From patchwork Tue May 5 21:54:44 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alex Williamson X-Patchwork-Id: 11529999 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 393621668 for ; Tue, 5 May 2020 21:54:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 21B7C20752 for ; Tue, 5 May 2020 21:54:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="RDVi3KLo" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729270AbgEEVyx (ORCPT ); Tue, 5 May 2020 17:54:53 -0400 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:59818 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727785AbgEEVyw (ORCPT ); Tue, 5 May 2020 17:54:52 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1588715691; 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=Eckl6hH0AbgL49kEhmxA8Bwx9T7n/rxh8xbcvWxSc1I=; b=RDVi3KLoJDB3txgzful5l9K85EzNXSk8ZqHzCD5oV3Q4kJyi6ZJV1BmAVIx7rAO2hvY5Rt qtytD7h2/qfIzGtlssmkZMZE1BaC62CQk+Q3qC99O8gy5hx3p61KqstIh4VSbh34YUMVMY cX7Zk38HCvA5AOpaWQ9WkI3O5px+01Q= 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-295-VOYbBK-OMSGNzfOZspF_2Q-1; Tue, 05 May 2020 17:54:49 -0400 X-MC-Unique: VOYbBK-OMSGNzfOZspF_2Q-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id ADDE2107ACCA; Tue, 5 May 2020 21:54:48 +0000 (UTC) Received: from gimli.home (ovpn-113-95.phx2.redhat.com [10.3.113.95]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3C52770538; Tue, 5 May 2020 21:54:45 +0000 (UTC) Subject: [PATCH v2 1/3] vfio/type1: Support faulting PFNMAP vmas From: Alex Williamson To: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org, cohuck@redhat.com, jgg@ziepe.ca Date: Tue, 05 May 2020 15:54:44 -0600 Message-ID: <158871568480.15589.17339878308143043906.stgit@gimli.home> In-Reply-To: <158871401328.15589.17598154478222071285.stgit@gimli.home> References: <158871401328.15589.17598154478222071285.stgit@gimli.home> User-Agent: StGit/0.19-dirty MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org With conversion to follow_pfn(), DMA mapping a PFNMAP range depends on the range being faulted into the vma. Add support to manually provide that, in the same way as done on KVM with hva_to_pfn_remapped(). Signed-off-by: Alex Williamson Reviewed-by: Peter Xu --- drivers/vfio/vfio_iommu_type1.c | 36 +++++++++++++++++++++++++++++++++--- 1 file changed, 33 insertions(+), 3 deletions(-) diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index cc1d64765ce7..4a4cb7cd86b2 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -317,6 +317,32 @@ static int put_pfn(unsigned long pfn, int prot) return 0; } +static int follow_fault_pfn(struct vm_area_struct *vma, struct mm_struct *mm, + unsigned long vaddr, unsigned long *pfn, + bool write_fault) +{ + int ret; + + ret = follow_pfn(vma, vaddr, pfn); + if (ret) { + bool unlocked = false; + + ret = fixup_user_fault(NULL, mm, vaddr, + FAULT_FLAG_REMOTE | + (write_fault ? FAULT_FLAG_WRITE : 0), + &unlocked); + if (unlocked) + return -EAGAIN; + + if (ret) + return ret; + + ret = follow_pfn(vma, vaddr, pfn); + } + + return ret; +} + static int vaddr_get_pfn(struct mm_struct *mm, unsigned long vaddr, int prot, unsigned long *pfn) { @@ -339,12 +365,16 @@ static int vaddr_get_pfn(struct mm_struct *mm, unsigned long vaddr, vaddr = untagged_addr(vaddr); +retry: vma = find_vma_intersection(mm, vaddr, vaddr + 1); if (vma && vma->vm_flags & VM_PFNMAP) { - if (!follow_pfn(vma, vaddr, pfn) && - is_invalid_reserved_pfn(*pfn)) - ret = 0; + ret = follow_fault_pfn(vma, mm, vaddr, pfn, prot & IOMMU_WRITE); + if (ret == -EAGAIN) + goto retry; + + if (!ret && !is_invalid_reserved_pfn(*pfn)) + ret = -EFAULT; } done: up_read(&mm->mmap_sem);