[PATCH v5 12/14] vfio/mdev: idxd: add irq bypass for IMS vectors

[Dave Jiang <dave.jiang@xxxxxxxxx>]

Add support to bypass host for IMS interrupts configured for the guest.

Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx>
---
 drivers/vfio/mdev/Kconfig     |    1 +
 drivers/vfio/mdev/idxd/mdev.c |   17 +++++++++++++++--
 drivers/vfio/mdev/idxd/mdev.h |    1 +
 3 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/drivers/vfio/mdev/Kconfig b/drivers/vfio/mdev/Kconfig
index e9540e43d1f1..ab0a6f0930bc 100644
--- a/drivers/vfio/mdev/Kconfig
+++ b/drivers/vfio/mdev/Kconfig
@@ -22,6 +22,7 @@ config VFIO_MDEV_IDXD
 	depends on VFIO && VFIO_MDEV && X86_64
 	select AUXILIARY_BUS
 	select IMS_MSI_ARRAY
+	select IRQ_BYPASS_MANAGER
 	default n
 	help
 	  VFIO based mediated device driver for Intel Accelerator Devices driver.
diff --git a/drivers/vfio/mdev/idxd/mdev.c b/drivers/vfio/mdev/idxd/mdev.c
index 8a4af882a47f..d59920f78109 100644
--- a/drivers/vfio/mdev/idxd/mdev.c
+++ b/drivers/vfio/mdev/idxd/mdev.c
@@ -616,9 +616,13 @@ static int msix_trigger_unregister(struct vdcm_idxd *vidxd, int index)
 
 	dev_dbg(dev, "disable MSIX trigger %d\n", index);
 	if (index) {
+		struct irq_bypass_producer *producer;
 		u32 auxval;
 
+		producer = &vidxd->vdev.producer[index];
+		irq_bypass_unregister_producer(producer);
 		irq_entry = &vidxd->irq_entries[index];
+
 		if (irq_entry->irq_set) {
 			free_irq(irq_entry->irq, irq_entry);
 			irq_entry->irq_set = false;
@@ -654,9 +658,10 @@ static int msix_trigger_register(struct vdcm_idxd *vidxd, u32 fd, int index)
 	}
 
 	if (index) {
-		u32 pasid;
-		u32 auxval;
+		struct irq_bypass_producer *producer;
+		u32 pasid, auxval;
 
+		producer = &vidxd->vdev.producer[index];
 		irq_entry = &vidxd->irq_entries[index];
 		rc = idxd_mdev_get_pasid(mdev, &pasid);
 		if (rc < 0)
@@ -682,6 +687,14 @@ static int msix_trigger_register(struct vdcm_idxd *vidxd, u32 fd, int index)
 			irq_set_auxdata(irq_entry->irq, IMS_AUXDATA_CONTROL_WORD, auxval);
 			return rc;
 		}
+
+		producer->token = trigger;
+		producer->irq = irq_entry->irq;
+		rc = irq_bypass_register_producer(producer);
+		if (unlikely(rc))
+			dev_info(dev, "irq bypass producer (token %p) registration failed: %d\n",
+				 producer->token, rc);
+
 		irq_entry->irq_set = true;
 	}
 
diff --git a/drivers/vfio/mdev/idxd/mdev.h b/drivers/vfio/mdev/idxd/mdev.h
index 8421b4962ac7..1f867de416e7 100644
--- a/drivers/vfio/mdev/idxd/mdev.h
+++ b/drivers/vfio/mdev/idxd/mdev.h
@@ -45,6 +45,7 @@ struct idxd_vdev {
 	struct mdev_device *mdev;
 	struct vfio_group *vfio_group;
 	struct eventfd_ctx *msix_trigger[VIDXD_MAX_MSIX_ENTRIES];
+	struct irq_bypass_producer producer[VIDXD_MAX_MSIX_ENTRIES];
 };
 
 struct vdcm_idxd {