Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754494AbbDJGcy (ORCPT ); Fri, 10 Apr 2015 02:32:54 -0400 Received: from e23smtp05.au.ibm.com ([202.81.31.147]:49177 "EHLO e23smtp05.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754226AbbDJGcq (ORCPT ); Fri, 10 Apr 2015 02:32:46 -0400 From: Alexey Kardashevskiy To: linuxppc-dev@lists.ozlabs.org Cc: Alexey Kardashevskiy , Benjamin Herrenschmidt , Paul Mackerras , Alex Williamson , linux-kernel@vger.kernel.org Subject: [PATCH kernel v8 30/31] vfio: powerpc/spapr: Support multiple groups in one container if possible Date: Fri, 10 Apr 2015 16:31:12 +1000 Message-Id: <1428647473-11738-31-git-send-email-aik@ozlabs.ru> X-Mailer: git-send-email 2.0.0 In-Reply-To: <1428647473-11738-1-git-send-email-aik@ozlabs.ru> References: <1428647473-11738-1-git-send-email-aik@ozlabs.ru> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15041006-0017-0000-0000-0000010DA9AF Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 15172 Lines: 506 At the moment only one group per container is supported. POWER8 CPUs have more flexible design and allows naving 2 TCE tables per IOMMU group so we can relax this limitation and support multiple groups per container. This adds TCE table descriptors to a container and uses iommu_table_group_ops to create/set DMA windows on IOMMU groups so the same TCE tables will be shared between several IOMMU groups. Signed-off-by: Alexey Kardashevskiy --- Changes: v7: * updated doc --- Documentation/vfio.txt | 8 +- drivers/vfio/vfio_iommu_spapr_tce.c | 289 ++++++++++++++++++++++++++---------- 2 files changed, 214 insertions(+), 83 deletions(-) diff --git a/Documentation/vfio.txt b/Documentation/vfio.txt index 94328c8..7dcf2b5 100644 --- a/Documentation/vfio.txt +++ b/Documentation/vfio.txt @@ -289,10 +289,12 @@ PPC64 sPAPR implementation note This implementation has some specifics: -1) Only one IOMMU group per container is supported as an IOMMU group -represents the minimal entity which isolation can be guaranteed for and -groups are allocated statically, one per a Partitionable Endpoint (PE) +1) On older systems (POWER7 with P5IOC2/IODA1) only one IOMMU group per +container is supported as an IOMMU table is allocated at the boot time, +one table per a IOMMU group which is a Partitionable Endpoint (PE) (PE is often a PCI domain but not always). +Newer systems (POWER8 with IODA2) have improved hardware design which allows +to remove this limitation and have multiple IOMMU groups per a VFIO container. 2) The hardware supports so called DMA windows - the PCI address range within which DMA transfer is allowed, any attempt to access address space diff --git a/drivers/vfio/vfio_iommu_spapr_tce.c b/drivers/vfio/vfio_iommu_spapr_tce.c index 3eded0d..a9520a8 100644 --- a/drivers/vfio/vfio_iommu_spapr_tce.c +++ b/drivers/vfio/vfio_iommu_spapr_tce.c @@ -89,10 +89,16 @@ static void decrement_locked_vm(long npages) */ struct tce_container { struct mutex lock; - struct iommu_group *grp; bool enabled; unsigned long locked_pages; bool v2; + struct iommu_table tables[IOMMU_TABLE_GROUP_MAX_TABLES]; + struct list_head group_list; +}; + +struct tce_iommu_group { + struct list_head next; + struct iommu_group *grp; }; static long tce_unregister_pages(struct tce_container *container, @@ -154,20 +160,20 @@ static bool tce_page_is_contained(struct page *page, unsigned page_shift) return (PAGE_SHIFT + compound_order(compound_head(page))) >= page_shift; } +static inline bool tce_groups_attached(struct tce_container *container) +{ + return !list_empty(&container->group_list); +} + static struct iommu_table *spapr_tce_find_table( struct tce_container *container, phys_addr_t ioba) { long i; struct iommu_table *ret = NULL; - struct iommu_table_group *table_group; - - table_group = iommu_group_get_iommudata(container->grp); - if (!table_group) - return NULL; for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) { - struct iommu_table *tbl = &table_group->tables[i]; + struct iommu_table *tbl = &container->tables[i]; unsigned long entry = ioba >> tbl->it_page_shift; unsigned long start = tbl->it_offset; unsigned long end = start + tbl->it_size; @@ -185,11 +191,8 @@ static int tce_iommu_enable(struct tce_container *container) { int ret = 0; unsigned long locked; - struct iommu_table *tbl; struct iommu_table_group *table_group; - - if (!container->grp) - return -ENXIO; + struct tce_iommu_group *tcegrp; if (!current->mm) return -ESRCH; /* process exited */ @@ -222,12 +225,24 @@ static int tce_iommu_enable(struct tce_container *container) * as this information is only available from KVM and VFIO is * KVM agnostic. */ - table_group = iommu_group_get_iommudata(container->grp); + 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; - tbl = &table_group->tables[0]; - locked = (tbl->it_size << tbl->it_page_shift) >> PAGE_SHIFT; + /* + * We do not allow enabling a group if no DMA-able memory was + * registered as there is no way to know how much we should + * increment the locked_vm counter. + */ + if (!table_group->tce32_size) + return -EPERM; + + locked = table_group->tce32_size >> PAGE_SHIFT; ret = try_increment_locked_vm(locked); if (ret) return ret; @@ -266,6 +281,8 @@ static void *tce_iommu_open(unsigned long arg) return ERR_PTR(-ENOMEM); mutex_init(&container->lock); + INIT_LIST_HEAD_RCU(&container->group_list); + container->v2 = arg == VFIO_SPAPR_TCE_v2_IOMMU; return container; @@ -274,15 +291,35 @@ static void *tce_iommu_open(unsigned long arg) static int tce_iommu_clear(struct tce_container *container, struct iommu_table *tbl, unsigned long entry, unsigned long pages); +static void tce_iommu_free_table(struct iommu_table *tbl); static void tce_iommu_release(void *iommu_data) { struct tce_container *container = iommu_data; + struct iommu_table_group *table_group; + int i; + struct tce_iommu_group *tcegrp; - WARN_ON(container->grp); + while (tce_groups_attached(container)) { + tcegrp = list_first_entry(&container->group_list, + struct tce_iommu_group, next); + table_group = iommu_group_get_iommudata(tcegrp->grp); + tce_iommu_detach_group(iommu_data, tcegrp->grp); + } - if (container->grp) - tce_iommu_detach_group(iommu_data, container->grp); + /* Free tables */ + for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) { + struct iommu_table *tbl = &container->tables[i]; + + if (!tbl->it_size) + continue; + + tce_iommu_clear(container, tbl, + tbl->it_offset, tbl->it_size); + + if (tbl->it_ops && tbl->it_ops->free) + tce_iommu_free_table(tbl); + } tce_iommu_disable(container); @@ -498,6 +535,44 @@ static long tce_iommu_build_v2(struct tce_container *container, return ret; } +static long tce_iommu_create_table(struct iommu_table_group *table_group, + int num, + __u32 page_shift, + __u64 window_size, + __u32 levels, + struct iommu_table *tbl) +{ + long ret; + unsigned long table_size; + + table_size = table_group->ops->get_table_size(page_shift, window_size, + levels) >> PAGE_SHIFT; + + ret = try_increment_locked_vm(table_size); + if (ret) + return ret; + + ret = table_group->ops->create_table(table_group, num, + page_shift, window_size, levels, tbl); + + if (ret) + decrement_locked_vm(table_size); + + return ret; +} + +static void tce_iommu_free_table(struct iommu_table *tbl) +{ + unsigned long pages = tbl->it_allocated_size >> PAGE_SHIFT; + + if (!tbl->it_allocated_size) + return; + + tbl->it_ops->free(tbl); + decrement_locked_vm(pages); + memset(tbl, 0, sizeof(*tbl)); +} + static long tce_iommu_ioctl(void *iommu_data, unsigned int cmd, unsigned long arg) { @@ -521,16 +596,17 @@ static long tce_iommu_ioctl(void *iommu_data, case VFIO_IOMMU_SPAPR_TCE_GET_INFO: { struct vfio_iommu_spapr_tce_info info; - struct iommu_table *tbl; + struct tce_iommu_group *tcegrp; struct iommu_table_group *table_group; - if (WARN_ON(!container->grp)) + if (!tce_groups_attached(container)) return -ENXIO; - table_group = iommu_group_get_iommudata(container->grp); + tcegrp = list_first_entry(&container->group_list, + struct tce_iommu_group, next); + table_group = iommu_group_get_iommudata(tcegrp->grp); - tbl = &table_group->tables[0]; - if (WARN_ON_ONCE(!tbl)) + if (!table_group) return -ENXIO; minsz = offsetofend(struct vfio_iommu_spapr_tce_info, @@ -542,9 +618,9 @@ static long tce_iommu_ioctl(void *iommu_data, if (info.argsz < minsz) return -EINVAL; - info.dma32_window_start = tbl->it_offset << tbl->it_page_shift; - info.dma32_window_size = tbl->it_size << tbl->it_page_shift; info.flags = 0; + info.dma32_window_start = table_group->tce32_start; + info.dma32_window_size = table_group->tce32_size; if (copy_to_user((void __user *)arg, &info, minsz)) return -EFAULT; @@ -721,12 +797,20 @@ static long tce_iommu_ioctl(void *iommu_data, tce_iommu_disable(container); mutex_unlock(&container->lock); return 0; - case VFIO_EEH_PE_OP: - if (!container->grp) - return -ENODEV; - return vfio_spapr_iommu_eeh_ioctl(container->grp, - cmd, arg); + case VFIO_EEH_PE_OP: { + struct tce_iommu_group *tcegrp; + + ret = 0; + list_for_each_entry(tcegrp, &container->group_list, next) { + ret = vfio_spapr_iommu_eeh_ioctl(tcegrp->grp, + cmd, arg); + if (ret) + return ret; + } + return ret; + } + } return -ENOTTY; @@ -735,63 +819,111 @@ static long tce_iommu_ioctl(void *iommu_data, static int tce_iommu_attach_group(void *iommu_data, struct iommu_group *iommu_group) { - int ret; + int ret, i; struct tce_container *container = iommu_data; struct iommu_table_group *table_group; + struct tce_iommu_group *tcegrp = NULL; + bool first_group = !tce_groups_attached(container); mutex_lock(&container->lock); /* pr_debug("tce_vfio: Attaching group #%u to iommu %p\n", iommu_group_id(iommu_group), iommu_group); */ - if (container->grp) { - pr_warn("tce_vfio: Only one group per IOMMU container is allowed, existing id=%d, attaching id=%d\n", - iommu_group_id(container->grp), - iommu_group_id(iommu_group)); - ret = -EBUSY; - goto unlock_exit; - } - - if (container->enabled) { - pr_err("tce_vfio: attaching group #%u to enabled container\n", - iommu_group_id(iommu_group)); - ret = -EBUSY; - goto unlock_exit; - } - table_group = iommu_group_get_iommudata(iommu_group); - if (!table_group) { - ret = -ENXIO; + + if (!first_group && (!table_group->ops || + !table_group->ops->set_ownership)) { + ret = -EBUSY; + goto unlock_exit; + } + + /* Check if new group has the same iommu_ops (i.e. compatible) */ + list_for_each_entry(tcegrp, &container->group_list, next) { + struct iommu_table_group *table_group_tmp; + + if (tcegrp->grp == iommu_group) { + pr_warn("tce_vfio: Group %d is already attached\n", + iommu_group_id(iommu_group)); + ret = -EBUSY; + goto unlock_exit; + } + table_group_tmp = iommu_group_get_iommudata(tcegrp->grp); + if (table_group_tmp->ops != table_group->ops) { + pr_warn("tce_vfio: Group %d is incompatible with group %d\n", + iommu_group_id(iommu_group), + iommu_group_id(tcegrp->grp)); + ret = -EPERM; + goto unlock_exit; + } + } + + tcegrp = kzalloc(sizeof(*tcegrp), GFP_KERNEL); + if (!tcegrp) { + ret = -ENOMEM; goto unlock_exit; } if (!table_group->ops || !table_group->ops->set_ownership) { ret = iommu_take_ownership(table_group); + if (!ret) + container->tables[0] = table_group->tables[0]; } else if (!table_group->ops->create_table || !table_group->ops->set_window) { WARN_ON_ONCE(1); ret = -EFAULT; } else { + table_group->ops->set_ownership(table_group, true); /* - * Disable iommu bypass, otherwise the user can DMA to all of - * our physical memory via the bypass window instead of just - * the pages that has been explicitly mapped into the iommu + * If it the first group attached, check if there is any window + * created and create one if none. */ - struct iommu_table tbltmp = { 0 }, *tbl = &tbltmp; - - table_group->ops->set_ownership(table_group, true); - ret = table_group->ops->create_table(table_group, 0, - IOMMU_PAGE_SHIFT_4K, - table_group->tce32_size, 1, tbl); - if (!ret) - ret = table_group->ops->set_window(table_group, 0, tbl); + if (first_group) { + bool found = false; + + for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) { + if (!container->tables[i].it_size) + continue; + + found = true; + break; + } + if (!found) { + struct iommu_table *tbl = &container->tables[0]; + + ret = tce_iommu_create_table( + table_group, 0, + IOMMU_PAGE_SHIFT_4K, + table_group->tce32_size, 1, + tbl); + if (ret) + goto unlock_exit; + } + } + + /* Set all windows to the new group */ + for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) { + struct iommu_table *tbl = &container->tables[i]; + + if (!tbl->it_size) + continue; + + /* Set the default window to a new group */ + ret = table_group->ops->set_window(table_group, i, tbl); + if (ret) + break; + } } if (ret) goto unlock_exit; - container->grp = iommu_group; + tcegrp->grp = iommu_group; + list_add(&tcegrp->next, &container->group_list); unlock_exit: + if (ret && tcegrp) + kfree(tcegrp); + mutex_unlock(&container->lock); return ret; @@ -802,25 +934,27 @@ static void tce_iommu_detach_group(void *iommu_data, { struct tce_container *container = iommu_data; struct iommu_table_group *table_group; + struct tce_iommu_group *tcegrp, *tcetmp; long i; + bool found = false; mutex_lock(&container->lock); - if (iommu_group != container->grp) { - pr_warn("tce_vfio: detaching group #%u, expected group is #%u\n", - iommu_group_id(iommu_group), - iommu_group_id(container->grp)); + + list_for_each_entry_safe(tcegrp, tcetmp, &container->group_list, next) { + if (tcegrp->grp != iommu_group) + continue; + found = true; + break; + } + + if (!found) { + pr_warn("tce_vfio: detaching unattached group #%u\n", + iommu_group_id(iommu_group)); goto unlock_exit; } - if (container->enabled) { - pr_warn("tce_vfio: detaching group #%u from enabled container, forcing disable\n", - iommu_group_id(container->grp)); - tce_iommu_disable(container); - } - - /* pr_debug("tce_vfio: detaching group #%u from iommu %p\n", - iommu_group_id(iommu_group), iommu_group); */ - container->grp = NULL; + list_del(&tcegrp->next); + kfree(tcegrp); table_group = iommu_group_get_iommudata(iommu_group); BUG_ON(!table_group); @@ -828,7 +962,7 @@ static void tce_iommu_detach_group(void *iommu_data, /* Kernel owns the device now, we can restore bypass */ if (!table_group->ops || !table_group->ops->set_ownership) { for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) { - struct iommu_table *tbl = &table_group->tables[i]; + struct iommu_table *tbl = &container->tables[i]; if (!tbl->it_size) continue; @@ -837,20 +971,15 @@ static void tce_iommu_detach_group(void *iommu_data, goto unlock_exit; tce_iommu_clear(container, tbl, tbl->it_offset, tbl->it_size); + + memset(tbl, 0, sizeof(*tbl)); } iommu_release_ownership(table_group); } else if (!table_group->ops->unset_window) { WARN_ON_ONCE(1); } else { for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) { - struct iommu_table *tbl = &table_group->tables[i]; - table_group->ops->unset_window(table_group, i); - tce_iommu_clear(container, tbl, - tbl->it_offset, tbl->it_size); - - if (tbl->it_ops->free) - tbl->it_ops->free(tbl); } table_group->ops->set_ownership(table_group, false); -- 2.0.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/