diff mbox series

[v3,08/19] iommufd: Add IOMMU_HWPT_SET_DIRTY

Message ID 20230923012511.10379-9-joao.m.martins@oracle.com (mailing list archive)
State New, archived
Headers show
Series IOMMUFD Dirty Tracking | expand

Commit Message

Joao Martins Sept. 23, 2023, 1:25 a.m. UTC
Every IOMMU driver should be able to implement the needed iommu domain ops
to control dirty tracking.

Connect a hw_pagetable to the IOMMU core dirty tracking ops, specifically
the ability to enable/disable dirty tracking on an IOMMU domain
(hw_pagetable id). To that end add an io_pagetable kernel API to toggle
dirty tracking:

* iopt_set_dirty_tracking(iopt, [domain], state)

The intended caller of this is via the hw_pagetable object that is created.

Internally it will ensure the leftover dirty state is cleared /right
before/ dirty tracking starts. This is also useful for iommu drivers
which may decide that dirty tracking is always-enabled at boot without
wanting to toggle dynamically via corresponding iommu domain op.

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
---
 drivers/iommu/iommufd/hw_pagetable.c    | 21 ++++++++++
 drivers/iommu/iommufd/io_pagetable.c    | 56 +++++++++++++++++++++++++
 drivers/iommu/iommufd/iommufd_private.h | 11 +++++
 drivers/iommu/iommufd/main.c            |  3 ++
 include/uapi/linux/iommufd.h            | 27 ++++++++++++
 5 files changed, 118 insertions(+)

Comments

Jason Gunthorpe Oct. 13, 2023, 4:13 p.m. UTC | #1
On Sat, Sep 23, 2023 at 02:25:00AM +0100, Joao Martins wrote:
> diff --git a/drivers/iommu/iommufd/hw_pagetable.c b/drivers/iommu/iommufd/hw_pagetable.c
> index 32e259245314..22354b0ba554 100644
> --- a/drivers/iommu/iommufd/hw_pagetable.c
> +++ b/drivers/iommu/iommufd/hw_pagetable.c
> @@ -198,3 +198,24 @@ int iommufd_hwpt_alloc(struct iommufd_ucmd *ucmd)
>  	iommufd_put_object(&idev->obj);
>  	return rc;
>  }
> +
> +int iommufd_hwpt_set_dirty(struct iommufd_ucmd *ucmd)
> +{
> +	struct iommu_hwpt_set_dirty *cmd = ucmd->cmd;
> +	struct iommufd_hw_pagetable *hwpt;
> +	struct iommufd_ioas *ioas;
> +	int rc = -EOPNOTSUPP;

Default is never used?

> +	bool enable;
> +
> +	hwpt = iommufd_get_hwpt(ucmd, cmd->hwpt_id);
> +	if (IS_ERR(hwpt))
> +		return PTR_ERR(hwpt);
> +
> +	ioas = hwpt->ioas;
> +	enable = cmd->flags & IOMMU_DIRTY_TRACKING_ENABLED;

Check that incoming flags are not invalid

if (cmd->flags & ~IOMMU_DIRTY_TRACKING_ENABLED)
    return -EOPNOTSUPP

> diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c
> index e71523cbd0de..ec0c34086af3 100644
> --- a/drivers/iommu/iommufd/main.c
> +++ b/drivers/iommu/iommufd/main.c
> @@ -315,6 +315,7 @@ union ucmd_buffer {
>  	struct iommu_ioas_unmap unmap;
>  	struct iommu_option option;
>  	struct iommu_vfio_ioas vfio_ioas;
> +	struct iommu_hwpt_set_dirty set_dirty;
>  #ifdef CONFIG_IOMMUFD_TEST
>  	struct iommu_test_cmd test;
>  #endif
> @@ -358,6 +359,8 @@ static const struct iommufd_ioctl_op iommufd_ioctl_ops[] = {
>  		 val64),
>  	IOCTL_OP(IOMMU_VFIO_IOAS, iommufd_vfio_ioas, struct iommu_vfio_ioas,
>  		 __reserved),
> +	IOCTL_OP(IOMMU_HWPT_SET_DIRTY, iommufd_hwpt_set_dirty,
> +		 struct iommu_hwpt_set_dirty, __reserved),
>  #ifdef CONFIG_IOMMUFD_TEST
>  	IOCTL_OP(IOMMU_TEST_CMD, iommufd_test, struct iommu_test_cmd, last),
>  #endif

These two lists of things are sorted
> +
> +/*

/** ?

> + * enum iommufd_set_dirty_flags - Flags for steering dirty tracking
> + * @IOMMU_DIRTY_TRACKING_DISABLED: Disables dirty tracking
> + * @IOMMU_DIRTY_TRACKING_ENABLED: Enables dirty tracking
> + */
> +enum iommufd_hwpt_set_dirty_flags {
> +	IOMMU_DIRTY_TRACKING_DISABLED = 0,
> +	IOMMU_DIRTY_TRACKING_ENABLED = 1,
> +};

Probably get rid of disabled and call it _ENABLE so it is actualy a
flag

Jason
diff mbox series

Patch

diff --git a/drivers/iommu/iommufd/hw_pagetable.c b/drivers/iommu/iommufd/hw_pagetable.c
index 32e259245314..22354b0ba554 100644
--- a/drivers/iommu/iommufd/hw_pagetable.c
+++ b/drivers/iommu/iommufd/hw_pagetable.c
@@ -198,3 +198,24 @@  int iommufd_hwpt_alloc(struct iommufd_ucmd *ucmd)
 	iommufd_put_object(&idev->obj);
 	return rc;
 }
+
+int iommufd_hwpt_set_dirty(struct iommufd_ucmd *ucmd)
+{
+	struct iommu_hwpt_set_dirty *cmd = ucmd->cmd;
+	struct iommufd_hw_pagetable *hwpt;
+	struct iommufd_ioas *ioas;
+	int rc = -EOPNOTSUPP;
+	bool enable;
+
+	hwpt = iommufd_get_hwpt(ucmd, cmd->hwpt_id);
+	if (IS_ERR(hwpt))
+		return PTR_ERR(hwpt);
+
+	ioas = hwpt->ioas;
+	enable = cmd->flags & IOMMU_DIRTY_TRACKING_ENABLED;
+
+	rc = iopt_set_dirty_tracking(&ioas->iopt, hwpt->domain, enable);
+
+	iommufd_put_object(&hwpt->obj);
+	return rc;
+}
diff --git a/drivers/iommu/iommufd/io_pagetable.c b/drivers/iommu/iommufd/io_pagetable.c
index d70617447392..b9e58601d1d4 100644
--- a/drivers/iommu/iommufd/io_pagetable.c
+++ b/drivers/iommu/iommufd/io_pagetable.c
@@ -479,6 +479,62 @@  int iopt_read_and_clear_dirty_data(struct io_pagetable *iopt,
 	down_read(&iopt->iova_rwsem);
 	ret = iommu_read_and_clear_dirty(domain, flags, bitmap);
 	up_read(&iopt->iova_rwsem);
+
+	return ret;
+}
+
+static int iopt_clear_dirty_data(struct io_pagetable *iopt,
+				 struct iommu_domain *domain)
+{
+	const struct iommu_dirty_ops *ops = domain->dirty_ops;
+	struct iommu_iotlb_gather gather;
+	struct iommu_dirty_bitmap dirty;
+	struct iopt_area *area;
+	int ret = 0;
+
+	lockdep_assert_held_read(&iopt->iova_rwsem);
+
+	iommu_dirty_bitmap_init(&dirty, NULL, &gather);
+
+	for (area = iopt_area_iter_first(iopt, 0, ULONG_MAX); area;
+	     area = iopt_area_iter_next(area, 0, ULONG_MAX)) {
+		if (!area->pages)
+			continue;
+
+		ret = ops->read_and_clear_dirty(domain,
+						iopt_area_iova(area),
+						iopt_area_length(area), 0,
+						&dirty);
+		if (ret)
+			break;
+	}
+
+	iommu_iotlb_sync(domain, &gather);
+	return ret;
+}
+
+int iopt_set_dirty_tracking(struct io_pagetable *iopt,
+			    struct iommu_domain *domain, bool enable)
+{
+	const struct iommu_dirty_ops *ops = domain->dirty_ops;
+	int ret = 0;
+
+	if (!ops)
+		return -EOPNOTSUPP;
+
+	down_read(&iopt->iova_rwsem);
+
+	/* Clear dirty bits from PTEs to ensure a clean snapshot */
+	if (enable) {
+		ret = iopt_clear_dirty_data(iopt, domain);
+		if (ret)
+			goto out_unlock;
+	}
+
+	ret = ops->set_dirty_tracking(domain, enable);
+
+out_unlock:
+	up_read(&iopt->iova_rwsem);
 	return ret;
 }
 
diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h
index 84ec1df29074..1101a1914513 100644
--- a/drivers/iommu/iommufd/iommufd_private.h
+++ b/drivers/iommu/iommufd/iommufd_private.h
@@ -10,6 +10,7 @@ 
 #include <linux/uaccess.h>
 #include <linux/iommu.h>
 #include <linux/iova_bitmap.h>
+#include <uapi/linux/iommufd.h>
 
 struct iommu_domain;
 struct iommu_group;
@@ -83,6 +84,8 @@  int iopt_read_and_clear_dirty_data(struct io_pagetable *iopt,
 				   struct iommu_domain *domain,
 				   unsigned long flags,
 				   struct iommufd_dirty_data *bitmap);
+int iopt_set_dirty_tracking(struct io_pagetable *iopt,
+			    struct iommu_domain *domain, bool enable);
 
 void iommufd_access_notify_unmap(struct io_pagetable *iopt, unsigned long iova,
 				 unsigned long length);
@@ -254,6 +257,14 @@  struct iommufd_hw_pagetable {
 	struct list_head hwpt_item;
 };
 
+static inline struct iommufd_hw_pagetable *iommufd_get_hwpt(
+					struct iommufd_ucmd *ucmd, u32 id)
+{
+	return container_of(iommufd_get_object(ucmd->ictx, id,
+					       IOMMUFD_OBJ_HW_PAGETABLE),
+			    struct iommufd_hw_pagetable, obj);
+}
+int iommufd_hwpt_set_dirty(struct iommufd_ucmd *ucmd);
 struct iommufd_hw_pagetable *
 iommufd_hw_pagetable_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas,
 			   struct iommufd_device *idev, u32 flags,
diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c
index e71523cbd0de..ec0c34086af3 100644
--- a/drivers/iommu/iommufd/main.c
+++ b/drivers/iommu/iommufd/main.c
@@ -315,6 +315,7 @@  union ucmd_buffer {
 	struct iommu_ioas_unmap unmap;
 	struct iommu_option option;
 	struct iommu_vfio_ioas vfio_ioas;
+	struct iommu_hwpt_set_dirty set_dirty;
 #ifdef CONFIG_IOMMUFD_TEST
 	struct iommu_test_cmd test;
 #endif
@@ -358,6 +359,8 @@  static const struct iommufd_ioctl_op iommufd_ioctl_ops[] = {
 		 val64),
 	IOCTL_OP(IOMMU_VFIO_IOAS, iommufd_vfio_ioas, struct iommu_vfio_ioas,
 		 __reserved),
+	IOCTL_OP(IOMMU_HWPT_SET_DIRTY, iommufd_hwpt_set_dirty,
+		 struct iommu_hwpt_set_dirty, __reserved),
 #ifdef CONFIG_IOMMUFD_TEST
 	IOCTL_OP(IOMMU_TEST_CMD, iommufd_test, struct iommu_test_cmd, last),
 #endif
diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h
index cd94a9d8ce66..37079e72d243 100644
--- a/include/uapi/linux/iommufd.h
+++ b/include/uapi/linux/iommufd.h
@@ -47,6 +47,7 @@  enum {
 	IOMMUFD_CMD_VFIO_IOAS,
 	IOMMUFD_CMD_HWPT_ALLOC,
 	IOMMUFD_CMD_GET_HW_INFO,
+	IOMMUFD_CMD_HWPT_SET_DIRTY,
 };
 
 /**
@@ -454,4 +455,30 @@  struct iommu_hw_info {
 	__u32 __reserved;
 };
 #define IOMMU_GET_HW_INFO _IO(IOMMUFD_TYPE, IOMMUFD_CMD_GET_HW_INFO)
+
+/*
+ * enum iommufd_set_dirty_flags - Flags for steering dirty tracking
+ * @IOMMU_DIRTY_TRACKING_DISABLED: Disables dirty tracking
+ * @IOMMU_DIRTY_TRACKING_ENABLED: Enables dirty tracking
+ */
+enum iommufd_hwpt_set_dirty_flags {
+	IOMMU_DIRTY_TRACKING_DISABLED = 0,
+	IOMMU_DIRTY_TRACKING_ENABLED = 1,
+};
+
+/**
+ * struct iommu_hwpt_set_dirty - ioctl(IOMMU_HWPT_SET_DIRTY)
+ * @size: sizeof(struct iommu_hwpt_set_dirty)
+ * @flags: Flags to control dirty tracking status.
+ * @hwpt_id: HW pagetable ID that represents the IOMMU domain.
+ *
+ * Toggle dirty tracking on an HW pagetable.
+ */
+struct iommu_hwpt_set_dirty {
+	__u32 size;
+	__u32 flags;
+	__u32 hwpt_id;
+	__u32 __reserved;
+};
+#define IOMMU_HWPT_SET_DIRTY _IO(IOMMUFD_TYPE, IOMMUFD_CMD_HWPT_SET_DIRTY)
 #endif