[PATCH v2 1/5] eal/linux: add interrupt type for vdev

[Jianfeng Tan <jianfeng.tan@intel.com>]

A new interrupt type, RTE_INTR_HANDLE_VDEV, is added to support lsc and rxq
interrupt for vdev.

For lsc interrupt, except from original EPOLLIN events, we also listen for
socket peer closed connection event (EPOLLRDHUP and EPOLLHUP).

For rxq interrupt, add a precondition to avoid invoking any vfio and uio
code.

Signed-off-by: Jianfeng Tan <jianfeng.tan@intel.com>
---
 lib/librte_eal/linuxapp/eal/eal_interrupts.c       | 30 +++++++++++++++++++---
 .../linuxapp/eal/include/exec-env/rte_interrupts.h |  5 ++--
 2 files changed, 30 insertions(+), 5 deletions(-)

diff --git a/lib/librte_eal/linuxapp/eal/eal_interrupts.c b/lib/librte_eal/linuxapp/eal/eal_interrupts.c
index 92a19cb..5cf7bbc 100644
--- a/lib/librte_eal/linuxapp/eal/eal_interrupts.c
+++ b/lib/librte_eal/linuxapp/eal/eal_interrupts.c
@@ -46,6 +46,7 @@
 #include <sys/ioctl.h>
 #include <sys/eventfd.h>
 #include <assert.h>
+#include <stdbool.h>
 
 #include <rte_common.h>
 #include <rte_interrupts.h>
@@ -583,6 +584,9 @@ rte_intr_callback_unregister(const struct rte_intr_handle *intr_handle,
 int
 rte_intr_enable(const struct rte_intr_handle *intr_handle)
 {
+	if (intr_handle && intr_handle->type == RTE_INTR_HANDLE_VDEV)
+		return 0;
+
 	if (!intr_handle || intr_handle->fd < 0 || intr_handle->uio_cfg_fd < 0)
 		return -1;
 
@@ -627,6 +631,9 @@ rte_intr_enable(const struct rte_intr_handle *intr_handle)
 int
 rte_intr_disable(const struct rte_intr_handle *intr_handle)
 {
+	if (intr_handle && intr_handle->type == RTE_INTR_HANDLE_VDEV)
+		return 0;
+
 	if (!intr_handle || intr_handle->fd < 0 || intr_handle->uio_cfg_fd < 0)
 		return -1;
 
@@ -671,6 +678,7 @@ rte_intr_disable(const struct rte_intr_handle *intr_handle)
 static int
 eal_intr_process_interrupts(struct epoll_event *events, int nfds)
 {
+	bool call = false;
 	int n, bytes_read;
 	struct rte_intr_source *src;
 	struct rte_intr_callback *cb;
@@ -719,13 +727,18 @@ eal_intr_process_interrupts(struct epoll_event *events, int nfds)
 			bytes_read = sizeof(buf.vfio_intr_count);
 			break;
 #endif
+		case RTE_INTR_HANDLE_VDEV:
 		case RTE_INTR_HANDLE_EXT:
+			bytes_read = 0;
+			call = true;
+			break;
+
 		default:
 			bytes_read = 1;
 			break;
 		}
 
-		if (src->intr_handle.type != RTE_INTR_HANDLE_EXT) {
+		if (bytes_read > 0) {
 			/**
 			 * read out to clear the ready-to-be-read flag
 			 * for epoll_wait.
@@ -742,12 +755,14 @@ eal_intr_process_interrupts(struct epoll_event *events, int nfds)
 			} else if (bytes_read == 0)
 				RTE_LOG(ERR, EAL, "Read nothing from file "
 					"descriptor %d\n", events[n].data.fd);
+			else
+				call = true;
 		}
 
 		/* grab a lock, again to call callbacks and update status. */
 		rte_spinlock_lock(&intr_lock);
 
-		if (bytes_read > 0) {
+		if (call) {
 
 			/* Finally, call all callbacks. */
 			TAILQ_FOREACH(cb, &src->callbacks, next) {
@@ -858,7 +873,7 @@ eal_intr_thread_main(__rte_unused void *arg)
 		TAILQ_FOREACH(src, &intr_sources, next) {
 			if (src->callbacks.tqh_first == NULL)
 				continue; /* skip those with no callbacks */
-			ev.events = EPOLLIN | EPOLLPRI;
+			ev.events = EPOLLIN | EPOLLPRI | EPOLLRDHUP | EPOLLHUP;
 			ev.data.fd = src->intr_handle.fd;
 
 			/**
@@ -939,6 +954,12 @@ eal_intr_proc_rxtx_intr(int fd, const struct rte_intr_handle *intr_handle)
 		bytes_read = sizeof(buf.vfio_intr_count);
 		break;
 #endif
+	case RTE_INTR_HANDLE_VDEV:
+		/* for vdev, fd points to:
+		 * a. eventfd which does not need to read out;
+		 * b. datapath fd which needs PMD to read out.
+		 */
+		return;
 	default:
 		bytes_read = 1;
 		RTE_LOG(INFO, EAL, "unexpected intr type\n");
@@ -1244,5 +1265,8 @@ rte_intr_cap_multiple(struct rte_intr_handle *intr_handle)
 	if (intr_handle->type == RTE_INTR_HANDLE_VFIO_MSIX)
 		return 1;
 
+	if (intr_handle->type == RTE_INTR_HANDLE_VDEV)
+		return 1;
+
 	return 0;
 }
diff --git a/lib/librte_eal/linuxapp/eal/include/exec-env/rte_interrupts.h b/lib/librte_eal/linuxapp/eal/include/exec-env/rte_interrupts.h
index d459bf4..b8ee1de 100644
--- a/lib/librte_eal/linuxapp/eal/include/exec-env/rte_interrupts.h
+++ b/lib/librte_eal/linuxapp/eal/include/exec-env/rte_interrupts.h
@@ -49,8 +49,9 @@ enum rte_intr_handle_type {
 	RTE_INTR_HANDLE_VFIO_LEGACY,  /**< vfio device handle (legacy) */
 	RTE_INTR_HANDLE_VFIO_MSI,     /**< vfio device handle (MSI) */
 	RTE_INTR_HANDLE_VFIO_MSIX,    /**< vfio device handle (MSIX) */
-	RTE_INTR_HANDLE_ALARM,    /**< alarm handle */
-	RTE_INTR_HANDLE_EXT, /**< external handler */
+	RTE_INTR_HANDLE_ALARM,        /**< alarm handle */
+	RTE_INTR_HANDLE_EXT,          /**< external handler */
+	RTE_INTR_HANDLE_VDEV,         /**< virtual device */
 	RTE_INTR_HANDLE_MAX
 };
 
-- 
2.7.4