From patchwork Tue Aug 4 13:42:01 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Durrant X-Patchwork-Id: 11700405 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D12FF722 for ; Tue, 4 Aug 2020 13:43:23 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id BFAE82075D for ; Tue, 4 Aug 2020 13:43:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=xen.org header.i=@xen.org header.b="FUi5xDky" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BFAE82075D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=xen.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1k2xD9-0008SC-GA; Tue, 04 Aug 2020 13:42:35 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1k2xD8-0008MU-L1 for xen-devel@lists.xenproject.org; Tue, 04 Aug 2020 13:42:34 +0000 X-Inumbo-ID: 678af935-6a4c-4f6c-b259-9e4c468680e6 Received: from mail.xenproject.org (unknown [104.130.215.37]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 678af935-6a4c-4f6c-b259-9e4c468680e6; Tue, 04 Aug 2020 13:42:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=xen.org; s=20200302mail; h=Content-Transfer-Encoding:MIME-Version:References: In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=tvDh3hWaZXavS9k/pMM3gTVqpPl5TsT49cdKXt8Ayaw=; b=FUi5xDkywTwxbeu4EQ+TWeByJU DFIE4zRgO0WPsnhHLHpaARytYJ3cFxUOvnL0S8tgK+J/P2yud3kl+9RI22AfY/FowSMHRHj4xAhKj eifOysnDzItFNeHKZjywM6yB0o9M5DNNVLBBUD+z3nZcmEx1/nksqBRuD9Aw3PLQ3IKU=; Received: from xenbits.xenproject.org ([104.239.192.120]) by mail.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1k2xCu-00084P-MD; Tue, 04 Aug 2020 13:42:20 +0000 Received: from host86-143-223-30.range86-143.btcentralplus.com ([86.143.223.30] helo=u2f063a87eabd5f.home) by xenbits.xenproject.org with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1k2xCu-0003ag-Ef; Tue, 04 Aug 2020 13:42:20 +0000 From: Paul Durrant To: xen-devel@lists.xenproject.org Subject: [PATCH v4 06/14] iommu: flush I/O TLB if iommu_map() or iommu_unmap() fail Date: Tue, 4 Aug 2020 14:42:01 +0100 Message-Id: <20200804134209.8717-7-paul@xen.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200804134209.8717-1-paul@xen.org> References: <20200804134209.8717-1-paul@xen.org> MIME-Version: 1.0 X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Paul Durrant , Jan Beulich Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" From: Paul Durrant This patch adds a full I/O TLB flush to the error paths of iommu_map() and iommu_unmap(). Without this change callers need constructs such as: rc = iommu_map/unmap(...) err = iommu_flush(...) if ( !rc ) rc = err; With this change, it can be simplified to: rc = iommu_map/unmap(...) if ( !rc ) rc = iommu_flush(...) because, if the map or unmap fails the flush will be unnecessary. This saves a stack variable and generally makes the call sites tidier. Signed-off-by: Paul Durrant --- Cc: Jan Beulich v2: - New in v2 --- xen/drivers/passthrough/iommu.c | 28 ++++++++++++---------------- 1 file changed, 12 insertions(+), 16 deletions(-) diff --git a/xen/drivers/passthrough/iommu.c b/xen/drivers/passthrough/iommu.c index 660dc5deb2..e2c0193a09 100644 --- a/xen/drivers/passthrough/iommu.c +++ b/xen/drivers/passthrough/iommu.c @@ -274,6 +274,10 @@ int iommu_map(struct domain *d, dfn_t dfn, mfn_t mfn, break; } + /* Something went wrong so flush everything and clear flush flags */ + if ( unlikely(rc) && iommu_iotlb_flush_all(d, *flush_flags) ) + flush_flags = 0; + return rc; } @@ -283,14 +287,8 @@ int iommu_legacy_map(struct domain *d, dfn_t dfn, mfn_t mfn, unsigned int flush_flags = 0; int rc = iommu_map(d, dfn, mfn, page_order, flags, &flush_flags); - if ( !this_cpu(iommu_dont_flush_iotlb) ) - { - int err = iommu_iotlb_flush(d, dfn, (1u << page_order), - flush_flags); - - if ( !rc ) - rc = err; - } + if ( !this_cpu(iommu_dont_flush_iotlb) && !rc ) + rc = iommu_iotlb_flush(d, dfn, (1u << page_order), flush_flags); return rc; } @@ -330,6 +328,10 @@ int iommu_unmap(struct domain *d, dfn_t dfn, unsigned int page_order, } } + /* Something went wrong so flush everything and clear flush flags */ + if ( unlikely(rc) && iommu_iotlb_flush_all(d, *flush_flags) ) + flush_flags = 0; + return rc; } @@ -338,14 +340,8 @@ int iommu_legacy_unmap(struct domain *d, dfn_t dfn, unsigned int page_order) unsigned int flush_flags = 0; int rc = iommu_unmap(d, dfn, page_order, &flush_flags); - if ( !this_cpu(iommu_dont_flush_iotlb) ) - { - int err = iommu_iotlb_flush(d, dfn, (1u << page_order), - flush_flags); - - if ( !rc ) - rc = err; - } + if ( !this_cpu(iommu_dont_flush_iotlb) && ! rc ) + rc = iommu_iotlb_flush(d, dfn, (1u << page_order), flush_flags); return rc; }