On Mon, Aug 26, 2024 at 09:07:41AM -0700, Shradha Gupta wrote:
> Currently the values of WQs for RX and TX queues for MANA devices
> are hardcoded to default sizes.
> Allow configuring these values for MANA devices as ringparam
> configuration(get/set) through ethtool_ops.
> Pre-allocate buffers at the beginning of this operation, to
> prevent complete network loss in low-memory conditions.
>
> Signed-off-by: Shradha Gupta <shradhagu...@linux.microsoft.com>
> Reviewed-by: Haiyang Zhang <haiya...@microsoft.com>
> ---
> Changes in v5:
> * Explained comment better about not using MANA_PAGE_ALIGN
> * remove unnecessay MANA_PAGE_ALIGN step for cq_size
> ---
> Changes in v4:
> * if not apower of two, find the nearest power of 2 value and
> use it as ring parameter
> * Skip the max value check for parameters
> ---
> Changes in v3:
> * pre-allocate buffers before changing the queue sizes
> * rebased to latest net-next
> ---
> Changes in v2:
> * Removed unnecessary validations in mana_set_ringparam()
> * Fixed codespell error
> * Improved error message to indicate issue with the parameter
> ---
> drivers/net/ethernet/microsoft/mana/mana_en.c | 27 ++++---
> .../ethernet/microsoft/mana/mana_ethtool.c | 74 +++++++++++++++++++
> include/net/mana/mana.h | 23 +++++-
> 3 files changed, 110 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c
> b/drivers/net/ethernet/microsoft/mana/mana_en.c
> index d2f07e179e86..0a97bbdd958e 100644
> --- a/drivers/net/ethernet/microsoft/mana/mana_en.c
> +++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
> @@ -511,7 +511,7 @@ static u16 mana_select_queue(struct net_device *ndev,
> struct sk_buff *skb,
> }
>
> /* Release pre-allocated RX buffers */
> -static void mana_pre_dealloc_rxbufs(struct mana_port_context *mpc)
> +void mana_pre_dealloc_rxbufs(struct mana_port_context *mpc)
> {
> struct device *dev;
> int i;
> @@ -604,7 +604,7 @@ static void mana_get_rxbuf_cfg(int mtu, u32 *datasize,
> u32 *alloc_size,
> *datasize = mtu + ETH_HLEN;
> }
>
> -static int mana_pre_alloc_rxbufs(struct mana_port_context *mpc, int new_mtu)
> +int mana_pre_alloc_rxbufs(struct mana_port_context *mpc, int new_mtu)
> {
> struct device *dev;
> struct page *page;
> @@ -618,7 +618,7 @@ static int mana_pre_alloc_rxbufs(struct mana_port_context
> *mpc, int new_mtu)
>
> dev = mpc->ac->gdma_dev->gdma_context->dev;
>
> - num_rxb = mpc->num_queues * RX_BUFFERS_PER_QUEUE;
> + num_rxb = mpc->num_queues * mpc->rx_queue_size;
>
> WARN(mpc->rxbufs_pre, "mana rxbufs_pre exists\n");
> mpc->rxbufs_pre = kmalloc_array(num_rxb, sizeof(void *), GFP_KERNEL);
> @@ -1899,15 +1899,17 @@ static int mana_create_txq(struct mana_port_context
> *apc,
> return -ENOMEM;
>
> /* The minimum size of the WQE is 32 bytes, hence
> - * MAX_SEND_BUFFERS_PER_QUEUE represents the maximum number of WQEs
> + * apc->tx_queue_size represents the maximum number of WQEs
> * the SQ can store. This value is then used to size other queues
> * to prevent overflow.
> + * Also note that the txq_size is always going to be MANA_PAGE_ALIGNED,
> + * as min val of apc->tx_queue_size is 128 and that would make
> + * txq_size 128*32 = 4096 and the other higher values of
> apc->tx_queue_size
> + * are always power of two
> */
> - txq_size = MAX_SEND_BUFFERS_PER_QUEUE * 32;
> - BUILD_BUG_ON(!MANA_PAGE_ALIGNED(txq_size));
> + txq_size = apc->tx_queue_size * 32;
>
> - cq_size = MAX_SEND_BUFFERS_PER_QUEUE * COMP_ENTRY_SIZE;
> - cq_size = MANA_PAGE_ALIGN(cq_size);
> + cq_size = apc->tx_queue_size * COMP_ENTRY_SIZE;
>
> gc = gd->gdma_context;
>
> @@ -2145,10 +2147,11 @@ static int mana_push_wqe(struct mana_rxq *rxq)
>
> static int mana_create_page_pool(struct mana_rxq *rxq, struct gdma_context
> *gc)
> {
> + struct mana_port_context *mpc = netdev_priv(rxq->ndev);
> struct page_pool_params pprm = {};
> int ret;
>
> - pprm.pool_size = RX_BUFFERS_PER_QUEUE;
> + pprm.pool_size = mpc->rx_queue_size;
> pprm.nid = gc->numa_node;
> pprm.napi = &rxq->rx_cq.napi;
> pprm.netdev = rxq->ndev;
> @@ -2180,13 +2183,13 @@ static struct mana_rxq *mana_create_rxq(struct
> mana_port_context *apc,
>
> gc = gd->gdma_context;
>
> - rxq = kzalloc(struct_size(rxq, rx_oobs, RX_BUFFERS_PER_QUEUE),
> + rxq = kzalloc(struct_size(rxq, rx_oobs, apc->rx_queue_size),
> GFP_KERNEL);
> if (!rxq)
> return NULL;
>
> rxq->ndev = ndev;
> - rxq->num_rx_buf = RX_BUFFERS_PER_QUEUE;
> + rxq->num_rx_buf = apc->rx_queue_size;
> rxq->rxq_idx = rxq_idx;
> rxq->rxobj = INVALID_MANA_HANDLE;
>
> @@ -2734,6 +2737,8 @@ static int mana_probe_port(struct mana_context *ac, int
> port_idx,
> apc->ndev = ndev;
> apc->max_queues = gc->max_num_queues;
> apc->num_queues = gc->max_num_queues;
> + apc->tx_queue_size = DEF_TX_BUFFERS_PER_QUEUE;
> + apc->rx_queue_size = DEF_RX_BUFFERS_PER_QUEUE;
> apc->port_handle = INVALID_MANA_HANDLE;
> apc->pf_filter_handle = INVALID_MANA_HANDLE;
> apc->port_idx = port_idx;
> diff --git a/drivers/net/ethernet/microsoft/mana/mana_ethtool.c
> b/drivers/net/ethernet/microsoft/mana/mana_ethtool.c
> index 146d5db1792f..d6a35fbda447 100644
> --- a/drivers/net/ethernet/microsoft/mana/mana_ethtool.c
> +++ b/drivers/net/ethernet/microsoft/mana/mana_ethtool.c
> @@ -369,6 +369,78 @@ static int mana_set_channels(struct net_device *ndev,
> return err;
> }
>
> +static void mana_get_ringparam(struct net_device *ndev,
> + struct ethtool_ringparam *ring,
> + struct kernel_ethtool_ringparam *kernel_ring,
> + struct netlink_ext_ack *extack)
> +{
> + struct mana_port_context *apc = netdev_priv(ndev);
> +
> + ring->rx_pending = apc->rx_queue_size;
> + ring->tx_pending = apc->tx_queue_size;
> + ring->rx_max_pending = MAX_RX_BUFFERS_PER_QUEUE;
> + ring->tx_max_pending = MAX_TX_BUFFERS_PER_QUEUE;
> +}
> +
> +static int mana_set_ringparam(struct net_device *ndev,
> + struct ethtool_ringparam *ring,
> + struct kernel_ethtool_ringparam *kernel_ring,
> + struct netlink_ext_ack *extack)
> +{
> + struct mana_port_context *apc = netdev_priv(ndev);
> + u32 new_tx, new_rx;
> + u32 old_tx, old_rx;
> + int err;
> +
> + old_tx = apc->tx_queue_size;
> + old_rx = apc->rx_queue_size;
> +
> + if (ring->tx_pending < MIN_TX_BUFFERS_PER_QUEUE) {
> + NL_SET_ERR_MSG_FMT(extack, "tx:%d less than the min:%d",
> ring->tx_pending,
> + MIN_TX_BUFFERS_PER_QUEUE);
> + return -EINVAL;
> + }
> +
> + if (ring->rx_pending < MIN_RX_BUFFERS_PER_QUEUE) {
> + NL_SET_ERR_MSG_FMT(extack, "rx:%d less than the min:%d",
> ring->rx_pending,
> + MIN_RX_BUFFERS_PER_QUEUE);
> + return -EINVAL;
> + }
> +
> + new_rx = roundup_pow_of_two(ring->rx_pending);
> + new_tx = roundup_pow_of_two(ring->tx_pending);
> + netdev_info(ndev, "Using nearest power of 2 values for Txq:%d Rxq:%d\n",
> + new_tx, new_rx);
> +
> + /* pre-allocating new buffers to prevent failures in mana_attach()
> later */
> + apc->rx_queue_size = new_rx;
> + err = mana_pre_alloc_rxbufs(apc, ndev->mtu);
> + apc->rx_queue_size = old_rx;
> + if (err) {
> + netdev_err(ndev, "Insufficient memory for new allocations\n");
> + return err;
> + }
> +
> + err = mana_detach(ndev, false);
> + if (err) {
> + netdev_err(ndev, "mana_detach failed: %d\n", err);
> + goto out;
> + }
> +
> + apc->tx_queue_size = new_tx;
> + apc->rx_queue_size = new_rx;
> +
> + err = mana_attach(ndev);
> + if (err) {
> + netdev_err(ndev, "mana_attach failed: %d\n", err);
> + apc->tx_queue_size = old_tx;
> + apc->rx_queue_size = old_rx;
> + }
> +out:
> + mana_pre_dealloc_rxbufs(apc);
> + return err;
> +}
> +
> const struct ethtool_ops mana_ethtool_ops = {
> .get_ethtool_stats = mana_get_ethtool_stats,
> .get_sset_count = mana_get_sset_count,
> @@ -380,4 +452,6 @@ const struct ethtool_ops mana_ethtool_ops = {
> .set_rxfh = mana_set_rxfh,
> .get_channels = mana_get_channels,
> .set_channels = mana_set_channels,
> + .get_ringparam = mana_get_ringparam,
> + .set_ringparam = mana_set_ringparam,
> };
> diff --git a/include/net/mana/mana.h b/include/net/mana/mana.h
> index 6439fd8b437b..80a1e53471a6 100644
> --- a/include/net/mana/mana.h
> +++ b/include/net/mana/mana.h
> @@ -38,9 +38,21 @@ enum TRI_STATE {
>
> #define COMP_ENTRY_SIZE 64
>
> -#define RX_BUFFERS_PER_QUEUE 512
> +/* This Max value for RX buffers is derived from __alloc_page()'s max page
> + * allocation calculation. It allows maximum 2^(MAX_ORDER -1) pages. RX
> buffer
> + * size beyond this value gets rejected by __alloc_page() call.
> + */
> +#define MAX_RX_BUFFERS_PER_QUEUE 8192
> +#define DEF_RX_BUFFERS_PER_QUEUE 512
> +#define MIN_RX_BUFFERS_PER_QUEUE 128
>
> -#define MAX_SEND_BUFFERS_PER_QUEUE 256
> +/* This max value for TX buffers is derived as the maximum allocatable
> + * pages supported on host per guest through testing. TX buffer size beyond
> + * this value is rejected by the hardware.
> + */
> +#define MAX_TX_BUFFERS_PER_QUEUE 16384
> +#define DEF_TX_BUFFERS_PER_QUEUE 256
> +#define MIN_TX_BUFFERS_PER_QUEUE 128
>
> #define EQ_SIZE (8 * MANA_PAGE_SIZE)
>
> @@ -285,7 +297,7 @@ struct mana_recv_buf_oob {
> void *buf_va;
> bool from_pool; /* allocated from a page pool */
>
> - /* SGL of the buffer going to be sent has part of the work request. */
> + /* SGL of the buffer going to be sent as part of the work request. */
> u32 num_sge;
> struct gdma_sge sgl[MAX_RX_WQE_SGL_ENTRIES];
>
> @@ -437,6 +449,9 @@ struct mana_port_context {
> unsigned int max_queues;
> unsigned int num_queues;
>
> + unsigned int rx_queue_size;
> + unsigned int tx_queue_size;
> +
> mana_handle_t port_handle;
> mana_handle_t pf_filter_handle;
>
> @@ -472,6 +487,8 @@ struct bpf_prog *mana_xdp_get(struct mana_port_context
> *apc);
> void mana_chn_setxdp(struct mana_port_context *apc, struct bpf_prog *prog);
> int mana_bpf(struct net_device *ndev, struct netdev_bpf *bpf);
> void mana_query_gf_stats(struct mana_port_context *apc);
> +int mana_pre_alloc_rxbufs(struct mana_port_context *apc, int mtu);
> +void mana_pre_dealloc_rxbufs(struct mana_port_context *apc);
>
> extern const struct ethtool_ops mana_ethtool_ops;
>
> --
> 2.34.1
>
Reviewed-by: Saurabh Sengar <ssen...@linux.microsoft.com>
