We use a two-step process to configure a filter with RSS spreading. First,
the RSS context is allocated and configured using ETHTOOL_SRSSH; this
returns an identifier (rss_context) which can then be passed to subsequent
invocations of ETHTOOL_SRXCLSRLINS to specify that the offset from the RSS
indirection table lookup should be added to the queue number (ring_cookie)
when delivering the packet. Drivers for devices which can only use the
indirection table entry directly (not add it to a base queue number)
should reject rule insertions combining RSS with a nonzero ring_cookie.
Signed-off-by: Edward Cree <ec...@solarflare.com>
---
include/linux/ethtool.h | 5 ++++
include/uapi/linux/ethtool.h | 32 +++++++++++++++++-----
net/core/ethtool.c | 64 +++++++++++++++++++++++++++++++++-----------
3 files changed, 80 insertions(+), 21 deletions(-)
diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index 2ec41a7eb54f..ebe41811ed34 100644
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -371,6 +371,11 @@ struct ethtool_ops {
u8 *hfunc);
int (*set_rxfh)(struct net_device *, const u32 *indir,
const u8 *key, const u8 hfunc);
+ int (*get_rxfh_context)(struct net_device *, u32 *indir, u8 *key,
+ u8 *hfunc, u32 rss_context);
+ int (*set_rxfh_context)(struct net_device *, const u32 *indir,
+ const u8 *key, const u8 hfunc,
+ u32 *rss_context, bool delete);
void (*get_channels)(struct net_device *, struct ethtool_channels *);
int (*set_channels)(struct net_device *, struct ethtool_channels *);
int (*get_dump_flag)(struct net_device *, struct ethtool_dump *);
diff --git a/include/uapi/linux/ethtool.h b/include/uapi/linux/ethtool.h
index 44a0b675a6bc..20da156aaf64 100644
--- a/include/uapi/linux/ethtool.h
+++ b/include/uapi/linux/ethtool.h
@@ -914,12 +914,15 @@ static inline __u64 ethtool_get_flow_spec_ring_vf(__u64
ring_cookie)
* @flow_type: Type of flow to be affected, e.g. %TCP_V4_FLOW
* @data: Command-dependent value
* @fs: Flow classification rule
+ * @rss_context: RSS context to be affected
* @rule_cnt: Number of rules to be affected
* @rule_locs: Array of used rule locations
*
* For %ETHTOOL_GRXFH and %ETHTOOL_SRXFH, @data is a bitmask indicating
* the fields included in the flow hash, e.g. %RXH_IP_SRC. The following
- * structure fields must not be used.
+ * structure fields must not be used, except that if @flow_type includes
+ * the %FLOW_RSS flag, then @rss_context determines which RSS context to
+ * act on.
*
* For %ETHTOOL_GRXRINGS, @data is set to the number of RX rings/queues
* on return.
@@ -931,7 +934,9 @@ static inline __u64 ethtool_get_flow_spec_ring_vf(__u64
ring_cookie)
* set in @data then special location values should not be used.
*
* For %ETHTOOL_GRXCLSRULE, @fs.@location specifies the location of an
- * existing rule on entry and @fs contains the rule on return.
+ * existing rule on entry and @fs contains the rule on return; if
+ * @fs.@flow_type includes the %FLOW_RSS flag, then @rss_context is
+ * filled with the RSS context ID associated with the rule.
*
* For %ETHTOOL_GRXCLSRLALL, @rule_cnt specifies the array size of the
* user buffer for @rule_locs on entry. On return, @data is the size
@@ -942,7 +947,11 @@ static inline __u64 ethtool_get_flow_spec_ring_vf(__u64
ring_cookie)
* For %ETHTOOL_SRXCLSRLINS, @fs specifies the rule to add or update.
* @fs.@location either specifies the location to use or is a special
* location value with %RX_CLS_LOC_SPECIAL flag set. On return,
- * @fs.@location is the actual rule location.
+ * @fs.@location is the actual rule location. If @fs.@flow_type
+ * includes the %FLOW_RSS flag, @rss_context is the RSS context ID to
+ * use for flow spreading traffic which matches this rule. The value
+ * from the rxfh indirection table will be added to @fs.@ring_cookie
+ * to choose which ring to deliver to.
*
* For %ETHTOOL_SRXCLSRLDEL, @fs.@location specifies the location of an
* existing rule on entry.
@@ -963,7 +972,10 @@ struct ethtool_rxnfc {
__u32 flow_type;
__u64 data;
struct ethtool_rx_flow_spec fs;
- __u32 rule_cnt;
+ union {
+ __u32 rule_cnt;
+ __u32 rss_context;
+ };
__u32 rule_locs[0];
};
@@ -990,7 +1002,11 @@ struct ethtool_rxfh_indir {
/**
* struct ethtool_rxfh - command to get/set RX flow hash indir or/and hash key.
* @cmd: Specific command number - %ETHTOOL_GRSSH or %ETHTOOL_SRSSH
- * @rss_context: RSS context identifier.
+ * @rss_context: RSS context identifier. Context 0 is the default for normal
+ * traffic; other contexts can be referenced as the destination for RX flow
+ * classification rules. %ETH_RXFH_CONTEXT_ALLOC is used with command
+ * %ETHTOOL_SRSSH to allocate a new RSS context; on return this field will
+ * contain the ID of the newly allocated context.
* @indir_size: On entry, the array size of the user buffer for the
* indirection table, which may be zero, or (for %ETHTOOL_SRSSH),
* %ETH_RXFH_INDIR_NO_CHANGE. On return from %ETHTOOL_GRSSH,
@@ -1009,7 +1025,8 @@ struct ethtool_rxfh_indir {
* size should be returned. For %ETHTOOL_SRSSH, an @indir_size of
* %ETH_RXFH_INDIR_NO_CHANGE means that indir table setting is not requested
* and a @indir_size of zero means the indir table should be reset to default
- * values. An hfunc of zero means that hash function setting is not requested.
+ * values (if @rss_context == 0) or that the RSS context should be deleted.
+ * An hfunc of zero means that hash function setting is not requested.
*/
struct ethtool_rxfh {
__u32 cmd;
@@ -1021,6 +1038,7 @@ struct ethtool_rxfh {
__u32 rsvd32;
__u32 rss_config[0];
};
+#define ETH_RXFH_CONTEXT_ALLOC 0xffffffff
#define ETH_RXFH_INDIR_NO_CHANGE 0xffffffff
/**
@@ -1635,6 +1653,8 @@ static inline int ethtool_validate_duplex(__u8 duplex)
/* Flag to enable additional fields in struct ethtool_rx_flow_spec */
#define FLOW_EXT 0x80000000
#define FLOW_MAC_EXT 0x40000000
+/* Flag to enable RSS spreading of traffic matching rule (nfc only) */
+#define FLOW_RSS 0x20000000
/* L3-L4 network traffic flow hash options */
#define RXH_L2DA (1 << 1)
diff --git a/net/core/ethtool.c b/net/core/ethtool.c
index 3f89c76d5c24..157cd9efa4be 100644
--- a/net/core/ethtool.c
+++ b/net/core/ethtool.c
@@ -1022,6 +1022,15 @@ static noinline_for_stack int ethtool_get_rxnfc(struct
net_device *dev,
if (copy_from_user(&info, useraddr, info_size))
return -EFAULT;
+ /* If FLOW_RSS was requested then user-space must be using the
+ * new definition, as FLOW_RSS is newer.
+ */
+ if (cmd == ETHTOOL_GRXFH && info.flow_type & FLOW_RSS) {
+ info_size = sizeof(info);
+ if (copy_from_user(&info, useraddr, info_size))
+ return -EFAULT;
+ }
+
if (info.cmd == ETHTOOL_GRXCLSRLALL) {
if (info.rule_cnt > 0) {
if (info.rule_cnt <= KMALLOC_MAX_SIZE / sizeof(u32))
@@ -1251,9 +1260,11 @@ static noinline_for_stack int ethtool_get_rxfh(struct
net_device *dev,
user_key_size = rxfh.key_size;
/* Check that reserved fields are 0 for now */
- if (rxfh.rss_context || rxfh.rsvd8[0] || rxfh.rsvd8[1] ||
- rxfh.rsvd8[2] || rxfh.rsvd32)
+ if (rxfh.rsvd8[0] || rxfh.rsvd8[1] || rxfh.rsvd8[2] || rxfh.rsvd32)
return -EINVAL;
+ /* Most drivers don't handle rss_context, check it's 0 as well */
+ if (rxfh.rss_context && !ops->get_rxfh_context)
+ return -EOPNOTSUPP;
rxfh.indir_size = dev_indir_size;
rxfh.key_size = dev_key_size;
@@ -1276,7 +1287,12 @@ static noinline_for_stack int ethtool_get_rxfh(struct
net_device *dev,
if (user_key_size)
hkey = rss_config + indir_bytes;
- ret = dev->ethtool_ops->get_rxfh(dev, indir, hkey, &dev_hfunc);
+ if (rxfh.rss_context)
+ ret = dev->ethtool_ops->get_rxfh_context(dev, indir, hkey,
+ &dev_hfunc,
+ rxfh.rss_context);
+ else
+ ret = dev->ethtool_ops->get_rxfh(dev, indir, hkey, &dev_hfunc);
if (ret)
goto out;
@@ -1306,6 +1322,7 @@ static noinline_for_stack int ethtool_set_rxfh(struct
net_device *dev,
u8 *hkey = NULL;
u8 *rss_config;
u32 rss_cfg_offset = offsetof(struct ethtool_rxfh, rss_config[0]);
+ bool delete = false;
if (!ops->get_rxnfc || !ops->set_rxfh)
return -EOPNOTSUPP;
@@ -1319,9 +1336,11 @@ static noinline_for_stack int ethtool_set_rxfh(struct
net_device *dev,
return -EFAULT;
/* Check that reserved fields are 0 for now */
- if (rxfh.rss_context || rxfh.rsvd8[0] || rxfh.rsvd8[1] ||
- rxfh.rsvd8[2] || rxfh.rsvd32)
+ if (rxfh.rsvd8[0] || rxfh.rsvd8[1] || rxfh.rsvd8[2] || rxfh.rsvd32)
return -EINVAL;
+ /* Most drivers don't handle rss_context, check it's 0 as well */
+ if (rxfh.rss_context && !ops->set_rxfh_context)
+ return -EOPNOTSUPP;
/* If either indir, hash key or function is valid, proceed further.
* Must request at least one change: indir size, hash key or function.
@@ -1346,7 +1365,8 @@ static noinline_for_stack int ethtool_set_rxfh(struct
net_device *dev,
if (ret)
goto out;
- /* rxfh.indir_size == 0 means reset the indir table to default.
+ /* rxfh.indir_size == 0 means reset the indir table to default (master
+ * context) or delete the context (other RSS contexts).
* rxfh.indir_size == ETH_RXFH_INDIR_NO_CHANGE means leave it unchanged.
*/
if (rxfh.indir_size &&
@@ -1359,9 +1379,13 @@ static noinline_for_stack int ethtool_set_rxfh(struct
net_device *dev,
if (ret)
goto out;
} else if (rxfh.indir_size == 0) {
- indir = (u32 *)rss_config;
- for (i = 0; i < dev_indir_size; i++)
- indir[i] = ethtool_rxfh_indir_default(i, rx_rings.data);
+ if (rxfh.rss_context == 0) {
+ indir = (u32 *)rss_config;
+ for (i = 0; i < dev_indir_size; i++)
+ indir[i] = ethtool_rxfh_indir_default(i,
rx_rings.data);
+ } else {
+ delete = true;
+ }
}
if (rxfh.key_size) {
@@ -1374,15 +1398,25 @@ static noinline_for_stack int ethtool_set_rxfh(struct
net_device *dev,
}
}
- ret = ops->set_rxfh(dev, indir, hkey, rxfh.hfunc);
+ if (rxfh.rss_context)
+ ret = ops->set_rxfh_context(dev, indir, hkey, rxfh.hfunc,
+ &rxfh.rss_context, delete);
+ else
+ ret = ops->set_rxfh(dev, indir, hkey, rxfh.hfunc);
if (ret)
goto out;
- /* indicate whether rxfh was set to default */
- if (rxfh.indir_size == 0)
- dev->priv_flags &= ~IFF_RXFH_CONFIGURED;
- else if (rxfh.indir_size != ETH_RXFH_INDIR_NO_CHANGE)
- dev->priv_flags |= IFF_RXFH_CONFIGURED;
+ if (copy_to_user(useraddr + offsetof(struct ethtool_rxfh, rss_context),
+ &rxfh.rss_context, sizeof(rxfh.rss_context)))
+ ret = -EFAULT;
+
+ if (!rxfh.rss_context) {
+ /* indicate whether rxfh was set to default */
+ if (rxfh.indir_size == 0)
+ dev->priv_flags &= ~IFF_RXFH_CONFIGURED;
+ else if (rxfh.indir_size != ETH_RXFH_INDIR_NO_CHANGE)
+ dev->priv_flags |= IFF_RXFH_CONFIGURED;
+ }
out:
kfree(rss_config);
