[RFC,v3,10/11] tap: Report virtio-net hashing support on Linux

Commit Message

Akihiko Odaki Sept. 15, 2024, 1:23 a.m. UTC

This allows offloading virtio-net hashing to tap on Linux.

Signed-off-by: Akihiko Odaki <[e-mail]>
---
 net/tap-linux.h   |  1 +
 net/tap_int.h     |  1 +
 net/tap-bsd.c     |  5 +++++
 net/tap-linux.c   | 13 +++++++++++++
 net/tap-solaris.c |  5 +++++
 net/tap-stub.c    |  5 +++++
 net/tap.c         |  8 ++++++++
 7 files changed, 38 insertions(+)

Patch

diff --git a/net/tap-linux.h b/net/tap-linux.h
index 5fac64c24f99..c773609c799e 100644
--- a/net/tap-linux.h
+++ b/net/tap-linux.h
@@ -32,6 +32,7 @@ 
 #define TUNSETVNETLE _IOW('T', 220, int)
 #define TUNSETVNETBE _IOW('T', 222, int)
 #define TUNSETSTEERINGEBPF _IOR('T', 224, int)
+#define TUNGETVNETHASHCAP _IOR('T', 228, NetVnetHash)
 #define TUNSETVNETHASH _IOW('T', 229, NetVnetHash)
 
 #endif
diff --git a/net/tap_int.h b/net/tap_int.h
index e1b53e343397..84a88841b720 100644
--- a/net/tap_int.h
+++ b/net/tap_int.h
@@ -36,6 +36,7 @@  ssize_t tap_read_packet(int tapfd, uint8_t *buf, int maxlen);
 
 void tap_set_sndbuf(int fd, const NetdevTapOptions *tap, Error **errp);
 int tap_probe_vnet_hdr(int fd, Error **errp);
+bool tap_probe_vnet_hash_supported_types(int fd, uint32_t *types);
 int tap_probe_has_ufo(int fd);
 int tap_probe_has_uso(int fd);
 void tap_fd_set_offload(int fd, int csum, int tso4, int tso6, int ecn, int ufo,
diff --git a/net/tap-bsd.c b/net/tap-bsd.c
index 2eee0c0a0ec5..142e1abe0420 100644
--- a/net/tap-bsd.c
+++ b/net/tap-bsd.c
@@ -217,6 +217,11 @@  int tap_probe_has_uso(int fd)
     return 0;
 }
 
+bool tap_probe_vnet_hash_supported_types(int fd, uint32_t *types)
+{
+    return false;
+}
+
 void tap_fd_set_vnet_hdr_len(int fd, int len)
 {
 }
diff --git a/net/tap-linux.c b/net/tap-linux.c
index e96d38eec922..a601cb1ed2d9 100644
--- a/net/tap-linux.c
+++ b/net/tap-linux.c
@@ -185,6 +185,19 @@  int tap_probe_has_uso(int fd)
     return 1;
 }
 
+bool tap_probe_vnet_hash_supported_types(int fd, uint32_t *types)
+{
+    NetVnetHash hash;
+
+    if (ioctl(fd, TUNGETVNETHASHCAP, &hash)) {
+        return false;
+    }
+
+    *types = hash.types;
+
+    return true;
+}
+
 void tap_fd_set_vnet_hdr_len(int fd, int len)
 {
     if (ioctl(fd, TUNSETVNETHDRSZ, &len) == -1) {
diff --git a/net/tap-solaris.c b/net/tap-solaris.c
index c65104b84e93..00d1c850680d 100644
--- a/net/tap-solaris.c
+++ b/net/tap-solaris.c
@@ -221,6 +221,11 @@  int tap_probe_has_uso(int fd)
     return 0;
 }
 
+bool tap_probe_vnet_hash_supported_types(int fd, uint32_t *types)
+{
+    return false;
+}
+
 void tap_fd_set_vnet_hdr_len(int fd, int len)
 {
 }
diff --git a/net/tap-stub.c b/net/tap-stub.c
index 5bdc76216b7f..a4718654fbeb 100644
--- a/net/tap-stub.c
+++ b/net/tap-stub.c
@@ -52,6 +52,11 @@  int tap_probe_has_uso(int fd)
     return 0;
 }
 
+bool tap_probe_vnet_hash_supported_types(int fd, uint32_t *types)
+{
+    return false;
+}
+
 void tap_fd_set_vnet_hdr_len(int fd, int len)
 {
 }
diff --git a/net/tap.c b/net/tap.c
index 8d451c745d70..e17565c2ac3c 100644
--- a/net/tap.c
+++ b/net/tap.c
@@ -248,6 +248,13 @@  static void tap_set_vnet_hdr_len(NetClientState *nc, int len)
     s->using_vnet_hdr = true;
 }
 
+static bool tap_get_vnet_hash_supported_types(NetClientState *nc,
+                                              uint32_t *types)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+    return tap_probe_vnet_hash_supported_types(s->fd, types);
+}
+
 static void tap_set_vnet_hash(NetClientState *nc, const NetVnetHash *hash)
 {
     TAPState *s = DO_UPCAST(TAPState, nc, nc);
@@ -350,6 +357,7 @@  static NetClientInfo net_tap_info = {
     .has_vnet_hdr_len = tap_has_vnet_hdr_len,
     .set_offload = tap_set_offload,
     .set_vnet_hdr_len = tap_set_vnet_hdr_len,
+    .get_vnet_hash_supported_types = tap_get_vnet_hash_supported_types,
     .set_vnet_hash = tap_set_vnet_hash,
     .set_vnet_le = tap_set_vnet_le,
     .set_vnet_be = tap_set_vnet_be,