[PATCH v3 24/24] vfio: powerpc/spapr: Support Dynamic DMA windows

[Alexey Kardashevskiy <aik@ozlabs.ru>]

This adds create/remove window ioctls to create and remove DMA windows.

This changes VFIO_IOMMU_SPAPR_TCE_GET_INFO handler to return additional
information such as a number of supported windows and maximum number
levels of TCE tables.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
 arch/powerpc/include/asm/iommu.h    |   2 +-
 drivers/vfio/vfio_iommu_spapr_tce.c | 137 +++++++++++++++++++++++++++++++++++-
 include/uapi/linux/vfio.h           |  24 ++++++-
 3 files changed, 160 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/include/asm/iommu.h b/arch/powerpc/include/asm/iommu.h
index 33009f9..7ca1c8c 100644
--- a/arch/powerpc/include/asm/iommu.h
+++ b/arch/powerpc/include/asm/iommu.h
@@ -133,7 +133,7 @@ extern void iommu_free_table(struct iommu_table *tbl, const char *node_name);
 extern struct iommu_table *iommu_init_table(struct iommu_table * tbl,
 					    int nid);
 
-#define POWERPC_IOMMU_MAX_TABLES	1
+#define POWERPC_IOMMU_MAX_TABLES	2
 
 #define POWERPC_IOMMU_DEFAULT_LEVELS	1
 
diff --git a/drivers/vfio/vfio_iommu_spapr_tce.c b/drivers/vfio/vfio_iommu_spapr_tce.c
index 8bcafb7..d3a1cc9 100644
--- a/drivers/vfio/vfio_iommu_spapr_tce.c
+++ b/drivers/vfio/vfio_iommu_spapr_tce.c
@@ -300,6 +300,20 @@ static struct iommu_table *spapr_tce_find_table(
 	return ret;
 }
 
+static int spapr_tce_find_free_table(struct tce_container *container)
+{
+	int i;
+
+	for (i = 0; i < POWERPC_IOMMU_MAX_TABLES; ++i) {
+		struct iommu_table *tbl = &container->tables[i];
+
+		if (!tbl->it_size)
+			return i;
+	}
+
+	return -1;
+}
+
 static unsigned long tce_default_winsize(struct tce_container *container)
 {
 	struct tce_iommu_group *tcegrp;
@@ -594,7 +608,7 @@ static long tce_iommu_ioctl(void *iommu_data,
 				 unsigned int cmd, unsigned long arg)
 {
 	struct tce_container *container = iommu_data;
-	unsigned long minsz;
+	unsigned long minsz, ddwsz;
 	long ret;
 
 	switch (cmd) {
@@ -636,6 +650,15 @@ static long tce_iommu_ioctl(void *iommu_data,
 
 		info.dma32_window_start = iommu->tce32_start;
 		info.dma32_window_size = iommu->tce32_size;
+		info.windows_supported = iommu->windows_supported;
+		info.levels = iommu->levels;
+		info.flags = iommu->flags;
+
+		ddwsz = offsetofend(struct vfio_iommu_spapr_tce_info,
+				levels);
+
+		if (info.argsz == ddwsz)
+			minsz = ddwsz;
 
 		if (copy_to_user((void __user *)arg, &info, minsz))
 			return -EFAULT;
@@ -800,6 +823,118 @@ static long tce_iommu_ioctl(void *iommu_data,
 		return ret;
 	}
 
+	case VFIO_IOMMU_SPAPR_TCE_CREATE: {
+		struct vfio_iommu_spapr_tce_create create;
+		struct powerpc_iommu *iommu;
+		struct tce_iommu_group *tcegrp;
+		int num;
+
+		if (!tce_preregistered(container))
+			return -ENXIO;
+
+		minsz = offsetofend(struct vfio_iommu_spapr_tce_create,
+				start_addr);
+
+		if (copy_from_user(&create, (void __user *)arg, minsz))
+			return -EFAULT;
+
+		if (create.argsz < minsz)
+			return -EINVAL;
+
+		if (create.flags)
+			return -EINVAL;
+
+		num = spapr_tce_find_free_table(container);
+		if (num < 0)
+			return -ENOSYS;
+
+		tcegrp = list_first_entry(&container->group_list,
+				struct tce_iommu_group, next);
+		iommu = iommu_group_get_iommudata(tcegrp->grp);
+
+		ret = iommu->ops->create_table(iommu, num,
+				create.page_shift, create.window_shift,
+				create.levels,
+				&container->tables[num]);
+		if (ret)
+			return ret;
+
+		list_for_each_entry(tcegrp, &container->group_list, next) {
+			struct powerpc_iommu *iommutmp =
+					iommu_group_get_iommudata(tcegrp->grp);
+
+			if (WARN_ON_ONCE(iommutmp->ops != iommu->ops))
+				return -EFAULT;
+
+			ret = iommu->ops->set_window(iommutmp, num,
+					&container->tables[num]);
+			if (ret)
+				return ret;
+		}
+
+		create.start_addr =
+				container->tables[num].it_offset <<
+				container->tables[num].it_page_shift;
+
+		if (copy_to_user((void __user *)arg, &create, minsz))
+			return -EFAULT;
+
+		mutex_lock(&container->lock);
+		mutex_unlock(&container->lock);
+
+		return ret;
+	}
+	case VFIO_IOMMU_SPAPR_TCE_REMOVE: {
+		struct vfio_iommu_spapr_tce_remove remove;
+		struct powerpc_iommu *iommu = NULL;
+		struct iommu_table *tbl;
+		struct tce_iommu_group *tcegrp;
+		int num;
+
+		if (!tce_preregistered(container))
+			return -ENXIO;
+
+		minsz = offsetofend(struct vfio_iommu_spapr_tce_remove,
+				start_addr);
+
+		if (copy_from_user(&remove, (void __user *)arg, minsz))
+			return -EFAULT;
+
+		if (remove.argsz < minsz)
+			return -EINVAL;
+
+		if (remove.flags)
+			return -EINVAL;
+
+
+		tbl = spapr_tce_find_table(container, remove.start_addr);
+		if (!tbl)
+			return -EINVAL;
+
+		/* Detach windows from IOMMUs */
+		mutex_lock(&container->lock);
+
+		/* Detach groups from IOMMUs */
+		num = tbl - container->tables;
+		list_for_each_entry(tcegrp, &container->group_list, next) {
+			iommu = iommu_group_get_iommudata(tcegrp->grp);
+			if (container->tables[num].it_size)
+				iommu->ops->unset_window(iommu, num);
+		}
+
+		/* Free table */
+		tcegrp = list_first_entry(&container->group_list,
+				struct tce_iommu_group, next);
+		iommu = iommu_group_get_iommudata(tcegrp->grp);
+
+		tce_iommu_clear(container, tbl,
+				tbl->it_offset, tbl->it_size);
+		iommu->ops->free_table(tbl);
+
+		mutex_unlock(&container->lock);
+
+		return 0;
+	}
 	}
 
 	return -ENOTTY;
diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index 2bb0c9b..7ed7000 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -483,9 +483,11 @@ struct vfio_iommu_type1_unregister_memory {
  */
 struct vfio_iommu_spapr_tce_info {
 	__u32 argsz;
-	__u32 flags;			/* reserved for future use */
+	__u32 flags;
 	__u32 dma32_window_start;	/* 32 bit window start (bytes) */
 	__u32 dma32_window_size;	/* 32 bit window size (bytes) */
+	__u32 windows_supported;
+	__u32 levels;
 };
 
 #define VFIO_IOMMU_SPAPR_TCE_GET_INFO	_IO(VFIO_TYPE, VFIO_BASE + 12)
@@ -521,6 +523,26 @@ struct vfio_eeh_pe_op {
 
 #define VFIO_EEH_PE_OP			_IO(VFIO_TYPE, VFIO_BASE + 21)
 
+struct vfio_iommu_spapr_tce_create {
+	__u32 argsz;
+	__u32 flags;
+	/* in */
+	__u32 page_shift;
+	__u32 window_shift;
+	__u32 levels;
+	/* out */
+	__u64 start_addr;
+};
+#define VFIO_IOMMU_SPAPR_TCE_CREATE	_IO(VFIO_TYPE, VFIO_BASE + 19)
+
+struct vfio_iommu_spapr_tce_remove {
+	__u32 argsz;
+	__u32 flags;
+	/* in */
+	__u64 start_addr;
+};
+#define VFIO_IOMMU_SPAPR_TCE_REMOVE	_IO(VFIO_TYPE, VFIO_BASE + 20)
+
 /* ***************************************************************** */
 
 #endif /* _UAPIVFIO_H */
-- 
2.0.0