From patchwork Sat Jun 2 16:26:49 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Alex Williamson X-Patchwork-Id: 10444925 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 811426028E for ; Sat, 2 Jun 2018 16:27:28 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7245A28AA4 for ; Sat, 2 Jun 2018 16:27:28 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6659228AA8; Sat, 2 Jun 2018 16:27:28 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id DC41128AA5 for ; Sat, 2 Jun 2018 16:27:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751812AbeFBQ04 (ORCPT ); Sat, 2 Jun 2018 12:26:56 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:51320 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751624AbeFBQ0z (ORCPT ); Sat, 2 Jun 2018 12:26:55 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 97784401EF04; Sat, 2 Jun 2018 16:26:54 +0000 (UTC) Received: from w520.home (ovpn-116-135.phx2.redhat.com [10.3.116.135]) by smtp.corp.redhat.com (Postfix) with ESMTP id BEA371006EB5; Sat, 2 Jun 2018 16:26:50 +0000 (UTC) Subject: [PATCH] Revert "vfio/type1: Improve memory pinning process for raw PFN mapping" From: Alex Williamson To: alex.williamson@redhat.com Cc: "Jason Cai \(Xiang Feng\)" , Amadeusz =?utf-8?b?U8WCYXdpxYRza2k=?= , kvm@vger.kernel.org, linux-kernel@vger.kernel.org Date: Sat, 02 Jun 2018 10:26:49 -0600 Message-ID: <152795678646.18023.2344946004912261972.stgit@w520.home> User-Agent: StGit/0.18-136-gffd7 MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.78 on 10.11.54.3 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.5]); Sat, 02 Jun 2018 16:26:54 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.5]); Sat, 02 Jun 2018 16:26:54 +0000 (UTC) for IP:'10.11.54.3' DOMAIN:'int-mx03.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'alex.williamson@redhat.com' RCPT:'' Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Bisection by Amadeusz Sławiński implicates this commit leading to bad page state issues after VM shutdown, likely due to unbalanced page references. The original commit was intended only as a performance improvement, therefore revert for offline rework. Link: https://lkml.org/lkml/2018/6/2/97 Fixes: 356e88ebe447 ("vfio/type1: Improve memory pinning process for raw PFN mapping") Cc: Jason Cai (Xiang Feng) Reported-by: Amadeusz Sławiński Signed-off-by: Alex Williamson --- drivers/vfio/vfio_iommu_type1.c | 25 ++++++++++--------------- 1 file changed, 10 insertions(+), 15 deletions(-) diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index 5c212bf29640..3c082451ab1a 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -404,6 +404,7 @@ static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr, { unsigned long pfn = 0; long ret, pinned = 0, lock_acct = 0; + bool rsvd; dma_addr_t iova = vaddr - dma->vaddr + dma->iova; /* This code path is only user initiated */ @@ -414,23 +415,14 @@ static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr, if (ret) return ret; - if (is_invalid_reserved_pfn(*pfn_base)) { - struct vm_area_struct *vma; - - down_read(¤t->mm->mmap_sem); - vma = find_vma_intersection(current->mm, vaddr, vaddr + 1); - pinned = min_t(long, npage, vma_pages(vma)); - up_read(¤t->mm->mmap_sem); - return pinned; - } - pinned++; + rsvd = is_invalid_reserved_pfn(*pfn_base); /* * Reserved pages aren't counted against the user, externally pinned * pages are already counted against the user. */ - if (!vfio_find_vpfn(dma, iova)) { + if (!rsvd && !vfio_find_vpfn(dma, iova)) { if (!lock_cap && current->mm->locked_vm + 1 > limit) { put_pfn(*pfn_base, dma->prot); pr_warn("%s: RLIMIT_MEMLOCK (%ld) exceeded\n", __func__, @@ -450,12 +442,13 @@ static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr, if (ret) break; - if (pfn != *pfn_base + pinned) { + if (pfn != *pfn_base + pinned || + rsvd != is_invalid_reserved_pfn(pfn)) { put_pfn(pfn, dma->prot); break; } - if (!vfio_find_vpfn(dma, iova)) { + if (!rsvd && !vfio_find_vpfn(dma, iova)) { if (!lock_cap && current->mm->locked_vm + lock_acct + 1 > limit) { put_pfn(pfn, dma->prot); @@ -473,8 +466,10 @@ static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr, unpin_out: if (ret) { - for (pfn = *pfn_base ; pinned ; pfn++, pinned--) - put_pfn(pfn, dma->prot); + if (!rsvd) { + for (pfn = *pfn_base ; pinned ; pfn++, pinned--) + put_pfn(pfn, dma->prot); + } return ret; }