From patchwork Mon Feb 11 07:49:17 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexey Kardashevskiy X-Patchwork-Id: 1039685 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 43ydKJ1MdYz9sBZ for ; Mon, 11 Feb 2019 18:51:48 +1100 (AEDT) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=ozlabs.ru Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 43ydKH6Y8BzDqMs for ; Mon, 11 Feb 2019 18:51:47 +1100 (AEDT) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=ozlabs.ru (client-ip=107.173.13.209; helo=ozlabs.ru; envelope-from=aik@ozlabs.ru; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=ozlabs.ru Received: from ozlabs.ru (ozlabs.ru [107.173.13.209]) by lists.ozlabs.org (Postfix) with ESMTP id 43ydGV3mx8zDqNC for ; Mon, 11 Feb 2019 18:49:22 +1100 (AEDT) Received: from fstn1-p1.ozlabs.ibm.com (localhost [IPv6:::1]) by ozlabs.ru (Postfix) with ESMTP id 59F58AE80013; Mon, 11 Feb 2019 02:49:19 -0500 (EST) From: Alexey Kardashevskiy To: linuxppc-dev@lists.ozlabs.org Subject: [PATCH kernel] vfio/spapr_tce: Skip unsetting already unset table Date: Mon, 11 Feb 2019 18:49:17 +1100 Message-Id: <20190211074917.125723-1-aik@ozlabs.ru> X-Mailer: git-send-email 2.17.1 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Alexey Kardashevskiy , Alex Williamson , kvm@vger.kernel.org, kvm-ppc@vger.kernel.org, David Gibson Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" VFIO TCE IOMMU v2 owns IOMMU tables so when detach a IOMMU group from a container, we need to unset those from a group so we call unset_window() so do we unconditionally. We also unset tables when removing a DMA window via the VFIO_IOMMU_SPAPR_TCE_REMOVE ioctl. The window removal checks if the table actually exists (hidden inside tce_iommu_find_table()) but the group detaching does not so the user may see duplicating messages: pci 0009:03 : [PE# fd] Removing DMA window #0 pci 0009:03 : [PE# fd] Removing DMA window #1 pci 0009:03 : [PE# fd] Removing DMA window #0 pci 0009:03 : [PE# fd] Removing DMA window #1 At the moment this is not a problem as the second invocation of unset_window() writes zeroes to the HW registers again and exits early as there is no table. Signed-off-by: Alexey Kardashevskiy Reviewed-by: David Gibson --- When doing VFIO PCI hot unplug, first we remove the DMA window and set container->tables[num] - this is a first couple of messages. Then we detach the group and then we see another couple of the same messages which confused myself. --- drivers/vfio/vfio_iommu_spapr_tce.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/vfio/vfio_iommu_spapr_tce.c b/drivers/vfio/vfio_iommu_spapr_tce.c index c424913..8dbb270 100644 --- a/drivers/vfio/vfio_iommu_spapr_tce.c +++ b/drivers/vfio/vfio_iommu_spapr_tce.c @@ -1235,7 +1235,8 @@ static void tce_iommu_release_ownership_ddw(struct tce_container *container, } for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) - table_group->ops->unset_window(table_group, i); + if (container->tables[i]) + table_group->ops->unset_window(table_group, i); table_group->ops->release_ownership(table_group); }