Merge branch 'vfio-no-iommu' into iommufd.git for-next (bed9e516) · Commits · EulixOS / Software / Kernel

drivers/iommu/iommufd/Kconfig

+1 −1

Original line number	Diff line number	Diff line
		@@ -23,7 +23,7 @@ config IOMMUFD_VFIO_CONTAINER
		removed.

		IOMMUFD VFIO container emulation is known to lack certain features
		of the native VFIO container, such as no-IOMMU support, peer-to-peer
		of the native VFIO container, such as peer-to-peer
		DMA mapping, PPC IOMMU support, as well as other potentially
		undiscovered gaps. This option is currently intended for the
		purpose of testing IOMMUFD with unmodified userspace supporting VFIO

drivers/iommu/iommufd/iommufd_private.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -18,6 +18,8 @@ struct iommufd_ctx {
		struct xarray objects;

		u8 account_mode;
		/* Compatibility with VFIO no iommu */
		u8 no_iommu_mode;
		struct iommufd_ioas *vfio_ioas;
		};

drivers/iommu/iommufd/vfio_compat.c

+86 −19

Original line number	Diff line number	Diff line
		@@ -26,39 +26,84 @@ static struct iommufd_ioas get_compat_ioas(struct iommufd_ctx ictx)
		}

		/**
		* iommufd_vfio_compat_ioas_id - Return the IOAS ID that vfio should use
		* iommufd_vfio_compat_ioas_get_id - Ensure a compat IOAS exists
		* @ictx: Context to operate on
		* @out_ioas_id: The IOAS ID of the compatibility IOAS
		*
		* Return the ID of the current compatibility IOAS. The ID can be passed into
		* other functions that take an ioas_id.
		*/
		int iommufd_vfio_compat_ioas_get_id(struct iommufd_ctx ictx, u32 out_ioas_id)
		{
		struct iommufd_ioas *ioas;

		ioas = get_compat_ioas(ictx);
		if (IS_ERR(ioas))
		return PTR_ERR(ioas);
		*out_ioas_id = ioas->obj.id;
		iommufd_put_object(&ioas->obj);
		return 0;
		}
		EXPORT_SYMBOL_NS_GPL(iommufd_vfio_compat_ioas_get_id, IOMMUFD_VFIO);

		/**
		* iommufd_vfio_compat_set_no_iommu - Called when a no-iommu device is attached
		* @ictx: Context to operate on
		*
		* This allows selecting the VFIO_NOIOMMU_IOMMU and blocks normal types.
		*/
		int iommufd_vfio_compat_set_no_iommu(struct iommufd_ctx *ictx)
		{
		int ret;

		xa_lock(&ictx->objects);
		if (!ictx->vfio_ioas) {
		ictx->no_iommu_mode = 1;
		ret = 0;
		} else {
		ret = -EINVAL;
		}
		xa_unlock(&ictx->objects);
		return ret;
		}
		EXPORT_SYMBOL_NS_GPL(iommufd_vfio_compat_set_no_iommu, IOMMUFD_VFIO);

		/**
		* iommufd_vfio_compat_ioas_create - Ensure the compat IOAS is created
		* @ictx: Context to operate on
		* @out_ioas_id: The ioas_id the caller should use
		*
		* The compatibility IOAS is the IOAS that the vfio compatibility ioctls operate
		* on since they do not have an IOAS ID input in their ABI. Only attaching a
		* group should cause a default creation of the internal ioas, this returns the
		* existing ioas if it has already been assigned somehow.
		* group should cause a default creation of the internal ioas, this does nothing
		* if an existing ioas has already been assigned somehow.
		*/
		int iommufd_vfio_compat_ioas_id(struct iommufd_ctx ictx, u32 out_ioas_id)
		int iommufd_vfio_compat_ioas_create(struct iommufd_ctx *ictx)
		{
		struct iommufd_ioas *ioas = NULL;
		struct iommufd_ioas *out_ioas;
		int ret;

		ioas = iommufd_ioas_alloc(ictx);
		if (IS_ERR(ioas))
		return PTR_ERR(ioas);

		xa_lock(&ictx->objects);
		if (ictx->vfio_ioas && iommufd_lock_obj(&ictx->vfio_ioas->obj))
		out_ioas = ictx->vfio_ioas;
		else {
		out_ioas = ioas;
		ictx->vfio_ioas = ioas;
		/*
		* VFIO won't allow attaching a container to both iommu and no iommu
		* operation
		*/
		if (ictx->no_iommu_mode) {
		ret = -EINVAL;
		goto out_abort;
		}
		xa_unlock(&ictx->objects);

		*out_ioas_id = out_ioas->obj.id;
		if (out_ioas != ioas) {
		iommufd_put_object(&out_ioas->obj);
		iommufd_object_abort(ictx, &ioas->obj);
		return 0;
		if (ictx->vfio_ioas && iommufd_lock_obj(&ictx->vfio_ioas->obj)) {
		ret = 0;
		iommufd_put_object(&ictx->vfio_ioas->obj);
		goto out_abort;
		}
		ictx->vfio_ioas = ioas;
		xa_unlock(&ictx->objects);

		/*
		* An automatically created compat IOAS is treated as a userspace
		* created object. Userspace can learn the ID via IOMMU_VFIO_IOAS_GET,
		@@ -67,8 +112,13 @@ int iommufd_vfio_compat_ioas_id(struct iommufd_ctx ictx, u32 out_ioas_id)
		*/
		iommufd_object_finalize(ictx, &ioas->obj);
		return 0;

		out_abort:
		xa_unlock(&ictx->objects);
		iommufd_object_abort(ictx, &ioas->obj);
		return ret;
		}
		EXPORT_SYMBOL_NS_GPL(iommufd_vfio_compat_ioas_id, IOMMUFD_VFIO);
		EXPORT_SYMBOL_NS_GPL(iommufd_vfio_compat_ioas_create, IOMMUFD_VFIO);

		int iommufd_vfio_ioas(struct iommufd_ucmd *ucmd)
		{
		@@ -235,6 +285,9 @@ static int iommufd_vfio_check_extension(struct iommufd_ctx *ictx,
		case VFIO_UNMAP_ALL:
		return 1;

		case VFIO_NOIOMMU_IOMMU:
		return IS_ENABLED(CONFIG_VFIO_NOIOMMU);

		case VFIO_DMA_CC_IOMMU:
		return iommufd_vfio_cc_iommu(ictx);

		@@ -261,10 +314,24 @@ static int iommufd_vfio_check_extension(struct iommufd_ctx *ictx,

		static int iommufd_vfio_set_iommu(struct iommufd_ctx *ictx, unsigned long type)
		{
		bool no_iommu_mode = READ_ONCE(ictx->no_iommu_mode);
		struct iommufd_ioas *ioas = NULL;
		int rc = 0;

		if (type != VFIO_TYPE1_IOMMU && type != VFIO_TYPE1v2_IOMMU)
		/*
		* Emulation for NOIOMMU is imperfect in that VFIO blocks almost all
		* other ioctls. We let them keep working but they mostly fail since no
		* IOAS should exist.
		*/
		if (IS_ENABLED(CONFIG_VFIO_NOIOMMU) && type == VFIO_NOIOMMU_IOMMU &&
		no_iommu_mode) {
		if (!capable(CAP_SYS_RAWIO))
		return -EPERM;
		return 0;
		}

		if ((type != VFIO_TYPE1_IOMMU && type != VFIO_TYPE1v2_IOMMU) \|\|
		no_iommu_mode)
		return -EINVAL;

		/* VFIO fails the set_iommu if there is no group */

drivers/vfio/Kconfig

+1 −1

Original line number	Diff line number	Diff line
		@@ -32,6 +32,7 @@ config VFIO_IOMMU_SPAPR_TCE
		tristate
		depends on SPAPR_TCE_IOMMU
		default VFIO
		endif

		config VFIO_NOIOMMU
		bool "VFIO No-IOMMU support"
		@@ -46,7 +47,6 @@ config VFIO_NOIOMMU
		this mode since there is no IOMMU to provide DMA translation.

		If you don't know what to do here, say N.
		endif

		config VFIO_VIRQFD
		bool

drivers/vfio/container.c

+0 −7

Original line number	Diff line number	Diff line
		@@ -29,13 +29,6 @@ static struct vfio {
		struct mutex iommu_drivers_lock;
		} vfio;

		#ifdef CONFIG_VFIO_NOIOMMU
		bool vfio_noiommu __read_mostly;
		module_param_named(enable_unsafe_noiommu_mode,
		vfio_noiommu, bool, S_IRUGO \| S_IWUSR);
		MODULE_PARM_DESC(enable_unsafe_noiommu_mode, "Enable UNSAFE, no-IOMMU mode. This mode provides no device isolation, no DMA translation, no host kernel protection, cannot be used for device assignment to virtual machines, requires RAWIO permissions, and will taint the kernel. If you do not know what this is for, step away. (default: false)");
		#endif

		static void *vfio_noiommu_open(unsigned long arg)
		{
		if (arg != VFIO_NOIOMMU_IOMMU)