[PATCH V2,net-next, 0/3] net: mana: Add support for jumbo frame

[PATCH V2,net-next, 0/3] net: mana: Add support for jumbo frame

[Haiyang Zhang]

The set adds support for jumbo frame,
with some optimization for the RX path.

Haiyang Zhang (3):
  net: mana: Use napi_build_skb in RX path
  net: mana: Enable RX path to handle various MTU sizes
  net: mana: Add support for jumbo frame

 .../net/ethernet/microsoft/mana/mana_bpf.c    |  22 +-
 drivers/net/ethernet/microsoft/mana/mana_en.c | 383 ++++++++++++++----
 include/net/mana/gdma.h                       |   4 +
 include/net/mana/mana.h                       |  27 +-
 4 files changed, 346 insertions(+), 90 deletions(-)

-- 
2.25.1

[PATCH V2,net-next, 1/3] net: mana: Use napi_build_skb in RX path

[Haiyang Zhang]

Use napi_build_skb() instead of build_skb() to take advantage of the
NAPI percpu caches to obtain skbuff_head.

Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
---
 drivers/net/ethernet/microsoft/mana/mana_en.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
index 492474b4d8aa..112c642dc89b 100644
--- a/drivers/net/ethernet/microsoft/mana/mana_en.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
@@ -1188,7 +1188,7 @@ static void mana_post_pkt_rxq(struct mana_rxq *rxq)
 static struct sk_buff *mana_build_skb(void *buf_va, uint pkt_len,
 				      struct xdp_buff *xdp)
 {
-	struct sk_buff *skb = build_skb(buf_va, PAGE_SIZE);
+	struct sk_buff *skb = napi_build_skb(buf_va, PAGE_SIZE);
 
 	if (!skb)
 		return NULL;
-- 
2.25.1

Re: [PATCH V2,net-next, 1/3] net: mana: Use napi_build_skb in RX path

[Jesse Brandeburg]

On 4/7/2023 1:59 PM, Haiyang Zhang wrote:
> Use napi_build_skb() instead of build_skb() to take advantage of the
> NAPI percpu caches to obtain skbuff_head.
> 
> Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>

Reviewed-by: Jesse Brandeburg <jesse.brandeburg@intel.com>

[PATCH V2,net-next, 2/3] net: mana: Enable RX path to handle various MTU sizes

[Haiyang Zhang]

Update RX data path to allocate and use RX queue DMA buffers with
proper size based on potentially various MTU sizes.

Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>

---
V2:
Refectored to multiple patches for readability. Suggested by Yunsheng Lin.

---
 drivers/net/ethernet/microsoft/mana/mana_en.c | 188 +++++++++++-------
 include/net/mana/mana.h                       |  13 +-
 2 files changed, 124 insertions(+), 77 deletions(-)

diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
index 112c642dc89b..e5d5dea763f2 100644
--- a/drivers/net/ethernet/microsoft/mana/mana_en.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
@@ -1185,10 +1185,10 @@ static void mana_post_pkt_rxq(struct mana_rxq *rxq)
 	WARN_ON_ONCE(recv_buf_oob->wqe_inf.wqe_size_in_bu != 1);
 }
 
-static struct sk_buff *mana_build_skb(void *buf_va, uint pkt_len,
-				      struct xdp_buff *xdp)
+static struct sk_buff *mana_build_skb(struct mana_rxq *rxq, void *buf_va,
+				      uint pkt_len, struct xdp_buff *xdp)
 {
-	struct sk_buff *skb = napi_build_skb(buf_va, PAGE_SIZE);
+	struct sk_buff *skb = napi_build_skb(buf_va, rxq->alloc_size);
 
 	if (!skb)
 		return NULL;
@@ -1196,11 +1196,12 @@ static struct sk_buff *mana_build_skb(void *buf_va, uint pkt_len,
 	if (xdp->data_hard_start) {
 		skb_reserve(skb, xdp->data - xdp->data_hard_start);
 		skb_put(skb, xdp->data_end - xdp->data);
-	} else {
-		skb_reserve(skb, XDP_PACKET_HEADROOM);
-		skb_put(skb, pkt_len);
+		return skb;
 	}
 
+	skb_reserve(skb, rxq->headroom);
+	skb_put(skb, pkt_len);
+
 	return skb;
 }
 
@@ -1233,7 +1234,7 @@ static void mana_rx_skb(void *buf_va, struct mana_rxcomp_oob *cqe,
 	if (act != XDP_PASS && act != XDP_TX)
 		goto drop_xdp;
 
-	skb = mana_build_skb(buf_va, pkt_len, &xdp);
+	skb = mana_build_skb(rxq, buf_va, pkt_len, &xdp);
 
 	if (!skb)
 		goto drop;
@@ -1282,14 +1283,72 @@ static void mana_rx_skb(void *buf_va, struct mana_rxcomp_oob *cqe,
 	u64_stats_update_end(&rx_stats->syncp);
 
 drop:
-	WARN_ON_ONCE(rxq->xdp_save_page);
-	rxq->xdp_save_page = virt_to_page(buf_va);
+	WARN_ON_ONCE(rxq->xdp_save_va);
+	/* Save for reuse */
+	rxq->xdp_save_va = buf_va;
 
 	++ndev->stats.rx_dropped;
 
 	return;
 }
 
+static void *mana_get_rxfrag(struct mana_rxq *rxq, struct device *dev,
+			     dma_addr_t *da, bool is_napi)
+{
+	struct page *page;
+	void *va;
+
+	/* Reuse XDP dropped page if available */
+	if (rxq->xdp_save_va) {
+		va = rxq->xdp_save_va;
+		rxq->xdp_save_va = NULL;
+	} else if (rxq->alloc_size > PAGE_SIZE) {
+		if (is_napi)
+			va = napi_alloc_frag(rxq->alloc_size);
+		else
+			va = netdev_alloc_frag(rxq->alloc_size);
+
+		if (!va)
+			return NULL;
+	} else {
+		page = dev_alloc_page();
+		if (!page)
+			return NULL;
+
+		va = page_to_virt(page);
+	}
+
+	*da = dma_map_single(dev, va + rxq->headroom, rxq->datasize,
+			     DMA_FROM_DEVICE);
+
+	if (dma_mapping_error(dev, *da)) {
+		put_page(virt_to_head_page(va));
+		return NULL;
+	}
+
+	return va;
+}
+
+/* Allocate frag for rx buffer, and save the old buf */
+static void mana_refill_rxoob(struct device *dev, struct mana_rxq *rxq,
+			      struct mana_recv_buf_oob *rxoob, void **old_buf)
+{
+	dma_addr_t da;
+	void *va;
+
+	va = mana_get_rxfrag(rxq, dev, &da, true);
+
+	if (!va)
+		return;
+
+	dma_unmap_single(dev, rxoob->sgl[0].address, rxq->datasize,
+			 DMA_FROM_DEVICE);
+	*old_buf = rxoob->buf_va;
+
+	rxoob->buf_va = va;
+	rxoob->sgl[0].address = da;
+}
+
 static void mana_process_rx_cqe(struct mana_rxq *rxq, struct mana_cq *cq,
 				struct gdma_comp *cqe)
 {
@@ -1299,10 +1358,8 @@ static void mana_process_rx_cqe(struct mana_rxq *rxq, struct mana_cq *cq,
 	struct mana_recv_buf_oob *rxbuf_oob;
 	struct mana_port_context *apc;
 	struct device *dev = gc->dev;
-	void *new_buf, *old_buf;
-	struct page *new_page;
+	void *old_buf = NULL;
 	u32 curr, pktlen;
-	dma_addr_t da;
 
 	apc = netdev_priv(ndev);
 
@@ -1345,40 +1402,11 @@ static void mana_process_rx_cqe(struct mana_rxq *rxq, struct mana_cq *cq,
 	rxbuf_oob = &rxq->rx_oobs[curr];
 	WARN_ON_ONCE(rxbuf_oob->wqe_inf.wqe_size_in_bu != 1);
 
-	/* Reuse XDP dropped page if available */
-	if (rxq->xdp_save_page) {
-		new_page = rxq->xdp_save_page;
-		rxq->xdp_save_page = NULL;
-	} else {
-		new_page = alloc_page(GFP_ATOMIC);
-	}
-
-	if (new_page) {
-		da = dma_map_page(dev, new_page, XDP_PACKET_HEADROOM, rxq->datasize,
-				  DMA_FROM_DEVICE);
-
-		if (dma_mapping_error(dev, da)) {
-			__free_page(new_page);
-			new_page = NULL;
-		}
-	}
-
-	new_buf = new_page ? page_to_virt(new_page) : NULL;
-
-	if (new_buf) {
-		dma_unmap_page(dev, rxbuf_oob->buf_dma_addr, rxq->datasize,
-			       DMA_FROM_DEVICE);
-
-		old_buf = rxbuf_oob->buf_va;
-
-		/* refresh the rxbuf_oob with the new page */
-		rxbuf_oob->buf_va = new_buf;
-		rxbuf_oob->buf_dma_addr = da;
-		rxbuf_oob->sgl[0].address = rxbuf_oob->buf_dma_addr;
-	} else {
-		old_buf = NULL; /* drop the packet if no memory */
-	}
+	mana_refill_rxoob(dev, rxq, rxbuf_oob, &old_buf);
 
+	/* Unsuccessful refill will have old_buf == NULL.
+	 * In this case, mana_rx_skb() will drop the packet.
+	 */
 	mana_rx_skb(old_buf, oob, rxq);
 
 drop:
@@ -1659,8 +1687,8 @@ static void mana_destroy_rxq(struct mana_port_context *apc,
 
 	mana_deinit_cq(apc, &rxq->rx_cq);
 
-	if (rxq->xdp_save_page)
-		__free_page(rxq->xdp_save_page);
+	if (rxq->xdp_save_va)
+		put_page(virt_to_head_page(rxq->xdp_save_va));
 
 	for (i = 0; i < rxq->num_rx_buf; i++) {
 		rx_oob = &rxq->rx_oobs[i];
@@ -1668,10 +1696,10 @@ static void mana_destroy_rxq(struct mana_port_context *apc,
 		if (!rx_oob->buf_va)
 			continue;
 
-		dma_unmap_page(dev, rx_oob->buf_dma_addr, rxq->datasize,
-			       DMA_FROM_DEVICE);
+		dma_unmap_single(dev, rx_oob->sgl[0].address,
+				 rx_oob->sgl[0].size, DMA_FROM_DEVICE);
 
-		free_page((unsigned long)rx_oob->buf_va);
+		put_page(virt_to_head_page(rx_oob->buf_va));
 		rx_oob->buf_va = NULL;
 	}
 
@@ -1681,6 +1709,26 @@ static void mana_destroy_rxq(struct mana_port_context *apc,
 	kfree(rxq);
 }
 
+static int mana_fill_rx_oob(struct mana_recv_buf_oob *rx_oob, u32 mem_key,
+			    struct mana_rxq *rxq, struct device *dev)
+{
+	dma_addr_t da;
+	void *va;
+
+	va = mana_get_rxfrag(rxq, dev, &da, false);
+
+	if (!va)
+		return -ENOMEM;
+
+	rx_oob->buf_va = va;
+
+	rx_oob->sgl[0].address = da;
+	rx_oob->sgl[0].size = rxq->datasize;
+	rx_oob->sgl[0].mem_key = mem_key;
+
+	return 0;
+}
+
 #define MANA_WQE_HEADER_SIZE 16
 #define MANA_WQE_SGE_SIZE 16
 
@@ -1690,11 +1738,10 @@ static int mana_alloc_rx_wqe(struct mana_port_context *apc,
 	struct gdma_context *gc = apc->ac->gdma_dev->gdma_context;
 	struct mana_recv_buf_oob *rx_oob;
 	struct device *dev = gc->dev;
-	struct page *page;
-	dma_addr_t da;
 	u32 buf_idx;
+	int ret;
 
-	WARN_ON(rxq->datasize == 0 || rxq->datasize > PAGE_SIZE);
+	WARN_ON(rxq->datasize == 0);
 
 	*rxq_size = 0;
 	*cq_size = 0;
@@ -1703,25 +1750,12 @@ static int mana_alloc_rx_wqe(struct mana_port_context *apc,
 		rx_oob = &rxq->rx_oobs[buf_idx];
 		memset(rx_oob, 0, sizeof(*rx_oob));
 
-		page = alloc_page(GFP_KERNEL);
-		if (!page)
-			return -ENOMEM;
-
-		da = dma_map_page(dev, page, XDP_PACKET_HEADROOM, rxq->datasize,
-				  DMA_FROM_DEVICE);
-
-		if (dma_mapping_error(dev, da)) {
-			__free_page(page);
-			return -ENOMEM;
-		}
-
-		rx_oob->buf_va = page_to_virt(page);
-		rx_oob->buf_dma_addr = da;
-
 		rx_oob->num_sge = 1;
-		rx_oob->sgl[0].address = rx_oob->buf_dma_addr;
-		rx_oob->sgl[0].size = rxq->datasize;
-		rx_oob->sgl[0].mem_key = apc->ac->gdma_dev->gpa_mkey;
+
+		ret = mana_fill_rx_oob(rx_oob, apc->ac->gdma_dev->gpa_mkey, rxq,
+				       dev);
+		if (ret)
+			return ret;
 
 		rx_oob->wqe_req.sgl = rx_oob->sgl;
 		rx_oob->wqe_req.num_sge = rx_oob->num_sge;
@@ -1764,6 +1798,7 @@ static struct mana_rxq *mana_create_rxq(struct mana_port_context *apc,
 	struct mana_obj_spec wq_spec;
 	struct mana_obj_spec cq_spec;
 	struct gdma_queue_spec spec;
+	unsigned int mtu = ndev->mtu;
 	struct mana_cq *cq = NULL;
 	struct gdma_context *gc;
 	u32 cq_size, rq_size;
@@ -1780,9 +1815,18 @@ static struct mana_rxq *mana_create_rxq(struct mana_port_context *apc,
 	rxq->ndev = ndev;
 	rxq->num_rx_buf = RX_BUFFERS_PER_QUEUE;
 	rxq->rxq_idx = rxq_idx;
-	rxq->datasize = ALIGN(MAX_FRAME_SIZE, 64);
 	rxq->rxobj = INVALID_MANA_HANDLE;
 
+	rxq->datasize = ALIGN(mtu + ETH_HLEN, 64);
+
+	if (mtu > MANA_XDP_MTU_MAX) {
+		rxq->alloc_size = mtu + MANA_RXBUF_PAD;
+		rxq->headroom = 0;
+	} else {
+		rxq->alloc_size = mtu + MANA_RXBUF_PAD + XDP_PACKET_HEADROOM;
+		rxq->headroom = XDP_PACKET_HEADROOM;
+	}
+
 	err = mana_alloc_rx_wqe(apc, rxq, &rq_size, &cq_size);
 	if (err)
 		goto out;
diff --git a/include/net/mana/mana.h b/include/net/mana/mana.h
index bb11a6535d80..fee99d704281 100644
--- a/include/net/mana/mana.h
+++ b/include/net/mana/mana.h
@@ -36,9 +36,6 @@ enum TRI_STATE {
 
 #define COMP_ENTRY_SIZE 64
 
-#define ADAPTER_MTU_SIZE 1500
-#define MAX_FRAME_SIZE (ADAPTER_MTU_SIZE + 14)
-
 #define RX_BUFFERS_PER_QUEUE 512
 
 #define MAX_SEND_BUFFERS_PER_QUEUE 256
@@ -282,7 +279,6 @@ struct mana_recv_buf_oob {
 	struct gdma_wqe_request wqe_req;
 
 	void *buf_va;
-	dma_addr_t buf_dma_addr;
 
 	/* SGL of the buffer going to be sent has part of the work request. */
 	u32 num_sge;
@@ -295,6 +291,11 @@ struct mana_recv_buf_oob {
 	struct gdma_posted_wqe_info wqe_inf;
 };
 
+#define MANA_RXBUF_PAD (SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) \
+			+ ETH_HLEN)
+
+#define MANA_XDP_MTU_MAX (PAGE_SIZE - MANA_RXBUF_PAD - XDP_PACKET_HEADROOM)
+
 struct mana_rxq {
 	struct gdma_queue *gdma_rq;
 	/* Cache the gdma receive queue id */
@@ -304,6 +305,8 @@ struct mana_rxq {
 	u32 rxq_idx;
 
 	u32 datasize;
+	u32 alloc_size;
+	u32 headroom;
 
 	mana_handle_t rxobj;
 
@@ -322,7 +325,7 @@ struct mana_rxq {
 
 	struct bpf_prog __rcu *bpf_prog;
 	struct xdp_rxq_info xdp_rxq;
-	struct page *xdp_save_page;
+	void *xdp_save_va; /* for reusing */
 	bool xdp_flush;
 	int xdp_rc; /* XDP redirect return code */
 
-- 
2.25.1

Re: [PATCH V2,net-next, 2/3] net: mana: Enable RX path to handle various MTU sizes

[Jesse Brandeburg]

On 4/7/2023 1:59 PM, Haiyang Zhang wrote:
> Update RX data path to allocate and use RX queue DMA buffers with
> proper size based on potentially various MTU sizes.
> 
> Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
> 
> ---
> V2:
> Refectored to multiple patches for readability. Suggested by Yunsheng Lin.

Reviewed-by: Jesse Brandeburg <jesse.brandeburg@intel.com>

One tiny nit below, but not worth a respin.

> @@ -1764,6 +1798,7 @@ static struct mana_rxq *mana_create_rxq(struct mana_port_context *apc,
>  	struct mana_obj_spec wq_spec;
>  	struct mana_obj_spec cq_spec;
>  	struct gdma_queue_spec spec;
> +	unsigned int mtu = ndev->mtu;

This one isn't quite RCT order. I'd only change it if you have another
respin for some reason.

Ha, I see you remove that line in the next patch, never mind...

Re: [PATCH V2,net-next, 2/3] net: mana: Enable RX path to handle various MTU sizes

[Jacob Keller]

On 4/7/2023 1:59 PM, Haiyang Zhang wrote:
> Update RX data path to allocate and use RX queue DMA buffers with
> proper size based on potentially various MTU sizes.
> 
> Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
> 
> ---
> V2:
> Refectored to multiple patches for readability. Suggested by Yunsheng Lin.
> 
> ---
>  drivers/net/ethernet/microsoft/mana/mana_en.c | 188 +++++++++++-------
>  include/net/mana/mana.h                       |  13 +-
>  2 files changed, 124 insertions(+), 77 deletions(-)
> 
> diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
> index 112c642dc89b..e5d5dea763f2 100644
> --- a/drivers/net/ethernet/microsoft/mana/mana_en.c
> +++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
> @@ -1185,10 +1185,10 @@ static void mana_post_pkt_rxq(struct mana_rxq *rxq)
>  	WARN_ON_ONCE(recv_buf_oob->wqe_inf.wqe_size_in_bu != 1);
>  }
>  
> -static struct sk_buff *mana_build_skb(void *buf_va, uint pkt_len,
> -				      struct xdp_buff *xdp)
> +static struct sk_buff *mana_build_skb(struct mana_rxq *rxq, void *buf_va,
> +				      uint pkt_len, struct xdp_buff *xdp)
>  {
> -	struct sk_buff *skb = napi_build_skb(buf_va, PAGE_SIZE);
> +	struct sk_buff *skb = napi_build_skb(buf_va, rxq->alloc_size);
>  
>  	if (!skb)
>  		return NULL;
> @@ -1196,11 +1196,12 @@ static struct sk_buff *mana_build_skb(void *buf_va, uint pkt_len,
>  	if (xdp->data_hard_start) {
>  		skb_reserve(skb, xdp->data - xdp->data_hard_start);
>  		skb_put(skb, xdp->data_end - xdp->data);
> -	} else {
> -		skb_reserve(skb, XDP_PACKET_HEADROOM);
> -		skb_put(skb, pkt_len);
> +		return skb;
>  	}
>  
> +	skb_reserve(skb, rxq->headroom);
> +	skb_put(skb, pkt_len);
> +
>  	return skb;
>  }
>  
> @@ -1233,7 +1234,7 @@ static void mana_rx_skb(void *buf_va, struct mana_rxcomp_oob *cqe,
>  	if (act != XDP_PASS && act != XDP_TX)
>  		goto drop_xdp;
>  
> -	skb = mana_build_skb(buf_va, pkt_len, &xdp);
> +	skb = mana_build_skb(rxq, buf_va, pkt_len, &xdp);
>  
>  	if (!skb)
>  		goto drop;
> @@ -1282,14 +1283,72 @@ static void mana_rx_skb(void *buf_va, struct mana_rxcomp_oob *cqe,
>  	u64_stats_update_end(&rx_stats->syncp);
>  
>  drop:
> -	WARN_ON_ONCE(rxq->xdp_save_page);
> -	rxq->xdp_save_page = virt_to_page(buf_va);
> +	WARN_ON_ONCE(rxq->xdp_save_va);
> +	/* Save for reuse */
> +	rxq->xdp_save_va = buf_va;
>  
>  	++ndev->stats.rx_dropped;
>  
>  	return;
>  }
>  
> +static void *mana_get_rxfrag(struct mana_rxq *rxq, struct device *dev,
> +			     dma_addr_t *da, bool is_napi)
> +{
> +	struct page *page;
> +	void *va;
> +
> +	/* Reuse XDP dropped page if available */
> +	if (rxq->xdp_save_va) {
> +		va = rxq->xdp_save_va;
> +		rxq->xdp_save_va = NULL;
> +	} else if (rxq->alloc_size > PAGE_SIZE) {
> +		if (is_napi)
> +			va = napi_alloc_frag(rxq->alloc_size);
> +		else
> +			va = netdev_alloc_frag(rxq->alloc_size);
> +
> +		if (!va)
> +			return NULL;
> +	} else {
> +		page = dev_alloc_page();
> +		if (!page)
> +			return NULL;
> +
> +		va = page_to_virt(page);
> +	}
> +
> +	*da = dma_map_single(dev, va + rxq->headroom, rxq->datasize,
> +			     DMA_FROM_DEVICE);
> +
> +	if (dma_mapping_error(dev, *da)) {
> +		put_page(virt_to_head_page(va));
> +		return NULL;
> +	}
> +
> +	return va;
> +}
> +
> +/* Allocate frag for rx buffer, and save the old buf */
> +static void mana_refill_rxoob(struct device *dev, struct mana_rxq *rxq,
> +			      struct mana_recv_buf_oob *rxoob, void **old_buf)
> +{
> +	dma_addr_t da;
> +	void *va;
> +
> +	va = mana_get_rxfrag(rxq, dev, &da, true);
> +
> +	if (!va)
> +		return;
> +
> +	dma_unmap_single(dev, rxoob->sgl[0].address, rxq->datasize,
> +			 DMA_FROM_DEVICE);
> +	*old_buf = rxoob->buf_va;
> +
> +	rxoob->buf_va = va;
> +	rxoob->sgl[0].address = da;
> +}
> +

So you're pulling out these functions from the code below, which is
good, but it makes it hard to tell what code actually changed.

>  static void mana_process_rx_cqe(struct mana_rxq *rxq, struct mana_cq *cq,
>  				struct gdma_comp *cqe)
>  {
> @@ -1299,10 +1358,8 @@ static void mana_process_rx_cqe(struct mana_rxq *rxq, struct mana_cq *cq,
>  	struct mana_recv_buf_oob *rxbuf_oob;
>  	struct mana_port_context *apc;
>  	struct device *dev = gc->dev;
> -	void *new_buf, *old_buf;
> -	struct page *new_page;
> +	void *old_buf = NULL;
>  	u32 curr, pktlen;
> -	dma_addr_t da;
>  
>  	apc = netdev_priv(ndev);
>  
> @@ -1345,40 +1402,11 @@ static void mana_process_rx_cqe(struct mana_rxq *rxq, struct mana_cq *cq,
>  	rxbuf_oob = &rxq->rx_oobs[curr];
>  	WARN_ON_ONCE(rxbuf_oob->wqe_inf.wqe_size_in_bu != 1);
>  
> -	/* Reuse XDP dropped page if available */
> -	if (rxq->xdp_save_page) {
> -		new_page = rxq->xdp_save_page;
> -		rxq->xdp_save_page = NULL;
> -	} else {
> -		new_page = alloc_page(GFP_ATOMIC);
> -	}
> -
> -	if (new_page) {
> -		da = dma_map_page(dev, new_page, XDP_PACKET_HEADROOM, rxq->datasize,
> -				  DMA_FROM_DEVICE);
> -
> -		if (dma_mapping_error(dev, da)) {
> -			__free_page(new_page);
> -			new_page = NULL;
> -		}
> -	}
> -
> -	new_buf = new_page ? page_to_virt(new_page) : NULL;
> -
> -	if (new_buf) {
> -		dma_unmap_page(dev, rxbuf_oob->buf_dma_addr, rxq->datasize,
> -			       DMA_FROM_DEVICE);
> -
> -		old_buf = rxbuf_oob->buf_va;
> -
> -		/* refresh the rxbuf_oob with the new page */
> -		rxbuf_oob->buf_va = new_buf;
> -		rxbuf_oob->buf_dma_addr = da;
> -		rxbuf_oob->sgl[0].address = rxbuf_oob->buf_dma_addr;
> -	} else {
> -		old_buf = NULL; /* drop the packet if no memory */
> -	}

Could you do this split into helper functions first in a separate change
before adding support for handling various MTU size?

Doing it that way would make it much easier to review what actually
changes in that block of code.

Thanks,
Jake

RE: [PATCH V2,net-next, 2/3] net: mana: Enable RX path to handle various MTU sizes

[Haiyang Zhang]

> -----Original Message-----
> From: Jacob Keller <jacob.e.keller@intel.com>
> Sent: Tuesday, April 11, 2023 7:11 PM
> To: Haiyang Zhang <haiyangz@microsoft.com>; linux-hyperv@vger.kernel.org;
> netdev@vger.kernel.org
> Cc: Dexuan Cui <decui@microsoft.com>; KY Srinivasan <kys@microsoft.com>;
> Paul Rosswurm <paulros@microsoft.com>; olaf@aepfle.de;
> vkuznets@redhat.com; davem@davemloft.net; wei.liu@kernel.org;
> edumazet@google.com; kuba@kernel.org; pabeni@redhat.com;
> leon@kernel.org; Long Li <longli@microsoft.com>;
> ssengar@linux.microsoft.com; linux-rdma@vger.kernel.org;
> daniel@iogearbox.net; john.fastabend@gmail.com; bpf@vger.kernel.org;
> ast@kernel.org; Ajay Sharma <sharmaajay@microsoft.com>;
> hawk@kernel.org; linux-kernel@vger.kernel.org
> Subject: Re: [PATCH V2,net-next, 2/3] net: mana: Enable RX path to handle
> various MTU sizes
> 
> 
> 
> On 4/7/2023 1:59 PM, Haiyang Zhang wrote:
> > Update RX data path to allocate and use RX queue DMA buffers with
> > proper size based on potentially various MTU sizes.
> >
> > Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
> >
> > ---
> > V2:
> > Refectored to multiple patches for readability. Suggested by Yunsheng Lin.
> >
> > ---
> >  drivers/net/ethernet/microsoft/mana/mana_en.c | 188 +++++++++++------
> -
> >  include/net/mana/mana.h                       |  13 +-
> >  2 files changed, 124 insertions(+), 77 deletions(-)
> >
> > diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c
> b/drivers/net/ethernet/microsoft/mana/mana_en.c
> > index 112c642dc89b..e5d5dea763f2 100644
> > --- a/drivers/net/ethernet/microsoft/mana/mana_en.c
> > +++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
> > @@ -1185,10 +1185,10 @@ static void mana_post_pkt_rxq(struct
> mana_rxq *rxq)
> >  	WARN_ON_ONCE(recv_buf_oob->wqe_inf.wqe_size_in_bu != 1);
> >  }
> >
> > -static struct sk_buff *mana_build_skb(void *buf_va, uint pkt_len,
> > -				      struct xdp_buff *xdp)
> > +static struct sk_buff *mana_build_skb(struct mana_rxq *rxq, void *buf_va,
> > +				      uint pkt_len, struct xdp_buff *xdp)
> >  {
> > -	struct sk_buff *skb = napi_build_skb(buf_va, PAGE_SIZE);
> > +	struct sk_buff *skb = napi_build_skb(buf_va, rxq->alloc_size);
> >
> >  	if (!skb)
> >  		return NULL;
> > @@ -1196,11 +1196,12 @@ static struct sk_buff *mana_build_skb(void
> *buf_va, uint pkt_len,
> >  	if (xdp->data_hard_start) {
> >  		skb_reserve(skb, xdp->data - xdp->data_hard_start);
> >  		skb_put(skb, xdp->data_end - xdp->data);
> > -	} else {
> > -		skb_reserve(skb, XDP_PACKET_HEADROOM);
> > -		skb_put(skb, pkt_len);
> > +		return skb;
> >  	}
> >
> > +	skb_reserve(skb, rxq->headroom);
> > +	skb_put(skb, pkt_len);
> > +
> >  	return skb;
> >  }
> >
> > @@ -1233,7 +1234,7 @@ static void mana_rx_skb(void *buf_va, struct
> mana_rxcomp_oob *cqe,
> >  	if (act != XDP_PASS && act != XDP_TX)
> >  		goto drop_xdp;
> >
> > -	skb = mana_build_skb(buf_va, pkt_len, &xdp);
> > +	skb = mana_build_skb(rxq, buf_va, pkt_len, &xdp);
> >
> >  	if (!skb)
> >  		goto drop;
> > @@ -1282,14 +1283,72 @@ static void mana_rx_skb(void *buf_va, struct
> mana_rxcomp_oob *cqe,
> >  	u64_stats_update_end(&rx_stats->syncp);
> >
> >  drop:
> > -	WARN_ON_ONCE(rxq->xdp_save_page);
> > -	rxq->xdp_save_page = virt_to_page(buf_va);
> > +	WARN_ON_ONCE(rxq->xdp_save_va);
> > +	/* Save for reuse */
> > +	rxq->xdp_save_va = buf_va;
> >
> >  	++ndev->stats.rx_dropped;
> >
> >  	return;
> >  }
> >
> > +static void *mana_get_rxfrag(struct mana_rxq *rxq, struct device *dev,
> > +			     dma_addr_t *da, bool is_napi)
> > +{
> > +	struct page *page;
> > +	void *va;
> > +
> > +	/* Reuse XDP dropped page if available */
> > +	if (rxq->xdp_save_va) {
> > +		va = rxq->xdp_save_va;
> > +		rxq->xdp_save_va = NULL;
> > +	} else if (rxq->alloc_size > PAGE_SIZE) {
> > +		if (is_napi)
> > +			va = napi_alloc_frag(rxq->alloc_size);
> > +		else
> > +			va = netdev_alloc_frag(rxq->alloc_size);
> > +
> > +		if (!va)
> > +			return NULL;
> > +	} else {
> > +		page = dev_alloc_page();
> > +		if (!page)
> > +			return NULL;
> > +
> > +		va = page_to_virt(page);
> > +	}
> > +
> > +	*da = dma_map_single(dev, va + rxq->headroom, rxq->datasize,
> > +			     DMA_FROM_DEVICE);
> > +
> > +	if (dma_mapping_error(dev, *da)) {
> > +		put_page(virt_to_head_page(va));
> > +		return NULL;
> > +	}
> > +
> > +	return va;
> > +}
> > +
> > +/* Allocate frag for rx buffer, and save the old buf */
> > +static void mana_refill_rxoob(struct device *dev, struct mana_rxq *rxq,
> > +			      struct mana_recv_buf_oob *rxoob, void
> **old_buf)
> > +{
> > +	dma_addr_t da;
> > +	void *va;
> > +
> > +	va = mana_get_rxfrag(rxq, dev, &da, true);
> > +
> > +	if (!va)
> > +		return;
> > +
> > +	dma_unmap_single(dev, rxoob->sgl[0].address, rxq->datasize,
> > +			 DMA_FROM_DEVICE);
> > +	*old_buf = rxoob->buf_va;
> > +
> > +	rxoob->buf_va = va;
> > +	rxoob->sgl[0].address = da;
> > +}
> > +
> 
> So you're pulling out these functions from the code below, which is
> good, but it makes it hard to tell what code actually changed.
> 
> >  static void mana_process_rx_cqe(struct mana_rxq *rxq, struct mana_cq *cq,
> >  				struct gdma_comp *cqe)
> >  {
> > @@ -1299,10 +1358,8 @@ static void mana_process_rx_cqe(struct
> mana_rxq *rxq, struct mana_cq *cq,
> >  	struct mana_recv_buf_oob *rxbuf_oob;
> >  	struct mana_port_context *apc;
> >  	struct device *dev = gc->dev;
> > -	void *new_buf, *old_buf;
> > -	struct page *new_page;
> > +	void *old_buf = NULL;
> >  	u32 curr, pktlen;
> > -	dma_addr_t da;
> >
> >  	apc = netdev_priv(ndev);
> >
> > @@ -1345,40 +1402,11 @@ static void mana_process_rx_cqe(struct
> mana_rxq *rxq, struct mana_cq *cq,
> >  	rxbuf_oob = &rxq->rx_oobs[curr];
> >  	WARN_ON_ONCE(rxbuf_oob->wqe_inf.wqe_size_in_bu != 1);
> >
> > -	/* Reuse XDP dropped page if available */
> > -	if (rxq->xdp_save_page) {
> > -		new_page = rxq->xdp_save_page;
> > -		rxq->xdp_save_page = NULL;
> > -	} else {
> > -		new_page = alloc_page(GFP_ATOMIC);
> > -	}
> > -
> > -	if (new_page) {
> > -		da = dma_map_page(dev, new_page,
> XDP_PACKET_HEADROOM, rxq->datasize,
> > -				  DMA_FROM_DEVICE);
> > -
> > -		if (dma_mapping_error(dev, da)) {
> > -			__free_page(new_page);
> > -			new_page = NULL;
> > -		}
> > -	}
> > -
> > -	new_buf = new_page ? page_to_virt(new_page) : NULL;
> > -
> > -	if (new_buf) {
> > -		dma_unmap_page(dev, rxbuf_oob->buf_dma_addr, rxq-
> >datasize,
> > -			       DMA_FROM_DEVICE);
> > -
> > -		old_buf = rxbuf_oob->buf_va;
> > -
> > -		/* refresh the rxbuf_oob with the new page */
> > -		rxbuf_oob->buf_va = new_buf;
> > -		rxbuf_oob->buf_dma_addr = da;
> > -		rxbuf_oob->sgl[0].address = rxbuf_oob->buf_dma_addr;
> > -	} else {
> > -		old_buf = NULL; /* drop the packet if no memory */
> > -	}
> 
> Could you do this split into helper functions first in a separate change
> before adding support for handling various MTU size?
> 
> Doing it that way would make it much easier to review what actually
> changes in that block of code.

Will do.

Thanks,
- Haiyang

[PATCH V2,net-next, 3/3] net: mana: Add support for jumbo frame

[Haiyang Zhang]

During probe, get the hardware-allowed max MTU by querying the device
configuration. Users can select MTU up to the device limit.
When XDP is in use, limit MTU settings so the buffer size is within
one page.
Also, to prevent changing MTU fails, and leaves the NIC in a bad state,
pre-allocate all buffers before starting the change. So in low memory
condition, it will return error, without affecting the NIC.

Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
---
V2:
Refectored to multiple patches for readability. Suggested by Yunsheng Lin.
Added pre-allocation of buffers to avoid changing MTU fails in a bad state.
 Suggested by Leon Romanovsky, Francois Romieu.
---
 .../net/ethernet/microsoft/mana/mana_bpf.c    |  22 +-
 drivers/net/ethernet/microsoft/mana/mana_en.c | 217 ++++++++++++++++--
 include/net/mana/gdma.h                       |   4 +
 include/net/mana/mana.h                       |  14 ++
 4 files changed, 233 insertions(+), 24 deletions(-)

diff --git a/drivers/net/ethernet/microsoft/mana/mana_bpf.c b/drivers/net/ethernet/microsoft/mana/mana_bpf.c
index 3caea631229c..23b1521c0df9 100644
--- a/drivers/net/ethernet/microsoft/mana/mana_bpf.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_bpf.c
@@ -133,12 +133,6 @@ u32 mana_run_xdp(struct net_device *ndev, struct mana_rxq *rxq,
 	return act;
 }
 
-static unsigned int mana_xdp_fraglen(unsigned int len)
-{
-	return SKB_DATA_ALIGN(len) +
-	       SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
-}
-
 struct bpf_prog *mana_xdp_get(struct mana_port_context *apc)
 {
 	ASSERT_RTNL();
@@ -179,17 +173,18 @@ static int mana_xdp_set(struct net_device *ndev, struct bpf_prog *prog,
 {
 	struct mana_port_context *apc = netdev_priv(ndev);
 	struct bpf_prog *old_prog;
-	int buf_max;
+	struct gdma_context *gc;
+
+	gc = apc->ac->gdma_dev->gdma_context;
 
 	old_prog = mana_xdp_get(apc);
 
 	if (!old_prog && !prog)
 		return 0;
 
-	buf_max = XDP_PACKET_HEADROOM + mana_xdp_fraglen(ndev->mtu + ETH_HLEN);
-	if (prog && buf_max > PAGE_SIZE) {
-		netdev_err(ndev, "XDP: mtu:%u too large, buf_max:%u\n",
-			   ndev->mtu, buf_max);
+	if (prog && ndev->mtu > MANA_XDP_MTU_MAX) {
+		netdev_err(ndev, "XDP: mtu:%u too large, mtu_max:%lu\n",
+			   ndev->mtu, MANA_XDP_MTU_MAX);
 		NL_SET_ERR_MSG_MOD(extack, "XDP: mtu too large");
 
 		return -EOPNOTSUPP;
@@ -206,6 +201,11 @@ static int mana_xdp_set(struct net_device *ndev, struct bpf_prog *prog,
 	if (apc->port_is_up)
 		mana_chn_setxdp(apc, prog);
 
+	if (prog)
+		ndev->max_mtu = MANA_XDP_MTU_MAX;
+	else
+		ndev->max_mtu = gc->adapter_mtu - ETH_HLEN;
+
 	return 0;
 }
 
diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
index e5d5dea763f2..cabecbfa1102 100644
--- a/drivers/net/ethernet/microsoft/mana/mana_en.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
@@ -427,6 +427,192 @@ static u16 mana_select_queue(struct net_device *ndev, struct sk_buff *skb,
 	return txq;
 }
 
+/* Release pre-allocated RX buffers */
+static void mana_pre_dealloc_rxbufs(struct mana_port_context *mpc)
+{
+	struct device *dev;
+	int i;
+
+	dev = mpc->ac->gdma_dev->gdma_context->dev;
+
+	if (!mpc->rxbufs_pre)
+		goto out1;
+
+	if (!mpc->das_pre)
+		goto out2;
+
+	while (mpc->rxbpre_total) {
+		i = --mpc->rxbpre_total;
+		dma_unmap_single(dev, mpc->das_pre[i], mpc->rxbpre_datasize,
+				 DMA_FROM_DEVICE);
+		put_page(virt_to_head_page(mpc->rxbufs_pre[i]));
+	}
+
+	kfree(mpc->das_pre);
+	mpc->das_pre = NULL;
+
+out2:
+	kfree(mpc->rxbufs_pre);
+	mpc->rxbufs_pre = NULL;
+
+out1:
+	mpc->rxbpre_datasize = 0;
+	mpc->rxbpre_alloc_size = 0;
+	mpc->rxbpre_headroom = 0;
+}
+
+/* Get a buffer from the pre-allocated RX buffers */
+static void *mana_get_rxbuf_pre(struct mana_rxq *rxq, dma_addr_t *da)
+{
+	struct net_device *ndev = rxq->ndev;
+	struct mana_port_context *mpc;
+	void *va;
+
+	mpc = netdev_priv(ndev);
+
+	if (!mpc->rxbufs_pre || !mpc->das_pre || !mpc->rxbpre_total) {
+		netdev_err(ndev, "No RX pre-allocated bufs\n");
+		return NULL;
+	}
+
+	/* Check sizes to catch unexpected coding error */
+	if (mpc->rxbpre_datasize != rxq->datasize) {
+		netdev_err(ndev, "rxbpre_datasize mismatch: %u: %u\n",
+			   mpc->rxbpre_datasize, rxq->datasize);
+		return NULL;
+	}
+
+	if (mpc->rxbpre_alloc_size != rxq->alloc_size) {
+		netdev_err(ndev, "rxbpre_alloc_size mismatch: %u: %u\n",
+			   mpc->rxbpre_alloc_size, rxq->alloc_size);
+		return NULL;
+	}
+
+	if (mpc->rxbpre_headroom != rxq->headroom) {
+		netdev_err(ndev, "rxbpre_headroom mismatch: %u: %u\n",
+			   mpc->rxbpre_headroom, rxq->headroom);
+		return NULL;
+	}
+
+	mpc->rxbpre_total--;
+
+	*da = mpc->das_pre[mpc->rxbpre_total];
+	va = mpc->rxbufs_pre[mpc->rxbpre_total];
+	mpc->rxbufs_pre[mpc->rxbpre_total] = NULL;
+
+	/* Deallocate the array after all buffers are gone */
+	if (!mpc->rxbpre_total)
+		mana_pre_dealloc_rxbufs(mpc);
+
+	return va;
+}
+
+/* Get RX buffer's data size, alloc size, XDP headroom based on MTU */
+static void mana_get_rxbuf_cfg(int mtu, u32 *datasize, u32 *alloc_size,
+			       u32 *headroom)
+{
+	if (mtu > MANA_XDP_MTU_MAX)
+		*headroom = 0; /* no support for XDP */
+	else
+		*headroom = XDP_PACKET_HEADROOM;
+
+	*alloc_size = mtu + MANA_RXBUF_PAD + *headroom;
+
+	*datasize = ALIGN(mtu + ETH_HLEN, MANA_RX_DATA_ALIGN);
+}
+
+static int mana_pre_alloc_rxbufs(struct mana_port_context *mpc, int new_mtu)
+{
+	struct device *dev;
+	struct page *page;
+	dma_addr_t da;
+	int num_rxb;
+	void *va;
+	int i;
+
+	mana_get_rxbuf_cfg(new_mtu, &mpc->rxbpre_datasize,
+			   &mpc->rxbpre_alloc_size, &mpc->rxbpre_headroom);
+
+	dev = mpc->ac->gdma_dev->gdma_context->dev;
+
+	num_rxb = mpc->num_queues * RX_BUFFERS_PER_QUEUE;
+
+	WARN(mpc->rxbufs_pre, "mana rxbufs_pre exists\n");
+	mpc->rxbufs_pre = kmalloc_array(num_rxb, sizeof(void *), GFP_KERNEL);
+	if (!mpc->rxbufs_pre)
+		goto error;
+
+	mpc->das_pre = kmalloc_array(num_rxb, sizeof(dma_addr_t), GFP_KERNEL);
+	if (!mpc->das_pre)
+		goto error;
+
+	mpc->rxbpre_total = 0;
+
+	for (i = 0; i < num_rxb; i++) {
+		if (mpc->rxbpre_alloc_size > PAGE_SIZE) {
+			va = netdev_alloc_frag(mpc->rxbpre_alloc_size);
+			if (!va)
+				goto error;
+		} else {
+			page = dev_alloc_page();
+			if (!page)
+				goto error;
+
+			va = page_to_virt(page);
+		}
+
+		da = dma_map_single(dev, va + mpc->rxbpre_headroom,
+				    mpc->rxbpre_datasize, DMA_FROM_DEVICE);
+
+		if (dma_mapping_error(dev, da)) {
+			put_page(virt_to_head_page(va));
+			goto error;
+		}
+
+		mpc->rxbufs_pre[i] = va;
+		mpc->das_pre[i] = da;
+		mpc->rxbpre_total = i + 1;
+	}
+
+	return 0;
+
+error:
+	mana_pre_dealloc_rxbufs(mpc);
+	return -ENOMEM;
+}
+
+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;
+	int err;
+
+	/* Pre-allocate buffers to prevent failure in mana_attach later */
+	err = mana_pre_alloc_rxbufs(mpc, new_mtu);
+	if (err) {
+		netdev_err(ndev, "Insufficient memory for new MTU\n");
+		return err;
+	}
+
+	err = mana_detach(ndev, false);
+	if (err) {
+		netdev_err(ndev, "mana_detach failed: %d\n", err);
+		goto out;
+	}
+
+	ndev->mtu = new_mtu;
+
+	err = mana_attach(ndev);
+	if (err) {
+		netdev_err(ndev, "mana_attach failed: %d\n", err);
+		ndev->mtu = old_mtu;
+	}
+
+out:
+	mana_pre_dealloc_rxbufs(mpc);
+	return err;
+}
+
 static const struct net_device_ops mana_devops = {
 	.ndo_open		= mana_open,
 	.ndo_stop		= mana_close,
@@ -436,6 +622,7 @@ static const struct net_device_ops mana_devops = {
 	.ndo_get_stats64	= mana_get_stats64,
 	.ndo_bpf		= mana_bpf,
 	.ndo_xdp_xmit		= mana_xdp_xmit,
+	.ndo_change_mtu		= mana_change_mtu,
 };
 
 static void mana_cleanup_port_context(struct mana_port_context *apc)
@@ -625,6 +812,9 @@ static int mana_query_device_cfg(struct mana_context *ac, u32 proto_major_ver,
 
 	mana_gd_init_req_hdr(&req.hdr, MANA_QUERY_DEV_CONFIG,
 			     sizeof(req), sizeof(resp));
+
+	req.hdr.resp.msg_version = GDMA_MESSAGE_V2;
+
 	req.proto_major_ver = proto_major_ver;
 	req.proto_minor_ver = proto_minor_ver;
 	req.proto_micro_ver = proto_micro_ver;
@@ -647,6 +837,11 @@ static int mana_query_device_cfg(struct mana_context *ac, u32 proto_major_ver,
 
 	*max_num_vports = resp.max_num_vports;
 
+	if (resp.hdr.response.msg_version == GDMA_MESSAGE_V2)
+		gc->adapter_mtu = resp.adapter_mtu;
+	else
+		gc->adapter_mtu = ETH_FRAME_LEN;
+
 	return 0;
 }
 
@@ -1712,10 +1907,14 @@ static void mana_destroy_rxq(struct mana_port_context *apc,
 static int mana_fill_rx_oob(struct mana_recv_buf_oob *rx_oob, u32 mem_key,
 			    struct mana_rxq *rxq, struct device *dev)
 {
+	struct mana_port_context *mpc = netdev_priv(rxq->ndev);
 	dma_addr_t da;
 	void *va;
 
-	va = mana_get_rxfrag(rxq, dev, &da, false);
+	if (mpc->rxbufs_pre)
+		va = mana_get_rxbuf_pre(rxq, &da);
+	else
+		va = mana_get_rxfrag(rxq, dev, &da, false);
 
 	if (!va)
 		return -ENOMEM;
@@ -1798,7 +1997,6 @@ static struct mana_rxq *mana_create_rxq(struct mana_port_context *apc,
 	struct mana_obj_spec wq_spec;
 	struct mana_obj_spec cq_spec;
 	struct gdma_queue_spec spec;
-	unsigned int mtu = ndev->mtu;
 	struct mana_cq *cq = NULL;
 	struct gdma_context *gc;
 	u32 cq_size, rq_size;
@@ -1817,15 +2015,8 @@ static struct mana_rxq *mana_create_rxq(struct mana_port_context *apc,
 	rxq->rxq_idx = rxq_idx;
 	rxq->rxobj = INVALID_MANA_HANDLE;
 
-	rxq->datasize = ALIGN(mtu + ETH_HLEN, 64);
-
-	if (mtu > MANA_XDP_MTU_MAX) {
-		rxq->alloc_size = mtu + MANA_RXBUF_PAD;
-		rxq->headroom = 0;
-	} else {
-		rxq->alloc_size = mtu + MANA_RXBUF_PAD + XDP_PACKET_HEADROOM;
-		rxq->headroom = XDP_PACKET_HEADROOM;
-	}
+	mana_get_rxbuf_cfg(ndev->mtu, &rxq->datasize, &rxq->alloc_size,
+			   &rxq->headroom);
 
 	err = mana_alloc_rx_wqe(apc, rxq, &rq_size, &cq_size);
 	if (err)
@@ -2238,8 +2429,8 @@ static int mana_probe_port(struct mana_context *ac, int port_idx,
 	ndev->netdev_ops = &mana_devops;
 	ndev->ethtool_ops = &mana_ethtool_ops;
 	ndev->mtu = ETH_DATA_LEN;
-	ndev->max_mtu = ndev->mtu;
-	ndev->min_mtu = ndev->mtu;
+	ndev->max_mtu = gc->adapter_mtu - ETH_HLEN;
+	ndev->min_mtu = ETH_MIN_MTU;
 	ndev->needed_headroom = MANA_HEADROOM;
 	ndev->dev_port = port_idx;
 	SET_NETDEV_DEV(ndev, gc->dev);
diff --git a/include/net/mana/gdma.h b/include/net/mana/gdma.h
index 56189e4252da..96c120160f15 100644
--- a/include/net/mana/gdma.h
+++ b/include/net/mana/gdma.h
@@ -145,6 +145,7 @@ struct gdma_general_req {
 }; /* HW DATA */
 
 #define GDMA_MESSAGE_V1 1
+#define GDMA_MESSAGE_V2 2
 
 struct gdma_general_resp {
 	struct gdma_resp_hdr hdr;
@@ -354,6 +355,9 @@ struct gdma_context {
 	struct gdma_resource	msix_resource;
 	struct gdma_irq_context	*irq_contexts;
 
+	/* L2 MTU */
+	u16 adapter_mtu;
+
 	/* This maps a CQ index to the queue structure. */
 	unsigned int		max_num_cqs;
 	struct gdma_queue	**cq_table;
diff --git a/include/net/mana/mana.h b/include/net/mana/mana.h
index fee99d704281..cd386aa7c7cc 100644
--- a/include/net/mana/mana.h
+++ b/include/net/mana/mana.h
@@ -37,6 +37,7 @@ enum TRI_STATE {
 #define COMP_ENTRY_SIZE 64
 
 #define RX_BUFFERS_PER_QUEUE 512
+#define MANA_RX_DATA_ALIGN 64
 
 #define MAX_SEND_BUFFERS_PER_QUEUE 256
 
@@ -390,6 +391,14 @@ struct mana_port_context {
 	/* This points to an array of num_queues of RQ pointers. */
 	struct mana_rxq **rxqs;
 
+	/* pre-allocated rx buffer array */
+	void **rxbufs_pre;
+	dma_addr_t *das_pre;
+	int rxbpre_total;
+	u32 rxbpre_datasize;
+	u32 rxbpre_alloc_size;
+	u32 rxbpre_headroom;
+
 	struct bpf_prog *bpf_prog;
 
 	/* Create num_queues EQs, SQs, SQ-CQs, RQs and RQ-CQs, respectively. */
@@ -489,6 +498,11 @@ struct mana_query_device_cfg_resp {
 	u16 max_num_vports;
 	u16 reserved;
 	u32 max_num_eqs;
+
+	/* response v2: */
+	u16 adapter_mtu;
+	u16 reserved2;
+	u32 reserved3;
 }; /* HW DATA */
 
 /* Query vPort Configuration */
-- 
2.25.1

Re: [PATCH V2,net-next, 3/3] net: mana: Add support for jumbo frame

[Jesse Brandeburg]

On 4/7/2023 1:59 PM, Haiyang Zhang wrote:
> During probe, get the hardware-allowed max MTU by querying the device
> configuration. Users can select MTU up to the device limit.
> When XDP is in use, limit MTU settings so the buffer size is within
> one page.
> Also, to prevent changing MTU fails, and leaves the NIC in a bad state,
> pre-allocate all buffers before starting the change. So in low memory
> condition, it will return error, without affecting the NIC.
> 
> Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>

Reviewed-by: Jesse Brandeburg <jesse.brandeburg@intel.com>

Re: [PATCH V2,net-next, 3/3] net: mana: Add support for jumbo frame

[Jacob Keller]

On 4/7/2023 1:59 PM, Haiyang Zhang wrote:
> During probe, get the hardware-allowed max MTU by querying the device
> configuration. Users can select MTU up to the device limit.
> When XDP is in use, limit MTU settings so the buffer size is within
> one page.
> Also, to prevent changing MTU fails, and leaves the NIC in a bad state,
> pre-allocate all buffers before starting the change. So in low memory
> condition, it will return error, without affecting the NIC.
> 

What happens if XDP gets enabled after MTU larger than PAGE_SIZE is set?
Will XDP fail to enable in that case?

Thanks,
Jake

RE: [PATCH V2,net-next, 3/3] net: mana: Add support for jumbo frame

[Haiyang Zhang]

> -----Original Message-----
> From: Jacob Keller <jacob.e.keller@intel.com>
> Sent: Tuesday, April 11, 2023 7:13 PM
> To: Haiyang Zhang <haiyangz@microsoft.com>; linux-hyperv@vger.kernel.org;
> netdev@vger.kernel.org
> Cc: Dexuan Cui <decui@microsoft.com>; KY Srinivasan <kys@microsoft.com>;
> Paul Rosswurm <paulros@microsoft.com>; olaf@aepfle.de;
> vkuznets@redhat.com; davem@davemloft.net; wei.liu@kernel.org;
> edumazet@google.com; kuba@kernel.org; pabeni@redhat.com;
> leon@kernel.org; Long Li <longli@microsoft.com>;
> ssengar@linux.microsoft.com; linux-rdma@vger.kernel.org;
> daniel@iogearbox.net; john.fastabend@gmail.com; bpf@vger.kernel.org;
> ast@kernel.org; Ajay Sharma <sharmaajay@microsoft.com>;
> hawk@kernel.org; linux-kernel@vger.kernel.org
> Subject: Re: [PATCH V2,net-next, 3/3] net: mana: Add support for jumbo
> frame
> 
> 
> 
> On 4/7/2023 1:59 PM, Haiyang Zhang wrote:
> > During probe, get the hardware-allowed max MTU by querying the device
> > configuration. Users can select MTU up to the device limit.
> > When XDP is in use, limit MTU settings so the buffer size is within
> > one page.
> > Also, to prevent changing MTU fails, and leaves the NIC in a bad state,
> > pre-allocate all buffers before starting the change. So in low memory
> > condition, it will return error, without affecting the NIC.
> >
> 
> What happens if XDP gets enabled after MTU larger than PAGE_SIZE is set?
> Will XDP fail to enable in that case?

Yes, XDP program will fail to enable if MTU is too large.

Thanks,
- Haiyang