From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B1E04C4332B for ; Thu, 7 Jan 2021 09:30:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 73A9B2333F for ; Thu, 7 Jan 2021 09:30:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727857AbhAGJac (ORCPT ); Thu, 7 Jan 2021 04:30:32 -0500 Received: from szxga05-in.huawei.com ([45.249.212.191]:10556 "EHLO szxga05-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727785AbhAGJab (ORCPT ); Thu, 7 Jan 2021 04:30:31 -0500 Received: from DGGEMS404-HUB.china.huawei.com (unknown [172.30.72.60]) by szxga05-in.huawei.com (SkyGuard) with ESMTP id 4DBLWb5xgWzMGSd; Thu, 7 Jan 2021 17:28:27 +0800 (CST) Received: from DESKTOP-5IS4806.china.huawei.com (10.174.184.42) by DGGEMS404-HUB.china.huawei.com (10.3.19.204) with Microsoft SMTP Server id 14.3.498.0; Thu, 7 Jan 2021 17:29:29 +0800 From: Keqian Zhu To: , , , , , Alex Williamson , Kirti Wankhede , Cornelia Huck , Will Deacon , Marc Zyngier , Catalin Marinas CC: Mark Rutland , James Morse , Robin Murphy , Joerg Roedel , "Daniel Lezcano" , Thomas Gleixner , Suzuki K Poulose , Julien Thierry , Andrew Morton , Alexios Zavras , , Subject: [PATCH 1/5] vfio/iommu_type1: Fixes vfio_dma_populate_bitmap to avoid dirty lose Date: Thu, 7 Jan 2021 17:28:57 +0800 Message-ID: <20210107092901.19712-2-zhukeqian1@huawei.com> X-Mailer: git-send-email 2.8.4.windows.1 In-Reply-To: <20210107092901.19712-1-zhukeqian1@huawei.com> References: <20210107092901.19712-1-zhukeqian1@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.174.184.42] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Defer checking whether vfio_dma is of fully-dirty in update_user_bitmap is easy to lose dirty log. For example, after promoting pinned_scope of vfio_iommu, vfio_dma is not considered as fully-dirty, then we may lose dirty log that occurs before vfio_iommu is promoted. The key point is that pinned-dirty is not a real dirty tracking way, it can't continuously track dirty pages, but just restrict dirty scope. It is essentially the same as fully-dirty. Fully-dirty is of full-scope and pinned-dirty is of pinned-scope. So we must mark pinned-dirty or fully-dirty after we start dirty tracking or clear dirty bitmap, to ensure that dirty log is marked right away. Fixes: d6a4c185660c ("vfio iommu: Implementation of ioctl for dirty pages tracking") Signed-off-by: Keqian Zhu --- drivers/vfio/vfio_iommu_type1.c | 33 ++++++++++++++++++++++----------- 1 file changed, 22 insertions(+), 11 deletions(-) diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index bceda5e8baaa..b0a26e8e0adf 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -224,7 +224,7 @@ static void vfio_dma_bitmap_free(struct vfio_dma *dma) dma->bitmap = NULL; } -static void vfio_dma_populate_bitmap(struct vfio_dma *dma, size_t pgsize) +static void vfio_dma_populate_bitmap_pinned(struct vfio_dma *dma, size_t pgsize) { struct rb_node *p; unsigned long pgshift = __ffs(pgsize); @@ -236,6 +236,25 @@ static void vfio_dma_populate_bitmap(struct vfio_dma *dma, size_t pgsize) } } +static void vfio_dma_populate_bitmap_full(struct vfio_dma *dma, size_t pgsize) +{ + unsigned long pgshift = __ffs(pgsize); + unsigned long nbits = dma->size >> pgshift; + + bitmap_set(dma->bitmap, 0, nbits); +} + +static void vfio_dma_populate_bitmap(struct vfio_iommu *iommu, + struct vfio_dma *dma) +{ + size_t pgsize = (size_t)1 << __ffs(iommu->pgsize_bitmap); + + if (iommu->pinned_page_dirty_scope) + vfio_dma_populate_bitmap_pinned(dma, pgsize); + else if (dma->iommu_mapped) + vfio_dma_populate_bitmap_full(dma, pgsize); +} + static int vfio_dma_bitmap_alloc_all(struct vfio_iommu *iommu) { struct rb_node *n; @@ -257,7 +276,7 @@ static int vfio_dma_bitmap_alloc_all(struct vfio_iommu *iommu) } return ret; } - vfio_dma_populate_bitmap(dma, pgsize); + vfio_dma_populate_bitmap(iommu, dma); } return 0; } @@ -987,13 +1006,6 @@ static int update_user_bitmap(u64 __user *bitmap, struct vfio_iommu *iommu, unsigned long shift = bit_offset % BITS_PER_LONG; unsigned long leftover; - /* - * mark all pages dirty if any IOMMU capable device is not able - * to report dirty pages and all pages are pinned and mapped. - */ - if (!iommu->pinned_page_dirty_scope && dma->iommu_mapped) - bitmap_set(dma->bitmap, 0, nbits); - if (shift) { bitmap_shift_left(dma->bitmap, dma->bitmap, shift, nbits + shift); @@ -1019,7 +1031,6 @@ static int vfio_iova_dirty_bitmap(u64 __user *bitmap, struct vfio_iommu *iommu, struct vfio_dma *dma; struct rb_node *n; unsigned long pgshift = __ffs(iommu->pgsize_bitmap); - size_t pgsize = (size_t)1 << pgshift; int ret; /* @@ -1055,7 +1066,7 @@ static int vfio_iova_dirty_bitmap(u64 __user *bitmap, struct vfio_iommu *iommu, * pages which are marked dirty by vfio_dma_rw() */ bitmap_clear(dma->bitmap, 0, dma->size >> pgshift); - vfio_dma_populate_bitmap(dma, pgsize); + vfio_dma_populate_bitmap(iommu, dma); } return 0; } -- 2.19.1