Hi,
The patch looks globally fine to me.
I'll inline just one comment.
Best regards,
Pascal
On 20/11/2017 14:59, Moti Haimovsky wrote:
> This patch adds support for registering and waiting for Rx interrupts.
> This allows applications to wait for Rx events from the PMD using the
> DPDK rte_epoll subsystem.
>
> Signed-off-by: Moti Haimovsky <mo...@mellanox.com>
> ---
> doc/guides/nics/features/tap.ini | 1 +
> drivers/net/tap/Makefile | 1 +
> drivers/net/tap/rte_eth_tap.c | 17 ++++-
> drivers/net/tap/rte_eth_tap.h | 4 ++
> drivers/net/tap/tap_intr.c | 147
> +++++++++++++++++++++++++++++++++++++++
> 5 files changed, 169 insertions(+), 1 deletion(-)
> create mode 100644 drivers/net/tap/tap_intr.c
>
> diff --git a/doc/guides/nics/features/tap.ini
> b/doc/guides/nics/features/tap.ini
> index f0e893d..8bc5187 100644
> --- a/doc/guides/nics/features/tap.ini
> +++ b/doc/guides/nics/features/tap.ini
> @@ -7,6 +7,7 @@
> Speed capabilities = P
> Link status = Y
> Link status event = Y
> +Rx interrupt = Y
> Jumbo frame = Y
> Promiscuous mode = Y
> Allmulticast mode = Y
> diff --git a/drivers/net/tap/Makefile b/drivers/net/tap/Makefile
> index 405b49e..6636b77 100644
> --- a/drivers/net/tap/Makefile
> +++ b/drivers/net/tap/Makefile
> @@ -54,6 +54,7 @@ SRCS-$(CONFIG_RTE_LIBRTE_PMD_TAP) += rte_eth_tap.c
> SRCS-$(CONFIG_RTE_LIBRTE_PMD_TAP) += tap_flow.c
> SRCS-$(CONFIG_RTE_LIBRTE_PMD_TAP) += tap_netlink.c
> SRCS-$(CONFIG_RTE_LIBRTE_PMD_TAP) += tap_tcmsgs.c
> +SRCS-$(CONFIG_RTE_LIBRTE_PMD_TAP) += tap_intr.c
>
> include $(RTE_SDK)/mk/rte.lib.mk
>
> diff --git a/drivers/net/tap/rte_eth_tap.c b/drivers/net/tap/rte_eth_tap.c
> index 6b27679..7e6de68 100644
> --- a/drivers/net/tap/rte_eth_tap.c
> +++ b/drivers/net/tap/rte_eth_tap.c
> @@ -1127,7 +1127,7 @@ enum ioctl_mode {
> }
>
> static int
> -tap_intr_handle_set(struct rte_eth_dev *dev, int set)
> +tap_lsc_intr_handle_set(struct rte_eth_dev *dev, int set)
> {
> struct pmd_internals *pmd = dev->data->dev_private;
>
> @@ -1152,6 +1152,20 @@ enum ioctl_mode {
> tap_dev_intr_handler, dev);
> }
>
> +static int
> +tap_intr_handle_set(struct rte_eth_dev *dev, int set)
> +{
> + int err;
> +
> + err = tap_lsc_intr_handle_set(dev, set);
> + if (err)
> + return err;
> + err = tap_rx_intr_vec_set(dev, set);
> + if (err && set)
> + tap_lsc_intr_handle_set(dev, 0);
> + return err;
> +}
> +
> static const uint32_t*
> tap_dev_supported_ptypes_get(struct rte_eth_dev *dev __rte_unused)
> {
> @@ -1284,6 +1298,7 @@ enum ioctl_mode {
>
> pmd->intr_handle.type = RTE_INTR_HANDLE_EXT;
> pmd->intr_handle.fd = -1;
> + dev->intr_handle = &pmd->intr_handle;
>
> /* Presetup the fds to -1 as being not valid */
> for (i = 0; i < RTE_PMD_TAP_MAX_QUEUES; i++) {
> diff --git a/drivers/net/tap/rte_eth_tap.h b/drivers/net/tap/rte_eth_tap.h
> index 829f32f..fccc4b8 100644
> --- a/drivers/net/tap/rte_eth_tap.h
> +++ b/drivers/net/tap/rte_eth_tap.h
> @@ -98,4 +98,8 @@ struct pmd_internals {
> struct rte_intr_handle intr_handle; /* LSC interrupt handle. */
> };
>
> +/* tap_intr.c */
> +
> +int tap_rx_intr_vec_set(struct rte_eth_dev *dev, int set);
> +
> #endif /* _RTE_ETH_TAP_H_ */
> diff --git a/drivers/net/tap/tap_intr.c b/drivers/net/tap/tap_intr.c
> new file mode 100644
> index 0000000..ef25ca6
> --- /dev/null
> +++ b/drivers/net/tap/tap_intr.c
> @@ -0,0 +1,147 @@
> +/*-
> + * BSD LICENSE
> + *
> + * Copyright 2017 Mellanox
> + *
> + * Redistribution and use in source and binary forms, with or without
> + * modification, are permitted provided that the following conditions
> + * are met:
> + *
> + * * Redistributions of source code must retain the above copyright
> + * notice, this list of conditions and the following disclaimer.
> + * * Redistributions in binary form must reproduce the above copyright
> + * notice, this list of conditions and the following disclaimer in
> + * the documentation and/or other materials provided with the
> + * distribution.
> + * * Neither the name of the copyright holder nor the names of its
> + * contributors may be used to endorse or promote products derived
> + * from this software without specific prior written permission.
> + *
> + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
> + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
> + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
> + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
> + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
> + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
> + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
> + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
> + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
> + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
> + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
> + */
> +
> +/**
> + * @file
> + * Interrupts handling for tap driver.
> + */
> +
> +#include <assert.h>
> +#include <errno.h>
> +#include <fcntl.h>
> +#include <signal.h>
> +#include <stdint.h>
> +#include <stdlib.h>
> +#include <unistd.h>
> +
> +#include <rte_eth_tap.h>
> +#include <rte_errno.h>
> +#include <rte_interrupts.h>
> +
> +
> +/**
> + * Unregister Rx interrupts free the queue interrupt vector.
> + *
> + * @param dev
> + * Pointer to the tap rte_eth_dev structure.
> + */
> +static void
> +tap_rx_intr_vec_uninstall(struct rte_eth_dev *dev)
> +{
> + struct pmd_internals *pmd = dev->data->dev_private;
> + struct rte_intr_handle *intr_handle = &pmd->intr_handle;
> +
> + rte_intr_free_epoll_fd(intr_handle);
> + free(intr_handle->intr_vec);
> + intr_handle->intr_vec = NULL;
> + intr_handle->nb_efd = 0;
> +}
> +
> +/**
> + * Allocate Rx queue interrupt vector and register Rx interrupts.
> + *
> + * @param dev
> + * Pointer to the tap rte_eth_dev device structure.
> + *
> + * @return
> + * 0 on success, negative errno value otherwise and rte_errno is set.
> + */
> +static int
> +tap_rx_intr_vec_install(struct rte_eth_dev *dev)
> +{
> + struct pmd_internals *pmd = dev->data->dev_private;
> + unsigned int rxqs_n = pmd->dev->data->nb_rx_queues;
> + struct rte_intr_handle *intr_handle = &pmd->intr_handle;
> + unsigned int n = RTE_MIN(rxqs_n, (uint32_t)RTE_MAX_RXTX_INTR_VEC_ID);
> + unsigned int i;
> + unsigned int count = 0;
> +
> + if (!dev->data->dev_conf.intr_conf.rxq)
> + return 0;
> + intr_handle->intr_vec = malloc(sizeof(intr_handle->intr_vec[rxqs_n]));
> + if (intr_handle->intr_vec == NULL) {
> + rte_errno = ENOMEM;
> + RTE_LOG(ERR, PMD,
> + "failed to allocate memory for interrupt vector,"
> + " Rx interrupts will not be supported");
> + return -rte_errno;
> + }
> + for (i = 0; i < n; i++) {
> + struct rx_queue *rxq = pmd->dev->data->rx_queues[i];
> +
> + /* Skip queues that cannot request interrupts. */
> + if (!rxq || (rxq->fd <= 0)) {
> + /* Use invalid intr_vec[] index to disable entry. */
> + intr_handle->intr_vec[i] =
> + RTE_INTR_VEC_RXTX_OFFSET +
> + RTE_MAX_RXTX_INTR_VEC_ID;
> + continue;
>
If I'm not mistaken, the following if (count >=...) will never be reached.
count starts from 0, and can only be increased at most n - 1 times.
n being min(rxqsg, RTE_MAX_RXTX_INTR_VEC_ID), it won't exceed the max.
I would remove that little condition.
> + if (count >= RTE_MAX_RXTX_INTR_VEC_ID) {
> + rte_errno = E2BIG;
> + RTE_LOG(ERR, PMD,
> + "too many Rx queues for interrupt vector size"
> + " (%d), Rx interrupts cannot be enabled",
> + RTE_MAX_RXTX_INTR_VEC_ID);
> + tap_rx_intr_vec_uninstall(dev);
> + return -rte_errno;
> + }
> + intr_handle->intr_vec[i] = RTE_INTR_VEC_RXTX_OFFSET + count;
> + intr_handle->efds[count] = rxq->fd;
> + count++;
> + }
> + if (!count)
> + tap_rx_intr_vec_uninstall(dev);
> + else
> + intr_handle->nb_efd = count;
> + return 0;
> +}
> +
> +/**
> + * Register or unregister the Rx interrupts.
> + *
> + * @param dev
> + * Pointer to the tap rte_eth_dev device structure.
> + * @param set
> + * should the operation be register or unregister the interrupts.
> + *
> + * @return
> + * 0 on success, negative errno value otherwise and rte_errno is set.
> + */
> +int
> +tap_rx_intr_vec_set(struct rte_eth_dev *dev, int set)
> +{
> + tap_rx_intr_vec_uninstall(dev);
> + if (set)
> + return tap_rx_intr_vec_install(dev);
> + return 0;
> +}
