[dpdk-dev] [PATCH 2/3] vfio: Added vfio req interrupt support

[Harpal Singh <harpal.sd@samsung.com>]

From: Harpal Singh <harpal.sd@samsung.com>

This patch will add support for req interrupt which will be used
by vfio kernel module to request user space to release allocated resources.
It will provide addtional mechanism in user space to get system notification
about when to release vfio resources.

Signed-off-by: Harpal Singh <harpal.sd@samsung.com>
---
 lib/librte_eal/linuxapp/eal/eal_interrupts.c       | 67 ++++++++++++++++++++++
 .../linuxapp/eal/include/exec-env/rte_interrupts.h |  1 +
 2 files changed, 68 insertions(+)

diff --git a/lib/librte_eal/linuxapp/eal/eal_interrupts.c b/lib/librte_eal/linuxapp/eal/eal_interrupts.c
index 3f87875..6aca45f 100644
--- a/lib/librte_eal/linuxapp/eal/eal_interrupts.c
+++ b/lib/librte_eal/linuxapp/eal/eal_interrupts.c
@@ -346,6 +346,63 @@ vfio_disable_msix(struct rte_intr_handle *intr_handle) {
 
 	return ret;
 }
+
+/* enable req interrupts */
+static int
+vfio_enable_req(struct rte_intr_handle *intr_handle) {
+	struct vfio_irq_set *irq_set;
+	char irq_set_buf[IRQ_SET_BUF_LEN];
+	int len, ret =0;
+	int *fd_ptr;
+	len = sizeof(irq_set_buf);
+
+	/* enable REQx */
+	irq_set = (struct vfio_irq_set *) irq_set_buf;
+	irq_set->argsz = len;
+	irq_set->count = 1;
+	irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD | VFIO_IRQ_SET_ACTION_TRIGGER;
+	irq_set->index = VFIO_PCI_REQ_IRQ_INDEX;
+	irq_set->start = 0;
+	fd_ptr = (int *) &irq_set->data;
+	*fd_ptr = intr_handle->fd;
+	ret = ioctl(intr_handle->vfio_dev_fd, VFIO_DEVICE_SET_IRQS, irq_set);
+
+	if (ret) {
+		RTE_LOG(ERR, EAL, "Error enabling Req interrupts for fd %d\n",
+						intr_handle->fd);
+		return -1;
+	}
+
+	return ret;
+}
+
+/* disable req interrupts */
+static int
+vfio_disable_req(struct rte_intr_handle *intr_handle) {
+	struct vfio_irq_set *irq_set;
+	char irq_set_buf[IRQ_SET_BUF_LEN];
+	int len, ret;
+	int *fd_ptr;
+	len = sizeof(irq_set_buf);
+
+	/* mask interrupts before disabling */
+	irq_set = (struct vfio_irq_set *) irq_set_buf;
+	irq_set->argsz = len;
+	irq_set->count = 1;
+	irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD | VFIO_IRQ_SET_ACTION_TRIGGER;
+	irq_set->index = VFIO_PCI_REQ_IRQ_INDEX;
+	irq_set->start = 0;
+	fd_ptr = (int *) &irq_set->data;
+	*fd_ptr = -1;
+	ret = ioctl(intr_handle->vfio_dev_fd, VFIO_DEVICE_SET_IRQS, irq_set);
+
+	if (ret) {
+		RTE_LOG(ERR, EAL, "Error disableing Req interrupts for fd %d\n",
+						intr_handle->fd);
+		return -1;
+	}
+	return 0;
+}
 #endif
 
 static int
@@ -592,6 +649,11 @@ rte_intr_enable(struct rte_intr_handle *intr_handle)
 		if (vfio_enable_intx(intr_handle))
 			return -1;
 		break;
+
+	case RTE_INTR_HANDLE_VFIO_REQ:
+		if (vfio_enable_req(intr_handle))
+			return -1;
+		break;
 #endif
 	/* unknown handle type */
 	default:
@@ -636,6 +698,10 @@ rte_intr_disable(struct rte_intr_handle *intr_handle)
 		if (vfio_disable_intx(intr_handle))
 			return -1;
 		break;
+	case RTE_INTR_HANDLE_VFIO_REQ:
+		if (vfio_disable_req(intr_handle))
+			return -1;
+		break;
 #endif
 	/* unknown handle type */
 	default:
@@ -696,6 +762,7 @@ eal_intr_process_interrupts(struct epoll_event *events, int nfds)
 		case RTE_INTR_HANDLE_VFIO_MSIX:
 		case RTE_INTR_HANDLE_VFIO_MSI:
 		case RTE_INTR_HANDLE_VFIO_LEGACY:
+		case RTE_INTR_HANDLE_VFIO_REQ:
 			bytes_read = sizeof(buf.vfio_intr_count);
 			break;
 #endif
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 b05f4c8..e9c4729 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
@@ -48,6 +48,7 @@ enum rte_intr_handle_type {
 	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_VFIO_REQ, /**< request device handle */
 	RTE_INTR_HANDLE_MAX
 };
 
-- 
1.9.1