 0;
+       if (!moder)
+               return 0;
+
+       rcu_read_lock();
+       if (moder->profile_flags & DIM_PROFILE_RX) {
+               ret = coalesce_put_profile(skb, ETHTOOL_A_COALESCE_RX_PROFILE,
+                                          rcu_dereference(moder->rx_profile),
+                                          moder->coal_flags);
+               if (ret)
+                       goto out;
+       }
+
+       if (moder->profile_flags & DIM_PROFILE_TX)
+               ret = coalesce_put_profile(skb, ETHTOOL_A_COALESCE_TX_PROFILE,
+                                          rcu_dereference(moder->tx_profile),
+                                          moder->coal_flags);
+
+out:
+       rcu_read_unlock();
+       return ret;
 }
 
 /* COALESCE_SET */
 
+static const struct nla_policy coalesce_irq_moderation_policy[] = {
+       [ETHTOOL_A_IRQ_MODERATION_USEC] = { .type = NLA_U32 },
+       [ETHTOOL_A_IRQ_MODERATION_PKTS] = { .type = NLA_U32 },
+       [ETHTOOL_A_IRQ_MODERATION_COMPS] = { .type = NLA_U32 },
+};
+
+static const struct nla_policy coalesce_profile_policy[] = {
+       [ETHTOOL_A_PROFILE_IRQ_MODERATION] =
+               NLA_POLICY_NESTED(coalesce_irq_moderation_policy),
+};
+
 const struct nla_policy ethnl_coalesce_set_policy[] = {
        [ETHTOOL_A_COALESCE_HEADER]             =
                NLA_POLICY_NESTED(ethnl_header_policy),
@@ -227,6 +337,10 @@ const struct nla_policy ethnl_coalesce_set_policy[] = {
        [ETHTOOL_A_COALESCE_TX_AGGR_MAX_BYTES] = { .type = NLA_U32 },
        [ETHTOOL_A_COALESCE_TX_AGGR_MAX_FRAMES] = { .type = NLA_U32 },
        [ETHTOOL_A_COALESCE_TX_AGGR_TIME_USECS] = { .type = NLA_U32 },
+       [ETHTOOL_A_COALESCE_RX_PROFILE] =
+               NLA_POLICY_NESTED(coalesce_profile_policy),
+       [ETHTOOL_A_COALESCE_TX_PROFILE] =
+               NLA_POLICY_NESTED(coalesce_profile_policy),
 };
 
 static int
@@ -234,6 +348,7 @@ ethnl_set_coalesce_validate(struct ethnl_req_info *req_info,
                            struct genl_info *info)
 {
        const struct ethtool_ops *ops = req_info->dev->ethtool_ops;
+       struct dim_irq_moder *irq_moder = req_info->dev->irq_moder;
        struct nlattr **tb = info->attrs;
        u32 supported_params;
        u16 a;
@@ -243,6 +358,12 @@ ethnl_set_coalesce_validate(struct ethnl_req_info 
*req_info,
 
        /* make sure that only supported parameters are present */
        supported_params = ops->supported_coalesce_params;
+       if (irq_moder && irq_moder->profile_flags & DIM_PROFILE_RX)
+               supported_params |= ETHTOOL_COALESCE_RX_PROFILE;
+
+       if (irq_moder && irq_moder->profile_flags & DIM_PROFILE_TX)
+               supported_params |= ETHTOOL_COALESCE_TX_PROFILE;
+
        for (a = ETHTOOL_A_COALESCE_RX_USECS; a < __ETHTOOL_A_COALESCE_CNT; a++)
                if (tb[a] && !(supported_params & attr_to_mask(a))) {
                        NL_SET_ERR_MSG_ATTR(info->extack, tb[a],
@@ -253,6 +374,138 @@ ethnl_set_coalesce_validate(struct ethnl_req_info 
*req_info,
        return 1;
 }
 
+/**
+ * ethnl_update_irq_moder - update a specific field in the given profile
+ * @irq_moder: place that collects dim related information
+ * @irq_field: field in profile to modify
+ * @attr_type: attr type ETHTOOL_A_IRQ_MODERATION_*
+ * @tb: netlink attribute with new values or null
+ * @coal_bit: DIM_COALESCE_* bit from coal_flags
+ * @mod: pointer to bool for modification tracking
+ * @extack: netlink extended ack
+ *
+ * Return: 0 on success or a negative error code.
+ */
+static int ethnl_update_irq_moder(struct dim_irq_moder *irq_moder,
+                                 u16 *irq_field, u16 attr_type,
+                                 struct nlattr **tb,
+                                 u8 coal_bit, bool *mod,
+                                 struct netlink_ext_ack *extack)
+{
+       int ret = 0;
+       u32 val;
+
+       if (!tb[attr_type])
+               return 0;
+
+       if (irq_moder->coal_flags & coal_bit) {
+               val = nla_get_u32(tb[attr_type]);
+               if (*irq_field == val)
+                       return 0;
+
+               *irq_field = val;
+               *mod = true;
+       } else {
+               NL_SET_BAD_ATTR(extack, tb[attr_type]);
+               ret = -EOPNOTSUPP;
+       }
+
+       return ret;
+}
+
+/**
+ * ethnl_update_profile - get a profile nest with child nests from userspace.
+ * @dev: netdevice to update the profile
+ * @dst: profile get from the driver and modified by ethnl_update_profile.
+ * @nests: nest attr ETHTOOL_A_COALESCE_*X_PROFILE to set profile.
+ * @mod: pointer to bool for modification tracking
+ * @extack: Netlink extended ack
+ *
+ * Layout of nests:
+ *   Nested ETHTOOL_A_COALESCE_*X_PROFILE attr
+ *     Nested ETHTOOL_A_PROFILE_IRQ_MODERATION attr
+ *       ETHTOOL_A_IRQ_MODERATION_USEC attr
+ *       ETHTOOL_A_IRQ_MODERATION_PKTS attr
+ *       ETHTOOL_A_IRQ_MODERATION_COMPS attr
+ *     ...
+ *     Nested ETHTOOL_A_PROFILE_IRQ_MODERATION attr
+ *       ETHTOOL_A_IRQ_MODERATION_USEC attr
+ *       ETHTOOL_A_IRQ_MODERATION_PKTS attr
+ *       ETHTOOL_A_IRQ_MODERATION_COMPS attr
+ *
+ * Return: 0 on success or a negative error code.
+ */
+static int ethnl_update_profile(struct net_device *dev,
+                               struct dim_cq_moder __rcu **dst,
+                               const struct nlattr *nests,
+                               bool *mod,
+                               struct netlink_ext_ack *extack)
+{
+       int len_irq_moder = ARRAY_SIZE(coalesce_irq_moderation_policy);
+       struct nlattr *tb[ARRAY_SIZE(coalesce_irq_moderation_policy)];
+       struct dim_irq_moder *irq_moder = dev->irq_moder;
+       struct dim_cq_moder *new_profile, *old_profile;
+       int ret, rem, i = 0, len;
+       struct nlattr *nest;
+
+       if (!nests)
+               return 0;
+
+       if (!*dst)
+               return -EOPNOTSUPP;
+
+       old_profile = rtnl_dereference(*dst);
+       len = NET_DIM_PARAMS_NUM_PROFILES * sizeof(*old_profile);
+       new_profile = kmemdup(old_profile, len, GFP_KERNEL);
+       if (!new_profile)
+               return -ENOMEM;
+
+       nla_for_each_nested_type(nest, ETHTOOL_A_PROFILE_IRQ_MODERATION,
+                                nests, rem) {
+               ret = nla_parse_nested(tb, len_irq_moder - 1, nest,
+                                      coalesce_irq_moderation_policy,
+                                      extack);
+               if (ret)
+                       goto err_out;
+
+               ret = ethnl_update_irq_moder(irq_moder, &new_profile[i].usec,
+                                            ETHTOOL_A_IRQ_MODERATION_USEC,
+                                            tb, DIM_COALESCE_USEC,
+                                            mod, extack);
+               if (ret)
+                       goto err_out;
+
+               ret = ethnl_update_irq_moder(irq_moder, &new_profile[i].pkts,
+                                            ETHTOOL_A_IRQ_MODERATION_PKTS,
+                                            tb, DIM_COALESCE_PKTS,
+                                            mod, extack);
+               if (ret)
+                       goto err_out;
+
+               ret = ethnl_update_irq_moder(irq_moder, &new_profile[i].comps,
+                                            ETHTOOL_A_IRQ_MODERATION_COMPS,
+                                            tb, DIM_COALESCE_COMPS,
+                                            mod, extack);
+               if (ret)
+                       goto err_out;
+
+               i++;
+       }
+
+       /* After the profile is modified, dim itself is a dynamic
+        * mechanism and will quickly fit to the appropriate
+        * coalescing parameters according to the new profile.
+        */
+       rcu_assign_pointer(*dst, new_profile);
+       kfree_rcu(old_profile, rcu);
+
+       return 0;
+
+err_out:
+       kfree(new_profile);
+       return ret;
+}
+
 static int
 __ethnl_set_coalesce(struct ethnl_req_info *req_info, struct genl_info *info,
                     bool *dual_change)
@@ -317,6 +570,22 @@ __ethnl_set_coalesce(struct ethnl_req_info *req_info, 
struct genl_info *info,
        ethnl_update_u32(&kernel_coalesce.tx_aggr_time_usecs,
                         tb[ETHTOOL_A_COALESCE_TX_AGGR_TIME_USECS], &mod);
 
+       if (dev->irq_moder && dev->irq_moder->profile_flags & DIM_PROFILE_RX) {
+               ret = ethnl_update_profile(dev, &dev->irq_moder->rx_profile,
+                                          tb[ETHTOOL_A_COALESCE_RX_PROFILE],
+                                          &mod, info->extack);
+               if (ret < 0)
+                       return ret;
+       }
+
+       if (dev->irq_moder && dev->irq_moder->profile_flags & DIM_PROFILE_TX) {
+               ret = ethnl_update_profile(dev, &dev->irq_moder->tx_profile,
+                                          tb[ETHTOOL_A_COALESCE_TX_PROFILE],
+                                          &mod, info->extack);
+               if (ret < 0)
+                       return ret;
+       }
+
        /* Update operation modes */
        ethnl_update_bool32(&coalesce.use_adaptive_rx_coalesce,
                            tb[ETHTOOL_A_COALESCE_USE_ADAPTIVE_RX], &mod_mode);
-- 
2.32.0.3.g01195cf9f


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