Merge tag 'net-pull-request' of https://github.com/jasowang/qemu into staging

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# gpg: Signature made Tue 04 Jun 2024 02:30:22 AM CDT
# gpg:                using RSA key 215D46F48246689EC77F3562EF04965B398D6211
# gpg: Good signature from "Jason Wang (Jason Wang on RedHat) <jasowang@redhat.com>" [undefined]
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 215D 46F4 8246 689E C77F  3562 EF04 965B 398D 6211

* tag 'net-pull-request' of https://github.com/jasowang/qemu:
  ebpf: Added traces back. Changed source set for eBPF to 'system'.
  virtio-net: drop too short packets early
  ebpf: Add a separate target for skeleton
  ebpf: Refactor tun_rss_steering_prog()
  ebpf: Return 0 when configuration fails
  ebpf: Fix RSS error handling
  virtio-net: Do not write hashes to peer buffer
  virtio-net: Always set populate_hash
  virtio-net: Unify the logic to update NIC state for RSS
  virtio-net: Disable RSS on reset
  virtio-net: Shrink header byte swapping buffer
  virtio-net: Copy header only when necessary
  virtio-net: Add only one queue pair when realizing
  virtio-net: Do not propagate ebpf-rss-fds errors
  tap: Shrink zeroed virtio-net header
  tap: Call tap_receive_iov() from tap_receive()
  net: Remove receive_raw()
  net: Move virtio-net header length assertion
  tap: Remove qemu_using_vnet_hdr()
  tap: Remove tap_probe_vnet_hdr_len()

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

1 files changed, 21 insertions, 23 deletions

diff --git a/tools/ebpf/rss.bpf.c b/tools/ebpf/rss.bpf.c
index 9715d1170e..c989cb3cd8 100644
--- a/tools/ebpf/rss.bpf.c
+++ b/tools/ebpf/rss.bpf.c
@@ -380,18 +380,19 @@ error:
     return err;
 }
 
-static inline __u32 calculate_rss_hash(struct __sk_buff *skb,
-        struct rss_config_t *config, struct toeplitz_key_data_t *toe)
+static inline bool calculate_rss_hash(struct __sk_buff *skb,
+                                      struct rss_config_t *config,
+                                      struct toeplitz_key_data_t *toe,
+                                      __u32 *result)
 {
     __u8 rss_input[HASH_CALCULATION_BUFFER_SIZE] = {};
     size_t bytes_written = 0;
-    __u32 result = 0;
     int err = 0;
     struct packet_hash_info_t packet_info = {};
 
     err = parse_packet(skb, &packet_info);
     if (err) {
-        return 0;
+        return false;
     }
 
     if (packet_info.is_ipv4) {
@@ -524,11 +525,13 @@ static inline __u32 calculate_rss_hash(struct __sk_buff *skb,
         }
     }
 
-    if (bytes_written) {
-        net_toeplitz_add(&result, rss_input, bytes_written, toe);
+    if (!bytes_written) {
+        return false;
     }
 
-    return result;
+    net_toeplitz_add(result, rss_input, bytes_written, toe);
+
+    return true;
 }
 
 SEC("socket")
@@ -544,28 +547,23 @@ int tun_rss_steering_prog(struct __sk_buff *skb)
     config = bpf_map_lookup_elem(&tap_rss_map_configurations, &key);
     toe = bpf_map_lookup_elem(&tap_rss_map_toeplitz_key, &key);
 
-    if (config && toe) {
-        if (!config->redirect) {
-            return config->default_queue;
-        }
+    if (!config || !toe) {
+        return 0;
+    }
 
-        hash = calculate_rss_hash(skb, config, toe);
-        if (hash) {
-            __u32 table_idx = hash % config->indirections_len;
-            __u16 *queue = 0;
+    if (config->redirect && calculate_rss_hash(skb, config, toe, &hash)) {
+        __u32 table_idx = hash % config->indirections_len;
+        __u16 *queue = 0;
 
-            queue = bpf_map_lookup_elem(&tap_rss_map_indirection_table,
-                                        &table_idx);
+        queue = bpf_map_lookup_elem(&tap_rss_map_indirection_table,
+                                    &table_idx);
 
-            if (queue) {
-                return *queue;
-            }
+        if (queue) {
+            return *queue;
         }
-
-        return config->default_queue;
     }
 
-    return -1;
+    return config->default_queue;
 }
 
 char _license[] SEC("license") = "GPL v2";