From patchwork Fri Feb 7 19:42:32 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kirti Wankhede X-Patchwork-Id: 11371115 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 9AA9C14E3 for ; Fri, 7 Feb 2020 20:16:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 79E6F214AF for ; Fri, 7 Feb 2020 20:16:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="GtSH+4YW" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727516AbgBGUQz (ORCPT ); Fri, 7 Feb 2020 15:16:55 -0500 Received: from hqnvemgate26.nvidia.com ([216.228.121.65]:11723 "EHLO hqnvemgate26.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727473AbgBGUQy (ORCPT ); Fri, 7 Feb 2020 15:16:54 -0500 Received: from hqpgpgate102.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate26.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Fri, 07 Feb 2020 12:16:38 -0800 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate102.nvidia.com (PGP Universal service); Fri, 07 Feb 2020 12:16:52 -0800 X-PGP-Universal: processed; by hqpgpgate102.nvidia.com on Fri, 07 Feb 2020 12:16:52 -0800 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; Fri, 7 Feb 2020 20:16:53 +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; Fri, 7 Feb 2020 20:16:46 +0000 From: Kirti Wankhede To: , CC: , , , , , , , , , , , , , , , , , , , , "Kirti Wankhede" Subject: [PATCH v12 Kernel 5/7] vfio iommu: Update UNMAP_DMA ioctl to get dirty bitmap before unmap Date: Sat, 8 Feb 2020 01:12:32 +0530 Message-ID: <1581104554-10704-6-git-send-email-kwankhede@nvidia.com> X-Mailer: git-send-email 2.7.0 In-Reply-To: <1581104554-10704-1-git-send-email-kwankhede@nvidia.com> References: <1581104554-10704-1-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=1581106598; bh=aoFkyD1phMFO3EyRxvdVkmH6qXD9Mf9B75hip54fN0Q=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:X-NVConfidentiality:MIME-Version: Content-Type; b=GtSH+4YWZQks9jV6N6Ltj9EXGfVEknP+F7FINzaLjVOaU9hf9a/QqktY/t994Fu0+ 7UlSggffbI9bu6AlEOWceSBxEEjBgTVZ33mdYsWb+0BaFZdENtmYchxWi6qjJfBkPT IvPPJ4gX2jyfg12kg4NqwtbzwVG4lNtZNd6ffbSiHz/ypITzji01BXcp685BC7ao9f YMVnUiti4hRUjcGwt8eIboClQC1CjVZjqL305TWK3/DjmZ7Fs+B0Bf7aIXTBpTZxe2 NllIZkCTTxM3T9XuT4Ei+9XAZUHnuOECw5Wa6E+FZKd5+8/0gmVtE5kQkvcKsnx3sa ZJ4yDrO7p6h3g== Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Pages, pinned by external interface for requested IO virtual address range, might get unpinned and unmapped while migration is active and device is still running, that is, in pre-copy phase while guest driver still could access those pages. Host device can write to these pages while those were mapped. Such pages should be marked dirty so that after migration guest driver should still be able to complete the operation. 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 | 56 +++++++++++++++++++++++++++++++++++++---- include/uapi/linux/vfio.h | 12 +++++++++ 2 files changed, 63 insertions(+), 5 deletions(-) diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index df358dc1c85b..4e6ad0513932 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -1032,7 +1032,8 @@ static long verify_bitmap_size(unsigned long npages, unsigned long 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, + unsigned long *bitmap) { uint64_t mask; struct vfio_dma *dma, *dma_last = NULL; @@ -1107,6 +1108,15 @@ 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) && + (dma_last != dma)) + vfio_iova_dirty_bitmap(iommu, dma->iova, dma->size, + unmap->bitmap_pgsize, + (unsigned char __user *) bitmap); + else + vfio_remove_unpinned_from_pfn_list(dma); + + if (!RB_EMPTY_ROOT(&dma->pfn_list)) { struct vfio_iommu_type1_dma_unmap nb_unmap; @@ -1132,6 +1142,7 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu, &nb_unmap); goto again; } + unmapped += dma->size; vfio_remove_dma(iommu, dma); } @@ -2462,22 +2473,57 @@ 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; + unsigned long *bitmap = NULL; + long ret, bsize; 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_pgsizes = vfio_pgsize_bitmap(iommu); + uint64_t iommu_pgmask = + ((uint64_t)1 << __ffs(iommu_pgsizes)) - 1; + + if (copy_from_user(&unmap, (void __user *)arg, + sizeof(unmap))) + return -EFAULT; + + pgshift = __ffs(unmap.bitmap_pgsize); + + if (((unmap.bitmap_pgsize - 1) & iommu_pgmask) != + (unmap.bitmap_pgsize - 1)) + return -EINVAL; + + if ((unmap.bitmap_pgsize & iommu_pgsizes) != + unmap.bitmap_pgsize) + return -EINVAL; + if (unmap.iova + unmap.size < unmap.iova) + return -EINVAL; + if (!access_ok((void __user *)unmap.bitmap, + unmap.bitmap_size)) + return -EINVAL; + + bsize = verify_bitmap_size(unmap.size >> pgshift, + unmap.bitmap_size); + if (bsize < 0) + return bsize; + bitmap = unmap.bitmap; + } + + ret = vfio_dma_do_unmap(iommu, &unmap, bitmap); if (ret) return ret; - return copy_to_user((void __user *)arg, &unmap, minsz) ? + ret = copy_to_user((void __user *)arg, &unmap, minsz) ? -EFAULT : 0; + return ret; } else if (cmd == VFIO_IOMMU_DIRTY_PAGES) { struct vfio_iommu_type1_dirty_bitmap range; uint32_t mask = VFIO_IOMMU_DIRTY_PAGES_FLAG_START | diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h index b1b03c720749..a852e729b5a2 100644 --- a/include/uapi/linux/vfio.h +++ b/include/uapi/linux/vfio.h @@ -985,12 +985,24 @@ struct vfio_iommu_type1_dma_map { * 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 should + * allocate memory to get bitmap, clear the bitmap memory by setting zero and + * should set size of allocated memory in bitmap_size field. One bit in bitmap + * represents per page , page of user provided page size in 'bitmap_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 bitmap. */ 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) */ + __u64 bitmap_pgsize; /* page size for bitmap */ + __u64 bitmap_size; /* in bytes */ + void __user *bitmap; /* one bit per page */ }; #define VFIO_IOMMU_UNMAP_DMA _IO(VFIO_TYPE, VFIO_BASE + 14)