From 6f01cc692a16405235d5c34056455b182682123c Mon Sep 17 00:00:00 2001 From: Alexey Kardashevskiy Date: Wed, 30 Nov 2016 17:52:02 +1100 Subject: [PATCH] vfio/spapr: Add a helper to create default DMA window There is already a helper to create a DMA window which does allocate a table and programs it to the IOMMU group. However tce_iommu_take_ownership_ddw() did not use it and did these 2 calls itself to simplify error path. Since we are going to delay the default window creation till the default window is accessed/removed or new window is added, we need a helper to create a default window from all these cases. This adds tce_iommu_create_default_window(). Since it relies on a VFIO container to have at least one IOMMU group (for future use), this changes tce_iommu_attach_group() to add a group to the container first and then call the new helper. Signed-off-by: Alexey Kardashevskiy Reviewed-by: David Gibson Acked-by: Alex Williamson Signed-off-by: Michael Ellerman --- drivers/vfio/vfio_iommu_spapr_tce.c | 87 ++++++++++++++--------------- 1 file changed, 42 insertions(+), 45 deletions(-) diff --git a/drivers/vfio/vfio_iommu_spapr_tce.c b/drivers/vfio/vfio_iommu_spapr_tce.c index 4efd2b20c35c..a67bbfdd86d5 100644 --- a/drivers/vfio/vfio_iommu_spapr_tce.c +++ b/drivers/vfio/vfio_iommu_spapr_tce.c @@ -710,6 +710,29 @@ static long tce_iommu_remove_window(struct tce_container *container, return 0; } +static long tce_iommu_create_default_window(struct tce_container *container) +{ + long ret; + __u64 start_addr = 0; + struct tce_iommu_group *tcegrp; + struct iommu_table_group *table_group; + + if (!tce_groups_attached(container)) + return -ENODEV; + + tcegrp = list_first_entry(&container->group_list, + struct tce_iommu_group, next); + table_group = iommu_group_get_iommudata(tcegrp->grp); + if (!table_group) + return -ENODEV; + + ret = tce_iommu_create_window(container, IOMMU_PAGE_SHIFT_4K, + table_group->tce32_size, 1, &start_addr); + WARN_ON_ONCE(!ret && start_addr); + + return ret; +} + static long tce_iommu_ioctl(void *iommu_data, unsigned int cmd, unsigned long arg) { @@ -1100,9 +1123,6 @@ static void tce_iommu_release_ownership_ddw(struct tce_container *container, static long tce_iommu_take_ownership_ddw(struct tce_container *container, struct iommu_table_group *table_group) { - long i, ret = 0; - struct iommu_table *tbl = NULL; - if (!table_group->ops->create_table || !table_group->ops->set_window || !table_group->ops->release_ownership) { WARN_ON_ONCE(1); @@ -1111,47 +1131,7 @@ static long tce_iommu_take_ownership_ddw(struct tce_container *container, table_group->ops->take_ownership(table_group); - /* - * If it the first group attached, check if there is - * a default DMA window and create one if none as - * the userspace expects it to exist. - */ - if (!tce_groups_attached(container) && !container->tables[0]) { - ret = tce_iommu_create_table(container, - table_group, - 0, /* window number */ - IOMMU_PAGE_SHIFT_4K, - table_group->tce32_size, - 1, /* default levels */ - &tbl); - if (ret) - goto release_exit; - else - container->tables[0] = tbl; - } - - /* Set all windows to the new group */ - for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) { - tbl = container->tables[i]; - - if (!tbl) - continue; - - /* Set the default window to a new group */ - ret = table_group->ops->set_window(table_group, i, tbl); - if (ret) - goto release_exit; - } - return 0; - -release_exit: - for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) - table_group->ops->unset_window(table_group, i); - - table_group->ops->release_ownership(table_group); - - return ret; } static int tce_iommu_attach_group(void *iommu_data, @@ -1161,6 +1141,7 @@ static int tce_iommu_attach_group(void *iommu_data, struct tce_container *container = iommu_data; struct iommu_table_group *table_group; struct tce_iommu_group *tcegrp = NULL; + bool create_default_window = false; mutex_lock(&container->lock); @@ -1203,14 +1184,30 @@ static int tce_iommu_attach_group(void *iommu_data, } if (!table_group->ops || !table_group->ops->take_ownership || - !table_group->ops->release_ownership) + !table_group->ops->release_ownership) { ret = tce_iommu_take_ownership(container, table_group); - else + } else { ret = tce_iommu_take_ownership_ddw(container, table_group); + if (!tce_groups_attached(container) && !container->tables[0]) + create_default_window = true; + } if (!ret) { tcegrp->grp = iommu_group; list_add(&tcegrp->next, &container->group_list); + /* + * If it the first group attached, check if there is + * a default DMA window and create one if none as + * the userspace expects it to exist. + */ + if (create_default_window) { + ret = tce_iommu_create_default_window(container); + if (ret) { + list_del(&tcegrp->next); + tce_iommu_release_ownership_ddw(container, + table_group); + } + } } unlock_exit: -- 2.20.1