From patchwork Wed Dec 28 21:32:12 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shachar Raindel X-Patchwork-Id: 13083212 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 89033C4332F for ; Wed, 28 Dec 2022 21:33:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232147AbiL1VdI (ORCPT ); Wed, 28 Dec 2022 16:33:08 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42150 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230406AbiL1VdG (ORCPT ); Wed, 28 Dec 2022 16:33:06 -0500 Received: from mail-qk1-x749.google.com (mail-qk1-x749.google.com [IPv6:2607:f8b0:4864:20::749]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0D1E7140C8 for ; Wed, 28 Dec 2022 13:33:02 -0800 (PST) Received: by mail-qk1-x749.google.com with SMTP id i4-20020a05620a248400b006febc1651bbso11743419qkn.4 for ; Wed, 28 Dec 2022 13:33:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=IL2YbOoN7yPmIShOQbEFF8vOUsSkAn/M3lJ9txKjS40=; b=DQd928Kdr25J4ElaX6WZIg0y5aPMxnpaZIJg7IPsyFdp7Z3sU095SY0P4pr93F+joX xUOk7tHxITprNKxjOzKUe37tbXK/nCU27n9rSpuQq1RpZsLqxdkYR8J3rkdvDie+cd+y ICbF0Bb4zALDvouCsj8CQka5kHUqA+uGamn/b8vdYyT2UPKCSqXq3xcLHVYsCFJ49nfE DEiCH87vUImae/stFU5wBLHDK0H2wgLqT9wzF1M2QF/ObcdX/Z82QE3LEsX8T45STvmL D1V14FdeAMzvVu4ud311bpNBF3CP3ub9xaQlueCFvMG89KPT/0ILIL398AEZfuEQs4Zg I1rQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=IL2YbOoN7yPmIShOQbEFF8vOUsSkAn/M3lJ9txKjS40=; b=otI9CYQ/Q7Ja6kv8IN1A8CG3et6VmveReaGX9W8Dz/dpbj5j20ycntuOlCUIRuJskv 1USZyalfSlOJ2AV8qYj0qZqKcmYbaID+6F/0a5ajw4Z/+w9GRvnfQB+frGIXe44awkqP 8lWfSxKwv2shVtVpvT499S1RwaXy3ije8ytny/nlx718Q2l4zEGgC135lPfGCcpmDNwC fqcwS2WHE9+XgYgviY5eQYMvLkPiC862jy9bQuefnaAsO8NL4BbbLlcK/zL91lVrvXPY TCtc+7ewnmQRBcK6N1ckQGiwpXxsIuycgMMJmSAKd5q4J42lGHFJ00I3B/NUxZUsmLoY gp8Q== X-Gm-Message-State: AFqh2kpn+DXhgjkTdTCXEwFibeFXcggwmKa+YHZce1bWDzcwqgnSLpxv b/BqLBj7VgIIYtb7usz5dfCroeic1AoXHQ== X-Google-Smtp-Source: AMrXdXuT3YZ7pyxLMjotm+dwHDwO4EFMSgwCmbIC0SCzzCpxPS24vC4Udc+/ecWzG0atJluAdQBMxnC4sffFuA== X-Received: from shacharr-cloud.c.googlers.com ([fda3:e722:ac3:cc00:2b:7d90:c0a8:4338]) (user=shacharr job=sendgmr) by 2002:a0c:e991:0:b0:530:eae2:9240 with SMTP id z17-20020a0ce991000000b00530eae29240mr750777qvn.106.1672263181304; Wed, 28 Dec 2022 13:33:01 -0800 (PST) Date: Wed, 28 Dec 2022 21:32:12 +0000 Mime-Version: 1.0 X-Mailer: git-send-email 2.39.0.314.g84b9a713c41-goog Message-ID: <20221228213212.628636-1-shacharr@google.com> Subject: [PATCH] Convert backwards goto into a while loop From: Shachar Raindel To: Alex Williamson , Cornelia Huck Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Shachar Raindel Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org The function vaddr_get_pfns used a goto retry structure to implement retrying. This is discouraged by the coding style guide (which is only recommending goto for handling function exits). Convert the code to a while loop, making it explicit that the follow block only runs when the pin attempt failed. Signed-off-by: Shachar Raindel --- drivers/vfio/vfio_iommu_type1.c | 27 ++++++++++++++------------- 1 file changed, 14 insertions(+), 13 deletions(-) diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index 23c24fe98c00..7f38d7fc3f62 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -570,27 +570,28 @@ static int vaddr_get_pfns(struct mm_struct *mm, unsigned long vaddr, } *pfn = page_to_pfn(pages[0]); - goto done; - } + } else + do { + + /* This is not a normal page, lookup PFN for P2P DMA */ + vaddr = untagged_addr(vaddr); - vaddr = untagged_addr(vaddr); + vma = vma_lookup(mm, vaddr); -retry: - vma = vma_lookup(mm, vaddr); + if (!vma || !(vma->vm_flags & VM_PFNMAP)) + break; - if (vma && vma->vm_flags & VM_PFNMAP) { - ret = follow_fault_pfn(vma, mm, vaddr, pfn, prot & IOMMU_WRITE); - if (ret == -EAGAIN) - goto retry; + ret = follow_fault_pfn(vma, mm, vaddr, pfn, + prot & IOMMU_WRITE); + if (ret) + continue; /* Retry for EAGAIN, otherwise bail */ - if (!ret) { if (is_invalid_reserved_pfn(*pfn)) ret = 1; else ret = -EFAULT; - } - } -done: + } while (ret == -EAGAIN); + mmap_read_unlock(mm); return ret; }