From patchwork Wed Nov 30 06:52:03 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexey Kardashevskiy X-Patchwork-Id: 9453787 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id B5A1360756 for ; Wed, 30 Nov 2016 06:52:30 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A84252837F for ; Wed, 30 Nov 2016 06:52:30 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 996932838D; Wed, 30 Nov 2016 06:52:30 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 29B4D2838D for ; Wed, 30 Nov 2016 06:52:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756497AbcK3Gw3 (ORCPT ); Wed, 30 Nov 2016 01:52:29 -0500 Received: from ozlabs.ru ([83.169.36.222]:37918 "EHLO ozlabs.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756463AbcK3Gw1 (ORCPT ); Wed, 30 Nov 2016 01:52:27 -0500 Received: from vpl2.ozlabs.ibm.com (localhost [IPv6:::1]) by ozlabs.ru (Postfix) with ESMTP id CBB04120E3D; Wed, 30 Nov 2016 07:52:22 +0100 (CET) From: Alexey Kardashevskiy To: linuxppc-dev@lists.ozlabs.org Cc: Alexey Kardashevskiy , Alex Williamson , David Gibson , Paul Mackerras , kvm@vger.kernel.org Subject: [PATCH kernel v7 5/7] vfio/spapr: Postpone default window creation Date: Wed, 30 Nov 2016 17:52:03 +1100 Message-Id: <1480488725-12783-6-git-send-email-aik@ozlabs.ru> X-Mailer: git-send-email 2.5.0.rc3 In-Reply-To: <1480488725-12783-1-git-send-email-aik@ozlabs.ru> References: <1480488725-12783-1-git-send-email-aik@ozlabs.ru> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP We are going to allow the userspace to configure container in one memory context and pass container fd to another so we are postponing memory allocations accounted against the locked memory limit. One of previous patches took care of it_userspace. At the moment we create the default DMA window when the first group is attached to a container; this is done for the userspace which is not DDW-aware but familiar with the SPAPR TCE IOMMU v2 in the part of memory pre-registration - such client expects the default DMA window to exist. This postpones the default DMA window allocation till one of the folliwing happens: 1. first map/unmap request arrives; 2. new window is requested; This adds noop for the case when the userspace requested removal of the default window which has not been created yet. Signed-off-by: Alexey Kardashevskiy Reviewed-by: David Gibson Acked-by: Alex Williamson --- Changes: v6: * new helper tce_iommu_create_default_window() moved to a separate patch; * creates a default window when new window is requested; it used to reset the def_window_pending flag instead; * def_window_pending handling (mostly) localized in tce_iommu_create_default_window() now, the only exception is removal of not yet created default window. --- drivers/vfio/vfio_iommu_spapr_tce.c | 40 +++++++++++++++++++++++-------------- 1 file changed, 25 insertions(+), 15 deletions(-) diff --git a/drivers/vfio/vfio_iommu_spapr_tce.c b/drivers/vfio/vfio_iommu_spapr_tce.c index a67bbfd..88622be 100644 --- a/drivers/vfio/vfio_iommu_spapr_tce.c +++ b/drivers/vfio/vfio_iommu_spapr_tce.c @@ -97,6 +97,7 @@ struct tce_container { struct mutex lock; bool enabled; bool v2; + bool def_window_pending; unsigned long locked_pages; struct iommu_table *tables[IOMMU_TABLE_GROUP_MAX_TABLES]; struct list_head group_list; @@ -717,6 +718,9 @@ static long tce_iommu_create_default_window(struct tce_container *container) struct tce_iommu_group *tcegrp; struct iommu_table_group *table_group; + if (!container->def_window_pending) + return 0; + if (!tce_groups_attached(container)) return -ENODEV; @@ -730,6 +734,9 @@ static long tce_iommu_create_default_window(struct tce_container *container) table_group->tce32_size, 1, &start_addr); WARN_ON_ONCE(!ret && start_addr); + if (!ret) + container->def_window_pending = false; + return ret; } @@ -823,6 +830,10 @@ static long tce_iommu_ioctl(void *iommu_data, VFIO_DMA_MAP_FLAG_WRITE)) return -EINVAL; + ret = tce_iommu_create_default_window(container); + if (ret) + return ret; + num = tce_iommu_find_table(container, param.iova, &tbl); if (num < 0) return -ENXIO; @@ -886,6 +897,10 @@ static long tce_iommu_ioctl(void *iommu_data, if (param.flags) return -EINVAL; + ret = tce_iommu_create_default_window(container); + if (ret) + return ret; + num = tce_iommu_find_table(container, param.iova, &tbl); if (num < 0) return -ENXIO; @@ -1012,6 +1027,10 @@ static long tce_iommu_ioctl(void *iommu_data, mutex_lock(&container->lock); + ret = tce_iommu_create_default_window(container); + if (ret) + return ret; + ret = tce_iommu_create_window(container, create.page_shift, create.window_size, create.levels, &create.start_addr); @@ -1044,6 +1063,11 @@ static long tce_iommu_ioctl(void *iommu_data, if (remove.flags) return -EINVAL; + if (container->def_window_pending && !remove.start_addr) { + container->def_window_pending = false; + return 0; + } + mutex_lock(&container->lock); ret = tce_iommu_remove_window(container, remove.start_addr); @@ -1141,7 +1165,6 @@ 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); @@ -1189,25 +1212,12 @@ static int tce_iommu_attach_group(void *iommu_data, } else { ret = tce_iommu_take_ownership_ddw(container, table_group); if (!tce_groups_attached(container) && !container->tables[0]) - create_default_window = true; + container->def_window_pending = 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: