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From:   Eric Auger <eric.auger@redhat.com>
To:     eric.auger.pro@gmail.com, eric.auger@redhat.com,
        iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
        kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu, joro@8bytes.org,
        alex.williamson@redhat.com, jacob.jun.pan@linux.intel.com,
        yi.l.liu@intel.com, jean-philippe.brucker@arm.com,
        will.deacon@arm.com, robin.murphy@arm.com
Cc:     marc.zyngier@arm.com, peter.maydell@linaro.org,
        zhangfei.gao@gmail.com
Subject: [PATCH v10 10/11] vfio/pci: Register and allow DMA FAULT IRQ signaling
Date:   Fri, 20 Mar 2020 17:19:10 +0100
Message-Id: <20200320161911.27494-11-eric.auger@redhat.com>
In-Reply-To: <20200320161911.27494-1-eric.auger@redhat.com>
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Register the VFIO_IRQ_TYPE_NESTED/VFIO_IRQ_SUBTYPE_DMA_FAULT
IRQ that allows to signal a nested mode DMA fault.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
---
 drivers/vfio/pci/vfio_pci.c | 22 ++++++++++++++++++++--
 1 file changed, 20 insertions(+), 2 deletions(-)

diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index ca13067e4718..70e3a31da9f0 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -346,7 +346,7 @@ int vfio_pci_iommu_dev_fault_handler(struct iommu_fau=
lt *fault, void *data)
 	struct iommu_fault *new =3D
 		(struct iommu_fault *)(vdev->fault_pages + reg->offset +
 			reg->head * reg->entry_size);
-	int head, tail, size;
+	int head, tail, size, ext_irq_index;
 	int ret =3D 0;
=20
 	if (fault->type !=3D IOMMU_FAULT_DMA_UNRECOV)
@@ -367,7 +367,19 @@ int vfio_pci_iommu_dev_fault_handler(struct iommu_fa=
ult *fault, void *data)
 	reg->head =3D (head + 1) % size;
 unlock:
 	mutex_unlock(&vdev->fault_queue_lock);
-	return ret;
+	if (ret)
+		return ret;
+
+	ext_irq_index =3D vfio_pci_get_ext_irq_index(vdev, VFIO_IRQ_TYPE_NESTED=
,
+						   VFIO_IRQ_SUBTYPE_DMA_FAULT);
+	if (ext_irq_index < 0)
+		return -EINVAL;
+
+	mutex_lock(&vdev->igate);
+	if (vdev->ext_irqs[ext_irq_index].trigger)
+		eventfd_signal(vdev->ext_irqs[ext_irq_index].trigger, 1);
+	mutex_unlock(&vdev->igate);
+	return 0;
 }
=20
 #define DMA_FAULT_RING_LENGTH 512
@@ -520,6 +532,12 @@ static int vfio_pci_enable(struct vfio_pci_device *v=
dev)
 	if (ret)
 		goto disable_exit;
=20
+	ret =3D vfio_pci_register_irq(vdev, VFIO_IRQ_TYPE_NESTED,
+				    VFIO_IRQ_SUBTYPE_DMA_FAULT,
+				    VFIO_IRQ_INFO_EVENTFD);
+	if (ret)
+		goto disable_exit;
+
 	vfio_pci_probe_mmaps(vdev);
=20
 	return 0;
--=20
2.20.1