From: Jacob Pan <jacob.pan@linux.microsoft.com>
To: linux-kernel@vger.kernel.org,
"iommu@lists.linux.dev" <iommu@lists.linux.dev>,
Jason Gunthorpe <jgg@nvidia.com>,
"Tian, Kevin" <kevin.tian@intel.com>,
Alex Williamson <alex@shazbot.org>
Cc: Jacob Pan <jacob.pan@linux.microsoft.com>
Subject: [PATCH] iommufd: vfio compatibility extension check for noiommu mode
Date: Fri, 13 Feb 2026 10:36:36 -0800 [thread overview]
Message-ID: <20260213183636.3340-1-jacob.pan@linux.microsoft.com> (raw)
VFIO_CHECK_EXTENSION should return false for TYPE1_IOMMU variants when
in NO-IOMMU mode and IOMMUFD compat container is set. This change makes
the behavior match VFIO_CONTAINER in noiommu mode. It also prevents
userspace from incorrectly attempting to use TYPE1 IOMMU operations
in a no-iommu context.
Fixes: d624d6652a65 ("iommufd: vfio container FD ioctl compatibility")
Signed-off-by: Jacob Pan <jacob.pan@linux.microsoft.com>
---
drivers/iommu/iommufd/vfio_compat.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/iommu/iommufd/vfio_compat.c b/drivers/iommu/iommufd/vfio_compat.c
index a258ee2f4579..acb48cdd3b00 100644
--- a/drivers/iommu/iommufd/vfio_compat.c
+++ b/drivers/iommu/iommufd/vfio_compat.c
@@ -283,7 +283,7 @@ static int iommufd_vfio_check_extension(struct iommufd_ctx *ictx,
case VFIO_TYPE1_IOMMU:
case VFIO_TYPE1v2_IOMMU:
case VFIO_UNMAP_ALL:
- return 1;
+ return !ictx->no_iommu_mode;
case VFIO_NOIOMMU_IOMMU:
return IS_ENABLED(CONFIG_VFIO_NOIOMMU);
--
2.43.0
next reply other threads:[~2026-02-13 18:36 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-13 18:36 Jacob Pan [this message]
2026-03-03 0:29 ` [PATCH] iommufd: vfio compatibility extension check for noiommu mode Jason Gunthorpe
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