From: Robin Murphy <robin.murphy@arm.com>
To: alex.williamson@redhat.com
Cc: cohuck@redhat.com, iommu@lists.linux-foundation.org,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] vfio: Stop using iommu_present()
Date: Tue, 5 Apr 2022 13:11:54 +0100 [thread overview]
Message-ID: <537103bbd7246574f37f2c88704d7824a3a889f2.1649160714.git.robin.murphy@arm.com> (raw)
IOMMU groups have been mandatory for some time now, so a device without
one is necessarily a device without any usable IOMMU, therefore the
iommu_present() check is redundant (or at best unhelpful).
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---
drivers/vfio/vfio.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index a4555014bd1e..7b0a7b85e77e 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -745,11 +745,11 @@ static struct vfio_group *vfio_group_find_or_alloc(struct device *dev)
iommu_group = iommu_group_get(dev);
#ifdef CONFIG_VFIO_NOIOMMU
- if (!iommu_group && noiommu && !iommu_present(dev->bus)) {
+ if (!iommu_group && noiommu) {
/*
* With noiommu enabled, create an IOMMU group for devices that
- * don't already have one and don't have an iommu_ops on their
- * bus. Taint the kernel because we're about to give a DMA
+ * don't already have one, implying no IOMMU hardware/driver
+ * exists. Taint the kernel because we're about to give a DMA
* capable device to a user without IOMMU protection.
*/
group = vfio_noiommu_group_alloc(dev, VFIO_NO_IOMMU);
--
2.28.0.dirty
next reply other threads:[~2022-04-05 20:57 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-05 12:11 Robin Murphy [this message]
2022-04-05 19:04 ` Jason Gunthorpe
2022-05-12 18:21 ` Alex Williamson
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