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=-6.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 26721C433E0 for ; Wed, 20 May 2020 10:29:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 00F5C207ED for ; Wed, 20 May 2020 10:29:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="etXrbDj9" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726452AbgETK3S (ORCPT ); Wed, 20 May 2020 06:29:18 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:50020 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726224AbgETK3S (ORCPT ); Wed, 20 May 2020 06:29:18 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1589970556; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=j7Qa636nr77ozit91n4CLVmdB0iFZ+gh72rScJACoHw=; b=etXrbDj9JKS4k3dVEj0qJcwOso63JFiLOx88bSoVyX/A9PoAut1ZUXdsiipVIFG5wK9t3i 4ckoTOKjnbCAXudL3uEMbTQvL8lm2ph+/FxA0IpFaU1L4Nv8u7KAXdYAGCj8fOhRN3cKPv d41tVjE+4em1vPsNZJzBG/jvVFJh7l0= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-341-sewPRTkzPD2PrbfB3t4NVg-1; Wed, 20 May 2020 06:29:12 -0400 X-MC-Unique: sewPRTkzPD2PrbfB3t4NVg-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 246C81005510; Wed, 20 May 2020 10:29:10 +0000 (UTC) Received: from gondolin (ovpn-113-5.ams2.redhat.com [10.36.113.5]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9049F1943D; Wed, 20 May 2020 10:29:02 +0000 (UTC) Date: Wed, 20 May 2020 12:27:38 +0200 From: Cornelia Huck To: Kirti Wankhede Cc: , , , , , , , , , , , , , , , , , , , , Subject: Re: [PATCH Kernel v22 6/8] vfio iommu: Update UNMAP_DMA ioctl to get dirty bitmap before unmap Message-ID: <20200520122738.351985a3.cohuck@redhat.com> In-Reply-To: <1589871253-10650-1-git-send-email-kwankhede@nvidia.com> References: <1589781397-28368-7-git-send-email-kwankhede@nvidia.com> <1589871253-10650-1-git-send-email-kwankhede@nvidia.com> Organization: Red Hat GmbH MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Tue, 19 May 2020 12:24:13 +0530 Kirti Wankhede wrote: > 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 allocate memory for bitmap, set > it all zeros, set size of allocated memory, set page size to be > considered for bitmap and set flag VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP. > > Signed-off-by: Kirti Wankhede > Reviewed-by: Neo Jia > --- > drivers/vfio/vfio_iommu_type1.c | 62 +++++++++++++++++++++++++++++++++-------- > include/uapi/linux/vfio.h | 10 +++++++ > 2 files changed, 61 insertions(+), 11 deletions(-) (...) > @@ -1085,6 +1093,7 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu, > ret = -EINVAL; > goto unlock; > } > + Nit: unrelated whitespace change. > dma = vfio_find_dma(iommu, unmap->iova + unmap->size - 1, 0); > if (dma && dma->iova + dma->size != unmap->iova + unmap->size) { > ret = -EINVAL; (...) > diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h > index 4850c1fef1f8..a1dd2150971e 100644 > --- a/include/uapi/linux/vfio.h > +++ b/include/uapi/linux/vfio.h > @@ -1048,12 +1048,22 @@ 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 s/dirty bitmap/the dirty bitmap/ > + * before unmapping IO virtual addresses. When this flag is set, user must s/user/the user/ > + * provide data[] as structure vfio_bitmap. User must allocate memory to get "provide a struct vfio_bitmap in data[]" ? > + * bitmap, zero the bitmap memory and must set size of allocated memory in > + * vfio_bitmap.size field. "The user must provide zero-allocated memory via vfio_bitmap.data and its size in the vfio_bitmap.size field." ? > A bit in bitmap represents one page of user provided s/bitmap/the bitmap/ > + * page size in 'pgsize', consecutively starting from iova offset. Bit set s/Bit set/A set bit/ > + * indicates page at that offset from iova is dirty. Bitmap of pages in the s/indicates page/indicates that the page/ > + * range of unmapped size is returned in vfio_bitmap.data "A bitmap of the pages in the range of the unmapped size is returned in the user-provided 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) With the nits addressed, Reviewed-by: Cornelia Huck