From patchwork Tue Sep 8 15:25:56 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 309981 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=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 18C16C43461 for ; Tue, 8 Sep 2020 18:36:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CDD6B2080A for ; Tue, 8 Sep 2020 18:36:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599590199; bh=cNMG3aGwW2iOudGRfRSdU1ldC+QY0NSEFEw8CW4f2ME=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=2IIfd/yazPi2/EkPRgsTxCvK4yhcyqftIvtd4vVeJ1sJ4kK4vvAbxpspZf7VtSExU OKjwU72H1dioc00PxdFZoWzP0O0HSILuv5TIpNOsKgNQpQ4emlGTlFMCHCwOfKathk KSNoQ5S9V306nEQuyqqi/slTiAqI82FF7BgdkeAU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731721AbgIHSgG (ORCPT ); Tue, 8 Sep 2020 14:36:06 -0400 Received: from mail.kernel.org ([198.145.29.99]:56086 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731357AbgIHQJV (ORCPT ); Tue, 8 Sep 2020 12:09:21 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id EEA5624178; Tue, 8 Sep 2020 15:49:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599580162; bh=cNMG3aGwW2iOudGRfRSdU1ldC+QY0NSEFEw8CW4f2ME=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=J0G1Ff9OYUlUkt6Gc8fv6pPW8WxJhRFRAKay8heMSqt/J9+vPLEUbwfjvCgn9HGjZ lWv9GllU/+kkrG3ub3WqqsYrm2lQAftb01NpMGt2BKUVvPTCjJszH03Qyc+mFMxCEy qQWV9WxQgwt/2c+qMyMLZYxEI5ezBy1jhII5Iad0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Peter Xu , Alex Williamson , Ajay Kaher , Sasha Levin Subject: [PATCH 4.19 55/88] vfio/type1: Support faulting PFNMAP vmas Date: Tue, 8 Sep 2020 17:25:56 +0200 Message-Id: <20200908152223.885686657@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200908152221.082184905@linuxfoundation.org> References: <20200908152221.082184905@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Alex Williamson commit 41311242221e3482b20bfed10fa4d9db98d87016 upstream. 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(). Reviewed-by: Peter Xu Signed-off-by: Alex Williamson [Ajay: Regenerated the patch for v4.19] Signed-off-by: Ajay Kaher Signed-off-by: Sasha Levin --- 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 52083b710b87e..05d8553635ee7 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -343,6 +343,32 @@ 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) { @@ -382,12 +408,16 @@ static int vaddr_get_pfn(struct mm_struct *mm, unsigned long vaddr, down_read(&mm->mmap_sem); +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; } up_read(&mm->mmap_sem);