From patchwork Wed Mar 18 19:41:12 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kirti Wankhede X-Patchwork-Id: 11445889 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 E8B2A159A for ; Wed, 18 Mar 2020 20:15:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C00512077A for ; Wed, 18 Mar 2020 20:15:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="RcskkHvY" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727025AbgCRUPZ (ORCPT ); Wed, 18 Mar 2020 16:15:25 -0400 Received: from hqnvemgate24.nvidia.com ([216.228.121.143]:11712 "EHLO hqnvemgate24.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726647AbgCRUPY (ORCPT ); Wed, 18 Mar 2020 16:15:24 -0400 Received: from hqpgpgate102.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate24.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Wed, 18 Mar 2020 13:13:42 -0700 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate102.nvidia.com (PGP Universal service); Wed, 18 Mar 2020 13:15:19 -0700 X-PGP-Universal: processed; by hqpgpgate102.nvidia.com on Wed, 18 Mar 2020 13:15:19 -0700 Received: from HQMAIL101.nvidia.com (172.20.187.10) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Wed, 18 Mar 2020 20:15:19 +0000 Received: from kwankhede-dev.nvidia.com (10.124.1.5) by HQMAIL101.nvidia.com (172.20.187.10) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Wed, 18 Mar 2020 20:15:13 +0000 From: Kirti Wankhede To: , CC: , , , , , , , , , , , , , , , , , , , , "Kirti Wankhede" Subject: [PATCH v14 Kernel 5/7] vfio iommu: Update UNMAP_DMA ioctl to get dirty bitmap before unmap Date: Thu, 19 Mar 2020 01:11:12 +0530 Message-ID: <1584560474-19946-6-git-send-email-kwankhede@nvidia.com> X-Mailer: git-send-email 2.7.0 In-Reply-To: <1584560474-19946-1-git-send-email-kwankhede@nvidia.com> References: <1584560474-19946-1-git-send-email-kwankhede@nvidia.com> X-NVConfidentiality: public MIME-Version: 1.0 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1584562422; bh=aWL3NYVL/GSFI1ikQbEz6sngDR9QJ7L8SkHu4mkwBkk=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:X-NVConfidentiality:MIME-Version: Content-Type; b=RcskkHvYc5uMC0m0aDN00cJb+fQw1OTQhx1vNazWiRbKyLOfo0iJ20Ft2XNZbx5oA LHJyoXrwcA1CngU7X3z3r6W6D33yblYcWXwSdNRqsbmMD/GhSTdBxat2zmQu22t2oa HeEM1Dm0ThZsDtTaYwvY6zG9kg9/dnn3OiwecpsoRJf6LAQSfuwlNHEGG+6G8Sj/r5 BbQ+5/eyXEmMCkEepv7OYyqbLH1VYi0ZxY/wCiNqlDYGxCoHlhzGQ7ZpQSXa3V+G2z AElMWDjTHy7EG2iD7ZmEhb/Clw7M2KoWPcag/CufrdOQD0TTd3Cv3F36FOxpbbRmZz rIwcuu7wjotNw== Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org DMA mapped pages, including those pinned by mdev vendor drivers, might get unpinned and unmapped while migration is active and device is still running. For example, in pre-copy phase while guest driver could access those pages, host device or vendor driver can dirty these mapped pages. Such pages should be marked dirty so as to maintain memory consistency for a user making use of dirty page tracking. To get bitmap during unmap, user should set flag VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP, bitmap memory should be allocated and zeroed by user space application. Bitmap size and page size should be set by user application. Signed-off-by: Kirti Wankhede Reviewed-by: Neo Jia --- drivers/vfio/vfio_iommu_type1.c | 55 ++++++++++++++++++++++++++++++++++++++--- include/uapi/linux/vfio.h | 11 +++++++++ 2 files changed, 62 insertions(+), 4 deletions(-) diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index d6417fb02174..aa1ac30f7854 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -939,7 +939,8 @@ static int verify_bitmap_size(uint64_t npages, uint64_t bitmap_size) } static int vfio_dma_do_unmap(struct vfio_iommu *iommu, - struct vfio_iommu_type1_dma_unmap *unmap) + struct vfio_iommu_type1_dma_unmap *unmap, + struct vfio_bitmap *bitmap) { uint64_t mask; struct vfio_dma *dma, *dma_last = NULL; @@ -990,6 +991,10 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu, * will be returned if these conditions are not met. The v2 interface * will only return success and a size of zero if there were no * mappings within the range. + * + * When VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP flag is set, unmap request + * must be for single mapping. Multiple mappings with this flag set is + * not supported. */ if (iommu->v2) { dma = vfio_find_dma(iommu, unmap->iova, 1); @@ -997,6 +1002,13 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu, ret = -EINVAL; goto unlock; } + + if ((unmap->flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) && + (dma->iova != unmap->iova || dma->size != unmap->size)) { + ret = -EINVAL; + goto unlock; + } + dma = vfio_find_dma(iommu, unmap->iova + unmap->size - 1, 0); if (dma && dma->iova + dma->size != unmap->iova + unmap->size) { ret = -EINVAL; @@ -1014,6 +1026,12 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu, if (dma->task->mm != current->mm) break; + if ((unmap->flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) && + iommu->dirty_page_tracking) + vfio_iova_dirty_bitmap(iommu, dma->iova, dma->size, + bitmap->pgsize, + (unsigned char __user *) bitmap->data); + if (!RB_EMPTY_ROOT(&dma->pfn_list)) { struct vfio_iommu_type1_dma_unmap nb_unmap; @@ -2369,17 +2387,46 @@ static long vfio_iommu_type1_ioctl(void *iommu_data, } else if (cmd == VFIO_IOMMU_UNMAP_DMA) { struct vfio_iommu_type1_dma_unmap unmap; - long ret; + struct vfio_bitmap bitmap = { 0 }; + int ret; minsz = offsetofend(struct vfio_iommu_type1_dma_unmap, size); if (copy_from_user(&unmap, (void __user *)arg, minsz)) return -EFAULT; - if (unmap.argsz < minsz || unmap.flags) + if (unmap.argsz < minsz || + unmap.flags & ~VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) return -EINVAL; - ret = vfio_dma_do_unmap(iommu, &unmap); + if (unmap.flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) { + unsigned long pgshift; + uint64_t iommu_pgsize = + 1 << __ffs(vfio_pgsize_bitmap(iommu)); + + if (unmap.argsz < (minsz + sizeof(bitmap))) + return -EINVAL; + + if (copy_from_user(&bitmap, + (void __user *)(arg + minsz), + sizeof(bitmap))) + return -EFAULT; + + /* allow only min supported pgsize */ + if (bitmap.pgsize != iommu_pgsize) + return -EINVAL; + if (!access_ok((void __user *)bitmap.data, bitmap.size)) + return -EINVAL; + + pgshift = __ffs(bitmap.pgsize); + ret = verify_bitmap_size(unmap.size >> pgshift, + bitmap.size); + if (ret) + return ret; + + } + + ret = vfio_dma_do_unmap(iommu, &unmap, &bitmap); if (ret) return ret; diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h index 043e9eafb255..a704e5380f04 100644 --- a/include/uapi/linux/vfio.h +++ b/include/uapi/linux/vfio.h @@ -1010,12 +1010,23 @@ struct vfio_bitmap { * field. No guarantee is made to the user that arbitrary unmaps of iova * or size different from those used in the original mapping call will * succeed. + * VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP should be set to get dirty bitmap + * before unmapping IO virtual addresses. When this flag is set, user must + * provide data[] as structure vfio_bitmap. User must allocate memory to get + * bitmap, clear the bitmap memory by setting zero and must set size of + * allocated memory in vfio_bitmap.size field. One bit in bitmap + * represents per page, page of user provided page size in 'pgsize', + * consecutively starting from iova offset. Bit set indicates page at that + * offset from iova is dirty. Bitmap of pages in the range of unmapped size is + * returned in vfio_bitmap.data */ struct vfio_iommu_type1_dma_unmap { __u32 argsz; __u32 flags; +#define VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP (1 << 0) __u64 iova; /* IO virtual address */ __u64 size; /* Size of mapping (bytes) */ + __u8 data[]; }; #define VFIO_IOMMU_UNMAP_DMA _IO(VFIO_TYPE, VFIO_BASE + 14)