From patchwork Mon Dec 16 20:21:40 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kirti Wankhede X-Patchwork-Id: 11295259 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 822C7138D for ; Mon, 16 Dec 2019 20:51:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5EE3621835 for ; Mon, 16 Dec 2019 20:51:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="XGZ7gJUz" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727036AbfLPUvF (ORCPT ); Mon, 16 Dec 2019 15:51:05 -0500 Received: from hqnvemgate24.nvidia.com ([216.228.121.143]:5866 "EHLO hqnvemgate24.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726968AbfLPUvF (ORCPT ); Mon, 16 Dec 2019 15:51:05 -0500 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate24.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Mon, 16 Dec 2019 12:50:36 -0800 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Mon, 16 Dec 2019 12:51:03 -0800 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Mon, 16 Dec 2019 12:51:03 -0800 Received: from HQMAIL105.nvidia.com (172.20.187.12) by HQMAIL111.nvidia.com (172.20.187.18) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Mon, 16 Dec 2019 20:51:03 +0000 Received: from kwankhede-dev.nvidia.com (10.124.1.5) by HQMAIL105.nvidia.com (172.20.187.12) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Mon, 16 Dec 2019 20:50:56 +0000 From: Kirti Wankhede To: , CC: , , , , , , , , , , , , , , , , , , , , "Kirti Wankhede" Subject: [PATCH v10 Kernel 5/5] vfio iommu: Update UNMAP_DMA ioctl to get dirty bitmap before unmap Date: Tue, 17 Dec 2019 01:51:40 +0530 Message-ID: <1576527700-21805-6-git-send-email-kwankhede@nvidia.com> X-Mailer: git-send-email 2.7.0 In-Reply-To: <1576527700-21805-1-git-send-email-kwankhede@nvidia.com> References: <1576527700-21805-1-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=1576529436; bh=NNfqr2vUhNMQwsoU1oTVwnAsTm+8VgO1yNM6gGnpjxc=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:X-NVConfidentiality:MIME-Version: Content-Type; b=XGZ7gJUzDah5hAW2zBOzjQIgCrmSRUqOv5Zoql4ICJJKs5yofezjm2WLCvRbxv5NA eEUGuiMazXvHc+lLKVofeuqLC8mSE05rvGrMxLAtx/T+tmKfVARt3nkCJML6cmbwfl B366mYSqSzilheVexJiQX3Q9+3sPF0XTf0HmdJ6s2jNAcunhlQ94E2fRCE5iHD7dcQ mLpmyTaLxbouRjSqVnxBS+Xn5wSnfjL5t0uS6JllpbRbMgi7zCS9tKvAZpDzH4t//1 eOBulKWA/vzCUYxJ4zw9NbYeOuuZX+tr5HXfvLHYkUVVJw/nHSWaKTtoJ514JdzDQA 5PuIJdkwAjKSQ== 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 | 63 ++++++++++++++++++++++++++++++++++++----- include/uapi/linux/vfio.h | 12 ++++++++ 2 files changed, 68 insertions(+), 7 deletions(-) diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index 264449654d3f..6bd02a13903b 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -970,7 +970,8 @@ 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; @@ -1045,6 +1046,15 @@ 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, unmap->iova, + bitmap); + else + vfio_remove_unpinned_from_pfn_list(dma, true); + + if (!RB_EMPTY_ROOT(&dma->pfn_list)) { struct vfio_iommu_type1_dma_unmap nb_unmap; @@ -1070,6 +1080,7 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu, &nb_unmap); goto again; } + unmapped += dma->size; vfio_remove_dma(iommu, dma); } @@ -2401,22 +2412,60 @@ 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)) + if (copy_from_user(&unmap, (void __user *)arg, sizeof(unmap))) 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 = __ffs(unmap.bitmap_pgsize); + uint64_t iommu_pgmask = + ((uint64_t)1 << __ffs(vfio_pgsize_bitmap(iommu))) - 1; + + if (((unmap.bitmap_pgsize - 1) & iommu_pgmask) != + (unmap.bitmap_pgsize - 1)) + return -EINVAL; + + bsize = verify_bitmap_size(unmap.size >> pgshift, + unmap.bitmap_size); + if (bsize < 0) + return bsize; + + bitmap = kmalloc(bsize, GFP_KERNEL); + if (!bitmap) + return -ENOMEM; + + if (copy_from_user(bitmap, (void __user *)unmap.bitmap, + bsize)) { + ret = -EFAULT; + goto unmap_exit; + } + } + + ret = vfio_dma_do_unmap(iommu, &unmap, bitmap); if (ret) - return ret; + goto unmap_exit; - return copy_to_user((void __user *)arg, &unmap, minsz) ? + if (unmap.flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) { + if (copy_to_user((void __user *)unmap.bitmap, bitmap, + bsize)) { + ret = -EFAULT; + goto unmap_exit; + } + } + + ret = copy_to_user((void __user *)arg, &unmap, minsz) ? -EFAULT : 0; +unmap_exit: + kfree(bitmap); + 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 4ad54fbb4698..7705aea7bdaf 100644 --- a/include/uapi/linux/vfio.h +++ b/include/uapi/linux/vfio.h @@ -958,12 +958,24 @@ 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)