From: Wei Hu <weh@linux.microsoft.com>
To: longli@kernel.org, kotaranov@microsoft.com, kuba@kernel.org,
davem@davemloft.net, pabeni@redhat.com, edumazet@google.com,
andrew+netdev@lunn.ch, jgg@ziepe.ca, leon@kernel.org,
haiyangz@microsoft.com, wei.liu@kernel.org, decui@microsoft.com,
shradhagupta@linux.microsoft.com, horms@kernel.org,
ernis@linux.microsoft.com, stephen@networkplumber.org
Cc: netdev@vger.kernel.org, linux-rdma@vger.kernel.org,
linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org,
dipayanroy@linux.microsoft.com, bpf@vger.kernel.org,
sdf@fomichev.me, daniel@iogearbox.net, hawk@kernel.org,
ast@kernel.org, john.fastabend@gmail.com, weh@microsoft.com
Subject: [PATCH net-next v6 07/13] net: mana: swap queue sets in mana_change_mtu
Date: Fri, 9 Oct 2026 14:41:18 +0000 [thread overview]
Message-ID: <e9524a67c6e157f2e110f4e9f51ec3c94293a64d.1790795005.git.weh@linux.microsoft.com> (raw)
In-Reply-To: <cover.1790795005.git.weh@linux.microsoft.com>
From: Long Li <longli@microsoft.com>
Carry the MTU in the queue set and size replacement RX buffers from it.
Publish ndev->mtu after RSS configuration succeeds; allocation failure
leaves the live queues and advertised MTU unchanged.
This full rebuild temporarily keeps both sets of SQ/RQ/CQ objects,
RX buffers and page pools live. The port-owned EQ pool is shared,
not doubled. Device resource limits may reject this temporary peak;
allocation failure preserves the live queues and configuration.
Reserve RAW-QP admission under vport_mutex for the entire live
replacement, including unpublished queues, fail-close and scratch
cleanup. Preserve validation, no-op and down-port behavior.
Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Wei Hu <weh@microsoft.com>
---
drivers/net/ethernet/microsoft/mana/mana_en.c | 66 ++++++++++++++-----
.../ethernet/microsoft/mana/mana_ethtool.c | 10 +--
include/net/mana/mana.h | 7 +-
3 files changed, 60 insertions(+), 23 deletions(-)
diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
index 10225c09f5b7..4577a473ff42 100644
--- a/drivers/net/ethernet/microsoft/mana/mana_en.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
@@ -927,32 +927,52 @@ int mana_pre_alloc_rxbufs(struct mana_port_context *mpc, int new_mtu, int num_qu
static int mana_change_mtu(struct net_device *ndev, int new_mtu)
{
struct mana_port_context *mpc = netdev_priv(ndev);
- unsigned int old_mtu = ndev->mtu;
+ struct mana_port_context *scratch;
+ struct mana_qset newq, oldq;
int err;
- /* Pre-allocate buffers to prevent failure in mana_attach later */
- err = mana_pre_alloc_rxbufs(mpc, new_mtu, mpc->num_queues);
- if (err) {
- netdev_err(ndev, "Insufficient memory for new MTU\n");
- return err;
+ if (!mpc->port_is_up) {
+ mpc->configured_mtu = new_mtu;
+ WRITE_ONCE(ndev->mtu, new_mtu);
+ return 0;
}
- err = mana_detach(ndev, false);
- if (err) {
- netdev_err(ndev, "mana_detach failed: %d\n", err);
- goto out;
+ /* Fail-close may release the Ethernet vport reference. */
+ mutex_lock(&mpc->vport_mutex);
+ if (mpc->channel_changing) {
+ mutex_unlock(&mpc->vport_mutex);
+ return -EBUSY;
+ }
+ mpc->channel_changing = true;
+ mutex_unlock(&mpc->vport_mutex);
+
+ scratch = mana_qset_scratch_alloc(mpc);
+ if (!scratch) {
+ err = -ENOMEM;
+ goto clear_flag;
}
- WRITE_ONCE(ndev->mtu, new_mtu);
+ err = mana_alloc_qset(mpc, scratch, mpc->num_queues,
+ mpc->rx_queue_size, mpc->tx_queue_size,
+ mpc->priv_flags, new_mtu, &newq);
+ if (err)
+ goto free_scratch;
- err = mana_attach(ndev);
+ err = mana_publish_qset(mpc, &newq, &oldq);
if (err) {
- netdev_err(ndev, "mana_attach failed: %d\n", err);
- WRITE_ONCE(ndev->mtu, old_mtu);
+ mana_free_qset(scratch, &newq);
+ goto free_scratch;
}
-out:
- mana_pre_dealloc_rxbufs(mpc);
+ mana_free_qset(scratch, &oldq);
+
+free_scratch:
+ mana_publish_close_if_needed(mpc);
+ mana_qset_scratch_free(scratch);
+clear_flag:
+ mutex_lock(&mpc->vport_mutex);
+ mpc->channel_changing = false;
+ mutex_unlock(&mpc->vport_mutex);
return err;
}
@@ -3306,7 +3326,8 @@ static struct mana_rxq *mana_create_rxq(struct mana_port_context *apc,
rxq->rxq_idx = rxq_idx;
rxq->rxobj = INVALID_MANA_HANDLE;
- mana_get_rxbuf_cfg(apc, ndev->mtu, &rxq->datasize, &rxq->alloc_size,
+ mana_get_rxbuf_cfg(apc, apc->configured_mtu, &rxq->datasize,
+ &rxq->alloc_size,
&rxq->headroom, &rxq->frag_count);
/* Create page pool for RX queue */
err = mana_create_page_pool(rxq, gc);
@@ -4017,6 +4038,7 @@ static void mana_qset_snapshot(const struct mana_port_context *ctx,
out->rx_queue_size = ctx->rx_queue_size;
out->tx_queue_size = ctx->tx_queue_size;
out->priv_flags = ctx->priv_flags;
+ out->mtu = ctx->configured_mtu;
}
/* Vport identity and port debugfs outlive queue sets. */
@@ -4033,6 +4055,7 @@ static void mana_qset_install(struct mana_port_context *ctx,
ctx->rx_queue_size = qset->rx_queue_size;
ctx->tx_queue_size = qset->tx_queue_size;
ctx->priv_flags = qset->priv_flags;
+ ctx->configured_mtu = qset->mtu;
}
/* Scratch starts without SQs/RQs and borrows the port's EQ pool. Never call
@@ -4073,7 +4096,7 @@ void mana_qset_scratch_free(struct mana_port_context *scratch)
int mana_alloc_qset(struct mana_port_context *apc,
struct mana_port_context *scratch, unsigned int num_queues,
unsigned int rx_queue_size, unsigned int tx_queue_size,
- u32 priv_flags, struct mana_qset *out)
+ u32 priv_flags, int mtu, struct mana_qset *out)
{
struct net_device *ndev = scratch->ndev;
int err;
@@ -4085,6 +4108,8 @@ int mana_alloc_qset(struct mana_port_context *apc,
scratch->tx_queue_size = tx_queue_size;
scratch->priv_flags = priv_flags;
+ scratch->configured_mtu = mtu;
+
err = mana_init_port_context(scratch);
if (err)
goto out_err;
@@ -4337,6 +4362,8 @@ int mana_publish_qset(struct mana_port_context *apc, struct mana_qset *newq,
if (err)
goto rollback;
+ WRITE_ONCE(ndev->mtu, apc->configured_mtu);
+
/* Publish fields before opening the gate; pair with TX/XDP read
* barriers. The post-gate full barrier cannot replace this.
*/
@@ -4392,6 +4419,8 @@ int mana_publish_qset(struct mana_port_context *apc, struct mana_qset *newq,
synchronize_net();
mana_fold_qset_rx_stats(apc, out_old);
+ WRITE_ONCE(ndev->mtu, apc->configured_mtu);
+
/* Publish restored fields before reopening the gate, as on success. */
smp_wmb();
@@ -4544,6 +4573,7 @@ static int mana_probe_port(struct mana_context *ac, int port_idx,
apc->port_handle = INVALID_MANA_HANDLE;
apc->pf_filter_handle = INVALID_MANA_HANDLE;
apc->port_idx = port_idx;
+ apc->configured_mtu = ndev->mtu;
apc->link_cfg_error = 1;
apc->cqe_coalescing_enable = 0;
apc->cqe8_coalescing_enable = 0;
diff --git a/drivers/net/ethernet/microsoft/mana/mana_ethtool.c b/drivers/net/ethernet/microsoft/mana/mana_ethtool.c
index 7a1120342208..2ad0fb4d5008 100644
--- a/drivers/net/ethernet/microsoft/mana/mana_ethtool.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_ethtool.c
@@ -738,7 +738,8 @@ static int mana_set_channels(struct net_device *ndev,
}
err = mana_alloc_qset(apc, scratch, new_count, apc->rx_queue_size,
- apc->tx_queue_size, apc->priv_flags, &newq);
+ apc->tx_queue_size, apc->priv_flags,
+ apc->configured_mtu, &newq);
if (err)
goto free_scratch;
@@ -827,7 +828,7 @@ static int mana_set_ringparam(struct net_device *ndev,
}
err = mana_alloc_qset(apc, scratch, apc->num_queues, new_rx, new_tx,
- apc->priv_flags, &newq);
+ apc->priv_flags, apc->configured_mtu, &newq);
if (err) {
NL_SET_ERR_MSG_FMT(extack, "failed to change ring params: %d",
err);
@@ -917,8 +918,9 @@ static int mana_set_priv_flags(struct net_device *ndev, u32 priv_flags)
goto clear_flag;
}
- err = mana_alloc_qset(apc, scratch, apc->num_queues, apc->rx_queue_size,
- apc->tx_queue_size, priv_flags, &newq);
+ err = mana_alloc_qset(apc, scratch, apc->num_queues,
+ apc->rx_queue_size, apc->tx_queue_size,
+ priv_flags, apc->configured_mtu, &newq);
if (err)
goto free_scratch;
diff --git a/include/net/mana/mana.h b/include/net/mana/mana.h
index c66f9dcab407..3faad257e97e 100644
--- a/include/net/mana/mana.h
+++ b/include/net/mana/mana.h
@@ -626,6 +626,10 @@ struct mana_port_context {
unsigned int rx_queue_size;
unsigned int tx_queue_size;
+ /* MTU used to size RX buffers, independent of ndev->mtu during a swap.
+ */
+ int configured_mtu;
+
mana_handle_t port_handle;
mana_handle_t pf_filter_handle;
@@ -702,6 +706,7 @@ struct mana_qset {
unsigned int tx_queue_size;
u32 priv_flags;
+ int mtu;
};
netdev_tx_t mana_start_xmit(struct sk_buff *skb, struct net_device *ndev);
@@ -724,7 +729,7 @@ static inline struct mana_stats_rx *mana_rxq_stats(struct mana_rxq *rxq)
int mana_alloc_qset(struct mana_port_context *apc,
struct mana_port_context *scratch, unsigned int num_queues,
unsigned int rx_queue_size, unsigned int tx_queue_size,
- u32 priv_flags, struct mana_qset *out);
+ u32 priv_flags, int mtu, struct mana_qset *out);
int mana_publish_qset(struct mana_port_context *apc, struct mana_qset *newq,
struct mana_qset *out_old);
void mana_publish_close_if_needed(struct mana_port_context *apc);
next prev parent reply other threads:[~2026-10-09 14:41 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-09 14:41 [PATCH net-next v6 00/13] net: mana: reconfigure by replacing the queue set Wei Hu
2026-10-09 14:41 ` [PATCH net-next v6 01/13] net: mana: add queue-set allocation and teardown helpers Wei Hu
2026-10-09 14:41 ` [PATCH net-next v6 02/13] net: mana: share the EQ pool across a queue-set swap Wei Hu
2026-10-09 14:41 ` [PATCH net-next v6 03/13] net: mana: keep per-queue statistics in the port context Wei Hu
2026-10-09 14:41 ` [PATCH net-next v6 04/13] net: mana: swap queue sets in mana_set_channels Wei Hu
2026-10-09 14:41 ` [PATCH net-next v6 05/13] net: mana: swap queue sets in mana_set_ringparam Wei Hu
2026-10-09 14:41 ` [PATCH net-next v6 06/13] net: mana: swap queue sets in mana_set_priv_flags Wei Hu
2026-10-09 14:41 ` Wei Hu [this message]
2026-10-09 14:41 ` [PATCH net-next v6 08/13] net: mana: swap queue sets in mana_xdp_set Wei Hu
2026-10-09 14:41 ` [PATCH net-next v6 09/13] net: mana: do not bail out of mana_detach on dealloc failure Wei Hu
2026-10-09 14:41 ` [PATCH net-next v6 10/13] net: mana: release EQs left idle by a channel-count reduction Wei Hu
2026-10-09 14:41 ` [PATCH net-next v6 11/13] net: mana: keep a user-configured RSS table across a queue rebuild Wei Hu
2026-10-09 14:41 ` [PATCH net-next v6 12/13] net: mana: keep the surviving queues when the channel count is reduced Wei Hu
2026-10-09 14:41 ` [PATCH net-next v6 13/13] net: mana: keep the existing queues when the channel count is raised Wei Hu
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