[PATCH v4 06/11] vdpa/nfp: add the interrupt logic of vring relay

[Chaoyong He <chaoyong.he@corigine.com>]

From: Xinying Yu <xinying.yu@corigine.com>

Add the interrupt setup logic of vring relay.

The epoll fd is provided here so host can get the interrupt from device
on Rx direction, all other operations on vring relay are based on this.

Signed-off-by: Xinying Yu <xinying.yu@corigine.com>
Reviewed-by: Chaoyong He <chaoyong.he@corigine.com>
Reviewed-by: Long Wu <long.wu@corigine.com>
Reviewed-by: Peng Zhang <peng.zhang@corigine.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 drivers/vdpa/nfp/nfp_vdpa.c | 24 ++++++++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/drivers/vdpa/nfp/nfp_vdpa.c b/drivers/vdpa/nfp/nfp_vdpa.c
index 45092cb0af..1643ebbb8c 100644
--- a/drivers/vdpa/nfp/nfp_vdpa.c
+++ b/drivers/vdpa/nfp/nfp_vdpa.c
@@ -336,8 +336,10 @@ nfp_vdpa_stop(struct nfp_vdpa_dev *device)
 }
 
 static int
-nfp_vdpa_enable_vfio_intr(struct nfp_vdpa_dev *device)
+nfp_vdpa_enable_vfio_intr(struct nfp_vdpa_dev *device,
+		bool relay)
 {
+	int fd;
 	int ret;
 	uint16_t i;
 	int *fd_ptr;
@@ -366,6 +368,19 @@ nfp_vdpa_enable_vfio_intr(struct nfp_vdpa_dev *device)
 		fd_ptr[RTE_INTR_VEC_RXTX_OFFSET + i] = vring.callfd;
 	}
 
+	if (relay) {
+		for (i = 0; i < nr_vring; i += 2) {
+			fd = eventfd(0, EFD_NONBLOCK | EFD_CLOEXEC);
+			if (fd < 0) {
+				DRV_VDPA_LOG(ERR, "Can't setup eventfd");
+				return -EINVAL;
+			}
+
+			device->intr_fd[i] = fd;
+			fd_ptr[RTE_INTR_VEC_RXTX_OFFSET + i] = fd;
+		}
+	}
+
 	ret = ioctl(device->vfio_dev_fd, VFIO_DEVICE_SET_IRQS, irq_set);
 	if (ret != 0) {
 		DRV_VDPA_LOG(ERR, "Error enabling MSI-X interrupts.");
@@ -556,7 +571,7 @@ update_datapath(struct nfp_vdpa_dev *device)
 		if (ret != 0)
 			goto unlock_exit;
 
-		ret = nfp_vdpa_enable_vfio_intr(device);
+		ret = nfp_vdpa_enable_vfio_intr(device, false);
 		if (ret != 0)
 			goto dma_map_rollback;
 
@@ -619,6 +634,11 @@ nfp_vdpa_sw_fallback(struct nfp_vdpa_dev *device)
 		goto error;
 	}
 
+	/* Setup interrupt for vring relay */
+	ret = nfp_vdpa_enable_vfio_intr(device, true);
+	if (ret != 0)
+		goto error;
+
 	device->hw.sw_fallback_running = true;
 
 	return 0;
-- 
2.39.1