| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <20250618205613.1432007-3-hramamurthy@google.com>
Date: Wed, 18 Jun 2025 20:56:12 +0000
From: Harshitha Ramamurthy <hramamurthy@...gle.com>
To: netdev@...r.kernel.org
Cc: jeroendb@...gle.com, hramamurthy@...gle.com, andrew+netdev@...n.ch,
davem@...emloft.net, edumazet@...gle.com, kuba@...nel.org, pabeni@...hat.com,
ast@...nel.org, daniel@...earbox.net, hawk@...nel.org,
john.fastabend@...il.com, sdf@...ichev.me, willemb@...gle.com,
ziweixiao@...gle.com, pkaligineedi@...gle.com, joshwash@...gle.com,
linux-kernel@...r.kernel.org, bpf@...r.kernel.org
Subject: [PATCH net-next 2/3] gve: refactor DQO TX methods to be more generic
for XDP
From: Joshua Washington <joshwash@...gle.com>
This patch performs various minor DQO TX datapath refactors in
preparation for adding XDP_TX and XDP_REDIRECT support. The following
refactors are performed:
1) gve_tx_fill_pkt_desc_dqo() relies on a SKB pointer to
get whether checksum offloading should be enabled. This won't work
for the XDP case, which does not have a SKB. This patch updates the
method to use a boolean representing whether checksum offloading
should be enabled directly.
2) gve_maybe_stop_dqo() contains some synchronization between the true
TX head and the cached value, a synchronization which is common for
XDP queues and normal netdev queues. However, that method is reserved
for netdev TX queues. To avoid duplicate code, this logic is factored
out into a new method, gve_has_tx_slots_available().
3) gve_tx_update_tail() is added to update the TX tail, a functionality
that will be common between normal TX and XDP TX codepaths.
Reviewed-by: Willem de Bruijn <willemb@...gle.com>
Signed-off-by: Joshua Washington <joshwash@...gle.com>
Signed-off-by: Praveen Kaligineedi <pkaligineedi@...gle.com>
Signed-off-by: Harshitha Ramamurthy <hramamurthy@...gle.com>
---
drivers/net/ethernet/google/gve/gve_tx_dqo.c | 85 +++++++++++---------
1 file changed, 47 insertions(+), 38 deletions(-)
diff --git a/drivers/net/ethernet/google/gve/gve_tx_dqo.c b/drivers/net/ethernet/google/gve/gve_tx_dqo.c
index 9d705d94b065..ba6b5cdaa922 100644
--- a/drivers/net/ethernet/google/gve/gve_tx_dqo.c
+++ b/drivers/net/ethernet/google/gve/gve_tx_dqo.c
@@ -439,12 +439,28 @@ static u32 num_avail_tx_slots(const struct gve_tx_ring *tx)
return tx->mask - num_used;
}
+/* Checks if the requested number of slots are available in the ring */
+static bool gve_has_tx_slots_available(struct gve_tx_ring *tx, u32 slots_req)
+{
+ u32 num_avail = num_avail_tx_slots(tx);
+
+ slots_req += GVE_TX_MIN_DESC_PREVENT_CACHE_OVERLAP;
+
+ if (num_avail >= slots_req)
+ return true;
+
+ /* Update cached TX head pointer */
+ tx->dqo_tx.head = atomic_read_acquire(&tx->dqo_compl.hw_tx_head);
+
+ return num_avail_tx_slots(tx) >= slots_req;
+}
+
static bool gve_has_avail_slots_tx_dqo(struct gve_tx_ring *tx,
int desc_count, int buf_count)
{
return gve_has_pending_packet(tx) &&
- num_avail_tx_slots(tx) >= desc_count &&
- gve_has_free_tx_qpl_bufs(tx, buf_count);
+ gve_has_tx_slots_available(tx, desc_count) &&
+ gve_has_free_tx_qpl_bufs(tx, buf_count);
}
/* Stops the queue if available descriptors is less than 'count'.
@@ -453,12 +469,6 @@ static bool gve_has_avail_slots_tx_dqo(struct gve_tx_ring *tx,
static int gve_maybe_stop_tx_dqo(struct gve_tx_ring *tx,
int desc_count, int buf_count)
{
- if (likely(gve_has_avail_slots_tx_dqo(tx, desc_count, buf_count)))
- return 0;
-
- /* Update cached TX head pointer */
- tx->dqo_tx.head = atomic_read_acquire(&tx->dqo_compl.hw_tx_head);
-
if (likely(gve_has_avail_slots_tx_dqo(tx, desc_count, buf_count)))
return 0;
@@ -472,8 +482,6 @@ static int gve_maybe_stop_tx_dqo(struct gve_tx_ring *tx,
/* After stopping queue, check if we can transmit again in order to
* avoid TOCTOU bug.
*/
- tx->dqo_tx.head = atomic_read_acquire(&tx->dqo_compl.hw_tx_head);
-
if (likely(!gve_has_avail_slots_tx_dqo(tx, desc_count, buf_count)))
return -EBUSY;
@@ -500,11 +508,9 @@ static void gve_extract_tx_metadata_dqo(const struct sk_buff *skb,
}
static void gve_tx_fill_pkt_desc_dqo(struct gve_tx_ring *tx, u32 *desc_idx,
- struct sk_buff *skb, u32 len, u64 addr,
+ bool enable_csum, u32 len, u64 addr,
s16 compl_tag, bool eop, bool is_gso)
{
- const bool checksum_offload_en = skb->ip_summed == CHECKSUM_PARTIAL;
-
while (len > 0) {
struct gve_tx_pkt_desc_dqo *desc =
&tx->dqo.tx_ring[*desc_idx].pkt;
@@ -515,7 +521,7 @@ static void gve_tx_fill_pkt_desc_dqo(struct gve_tx_ring *tx, u32 *desc_idx,
.buf_addr = cpu_to_le64(addr),
.dtype = GVE_TX_PKT_DESC_DTYPE_DQO,
.end_of_packet = cur_eop,
- .checksum_offload_enable = checksum_offload_en,
+ .checksum_offload_enable = enable_csum,
.compl_tag = cpu_to_le16(compl_tag),
.buf_size = cur_len,
};
@@ -612,6 +618,25 @@ gve_tx_fill_general_ctx_desc(struct gve_tx_general_context_desc_dqo *desc,
};
}
+static void gve_tx_update_tail(struct gve_tx_ring *tx, u32 desc_idx)
+{
+ u32 last_desc_idx = (desc_idx - 1) & tx->mask;
+ u32 last_report_event_interval =
+ (last_desc_idx - tx->dqo_tx.last_re_idx) & tx->mask;
+
+ /* Commit the changes to our state */
+ tx->dqo_tx.tail = desc_idx;
+
+ /* Request a descriptor completion on the last descriptor of the
+ * packet if we are allowed to by the HW enforced interval.
+ */
+
+ if (unlikely(last_report_event_interval >= GVE_TX_MIN_RE_INTERVAL)) {
+ tx->dqo.tx_ring[last_desc_idx].pkt.report_event = true;
+ tx->dqo_tx.last_re_idx = last_desc_idx;
+ }
+}
+
static int gve_tx_add_skb_no_copy_dqo(struct gve_tx_ring *tx,
struct sk_buff *skb,
struct gve_tx_pending_packet_dqo *pkt,
@@ -619,6 +644,7 @@ static int gve_tx_add_skb_no_copy_dqo(struct gve_tx_ring *tx,
u32 *desc_idx,
bool is_gso)
{
+ bool enable_csum = skb->ip_summed == CHECKSUM_PARTIAL;
const struct skb_shared_info *shinfo = skb_shinfo(skb);
int i;
@@ -644,7 +670,7 @@ static int gve_tx_add_skb_no_copy_dqo(struct gve_tx_ring *tx,
dma_unmap_addr_set(pkt, dma[pkt->num_bufs], addr);
++pkt->num_bufs;
- gve_tx_fill_pkt_desc_dqo(tx, desc_idx, skb, len, addr,
+ gve_tx_fill_pkt_desc_dqo(tx, desc_idx, enable_csum, len, addr,
completion_tag,
/*eop=*/shinfo->nr_frags == 0, is_gso);
}
@@ -664,7 +690,7 @@ static int gve_tx_add_skb_no_copy_dqo(struct gve_tx_ring *tx,
dma[pkt->num_bufs], addr);
++pkt->num_bufs;
- gve_tx_fill_pkt_desc_dqo(tx, desc_idx, skb, len, addr,
+ gve_tx_fill_pkt_desc_dqo(tx, desc_idx, enable_csum, len, addr,
completion_tag, is_eop, is_gso);
}
@@ -709,6 +735,7 @@ static int gve_tx_add_skb_copy_dqo(struct gve_tx_ring *tx,
u32 *desc_idx,
bool is_gso)
{
+ bool enable_csum = skb->ip_summed == CHECKSUM_PARTIAL;
u32 copy_offset = 0;
dma_addr_t dma_addr;
u32 copy_len;
@@ -730,7 +757,7 @@ static int gve_tx_add_skb_copy_dqo(struct gve_tx_ring *tx,
copy_offset += copy_len;
dma_sync_single_for_device(tx->dev, dma_addr,
copy_len, DMA_TO_DEVICE);
- gve_tx_fill_pkt_desc_dqo(tx, desc_idx, skb,
+ gve_tx_fill_pkt_desc_dqo(tx, desc_idx, enable_csum,
copy_len,
dma_addr,
completion_tag,
@@ -800,24 +827,7 @@ static int gve_tx_add_skb_dqo(struct gve_tx_ring *tx,
tx->dqo_tx.posted_packet_desc_cnt += pkt->num_bufs;
- /* Commit the changes to our state */
- tx->dqo_tx.tail = desc_idx;
-
- /* Request a descriptor completion on the last descriptor of the
- * packet if we are allowed to by the HW enforced interval.
- */
- {
- u32 last_desc_idx = (desc_idx - 1) & tx->mask;
- u32 last_report_event_interval =
- (last_desc_idx - tx->dqo_tx.last_re_idx) & tx->mask;
-
- if (unlikely(last_report_event_interval >=
- GVE_TX_MIN_RE_INTERVAL)) {
- tx->dqo.tx_ring[last_desc_idx].pkt.report_event = true;
- tx->dqo_tx.last_re_idx = last_desc_idx;
- }
- }
-
+ gve_tx_update_tail(tx, desc_idx);
return 0;
err:
@@ -951,9 +961,8 @@ static int gve_try_tx_skb(struct gve_priv *priv, struct gve_tx_ring *tx,
/* Metadata + (optional TSO) + data descriptors. */
total_num_descs = 1 + skb_is_gso(skb) + num_buffer_descs;
- if (unlikely(gve_maybe_stop_tx_dqo(tx, total_num_descs +
- GVE_TX_MIN_DESC_PREVENT_CACHE_OVERLAP,
- num_buffer_descs))) {
+ if (unlikely(gve_maybe_stop_tx_dqo(tx, total_num_descs,
+ num_buffer_descs))) {
return -1;
}
--
2.50.0.rc2.761.g2dc52ea45b-goog
Powered by blists - more mailing lists