Hi Peng
Le 23/05/2016 à 11:47, Peng Fan a écrit :
> The vfio No-IOMMU mode was supported by this
> 'commit 03a76b60f8ba2797 ("vfio: Include No-IOMMU mode")',
> but it only support vfio-pci.
>
> Using vfio_iommu_group_get/put, but not iommu_group_get/put,
> the platform devices can be exposed to userspace with
> CONFIG_VFIO_NOIOMMU and the "enable_unsafe_noiommu_mode"
> option enabled.
>
> From 'commit 03a76b60f8ba2797 ("vfio: Include No-IOMMU mode")',
> "This should make it very clear that this mode is not safe.
> Additionally, CAP_SYS_RAWIO privileges are necessary to work
> with groups and containers using this mode. Groups making
> use of this support are named /dev/vfio/noiommu-$GROUP and
> can only make use of the special VFIO_NOIOMMU_IOMMU for the
> container. Use of this mode, specifically binding a device
> without a native IOMMU group to a VFIO bus driver will taint
> the kernel and should therefore not be considered supported."
>
> Signed-off-by: Peng Fan <van.freenix@xxxxxxxxx>
> Cc: Eric Auger <eric.auger@xxxxxxxxxx>
> Cc: Baptiste Reynal <b.reynal@xxxxxxxxxxxxxxxxxxxxxx>
> Cc: Alex Williamson <alex.williamson@xxxxxxxxxx>
Looks good to me.
Reviewed-by: Eric Auger <eric.auger@xxxxxxxxxx>
as a reminder may conflict with HiDma ACPI reset series.
Best Regards
Eric
> ---
>
> V3:
> The platform device can be programmed to do DMA without
> caring out mmap + VFIO_IOMMU_MAP_DMA which are not
> support by noiommu. So drop the last sentence of commit log
> in V2, which is misleading.
>
> V2:
> Rename subject to support No-IOMMU
> Add more commit log.
> I wrote a simple program following this
> https://github.com/virtualopensystems/vfio-host-test/blob/master/src_test/vfio_device_test.c
> ,no dma support. The device's register can be
> accessed in userspace using command './vfio_dev_test 30b60000.usdhc 0 1 platform'
>
> drivers/vfio/platform/vfio_platform_common.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c
> index e65b142..993b2f9 100644
> --- a/drivers/vfio/platform/vfio_platform_common.c
> +++ b/drivers/vfio/platform/vfio_platform_common.c
> @@ -561,7 +561,7 @@ int vfio_platform_probe_common(struct vfio_platform_device *vdev,
>
> vdev->device = dev;
>
> - group = iommu_group_get(dev);
> + group = vfio_iommu_group_get(dev);
> if (!group) {
> pr_err("VFIO: No IOMMU group for device %s\n", vdev->name);
> return -EINVAL;
> @@ -569,7 +569,7 @@ int vfio_platform_probe_common(struct vfio_platform_device *vdev,
>
> ret = vfio_add_group_dev(dev, &vfio_platform_ops, vdev);
> if (ret) {
> - iommu_group_put(group);
> + vfio_iommu_group_put(group, dev);
> return ret;
> }
>
> @@ -589,7 +589,7 @@ struct vfio_platform_device *vfio_platform_remove_common(struct device *dev)
>
> if (vdev) {
> vfio_platform_put_reset(vdev);
> - iommu_group_put(dev->iommu_group);
> + vfio_iommu_group_put(dev->iommu_group, dev);
> }
>
> return vdev;
>
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