| Message ID | 1518189413-2761-3-git-send-email-geert+renesas@glider.be (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c index 2bc3705a99bd2f1a..7736c3fbe468a3da 100644 --- a/drivers/vfio/vfio.c +++ b/drivers/vfio/vfio.c @@ -129,9 +129,13 @@ struct iommu_group *vfio_iommu_group_get(struct device *dev) * bus. We set iommudata simply to be able to identify these groups * as special use and for reclamation later. */ - if (group || !noiommu || iommu_present(dev->bus)) + if (group || !noiommu) return group; + if (iommu_present(dev->bus)) + dev_warn(dev, "iommu present (%ps), ignoring\n", + dev->bus->iommu_ops); + group = iommu_group_alloc(); if (IS_ERR(group)) return NULL;
Allow use of the No-IOMMU mode even if a real IOMMU is present. This is useful in case the device is not part of an actual IOMMU group. Not-Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> --- Question: - Some devices (e.g. rcar-gpio) don't use DMA, so why do they need an IOMMU group? - Even devices using DMA may do so using a separate DMAC module, pointed to by "dmas" DT properties (e.g. sh-sci), hence they may be not part of an IOMMU group. - How to know which devices do DMA? --- drivers/vfio/vfio.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)