Subject: [PATCH 4/7] vDPA/ifcvf: implement shared irq handlers for vqs

From: Zhu Lingshan <[email-masked]>
Date: Mon, 10 Jan 2022 13:19:44 +0800

It has observed that a device may fail to alloc enough vectors on
some platforms, e.g., requires 16 vectors, but only 2 or 4 vector
slots allocated. The virt queues have to share a vector/irq under
such circumstances.

This irq handlers has to kick every queue because it is not
possible to tell which queue triggers the interrupt.

Signed-off-by: Zhu Lingshan <[email-masked]>
---
 drivers/vdpa/ifcvf/ifcvf_main.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/drivers/vdpa/ifcvf/ifcvf_main.c b/drivers/vdpa/ifcvf/ifcvf_main.c
index 64fc78eaa1a9..19e1d1cd71a3 100644
--- a/drivers/vdpa/ifcvf/ifcvf_main.c
+++ b/drivers/vdpa/ifcvf/ifcvf_main.c
@@ -37,6 +37,21 @@ static irqreturn_t ifcvf_intr_handler(int irq, void *arg)
 	return IRQ_HANDLED;
 }
 
+static irqreturn_t ifcvf_shared_intr_handler(int irq, void *arg)
+{
+	struct ifcvf_hw *vf = arg;
+	struct vring_info *vring;
+	int i;
+
+	for (i = 0; i < vf->nr_vring; i++) {
+		vring = &vf->vring[i];
+		if (vring->cb.callback)
+			vf->vring->cb.callback(vring->cb.private);
+	}
+
+	return IRQ_HANDLED;
+}
+
 static void ifcvf_free_irq_vectors(void *data)
 {
 	pci_free_irq_vectors(data);
-- 
2.27.0