From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ot1-f71.google.com (mail-ot1-f71.google.com [209.85.210.71]) by kanga.kvack.org (Postfix) with ESMTP id 9C28A8E0001 for ; Tue, 18 Sep 2018 07:59:00 -0400 (EDT) Received: by mail-ot1-f71.google.com with SMTP id h39-v6so772491otd.17 for ; Tue, 18 Sep 2018 04:59:00 -0700 (PDT) Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com. [148.163.158.5]) by mx.google.com with ESMTPS id a65-v6si6187045otc.361.2018.09.18.04.58.59 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 18 Sep 2018 04:58:59 -0700 (PDT) Received: from pps.filterd (m0098413.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w8IBsMr2099418 for ; Tue, 18 Sep 2018 07:58:58 -0400 Received: from e15.ny.us.ibm.com (e15.ny.us.ibm.com [129.33.205.205]) by mx0b-001b2d01.pphosted.com with ESMTP id 2mk0w205bk-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 18 Sep 2018 07:58:58 -0400 Received: from localhost by e15.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 18 Sep 2018 07:58:57 -0400 From: "Aneesh Kumar K.V" Subject: [PATCH V3 0/2] mm/kvm/vfio/ppc64: Migrate compound pages out of CMA region Date: Tue, 18 Sep 2018 17:28:37 +0530 Message-Id: <20180918115839.22154-1-aneesh.kumar@linux.ibm.com> Sender: owner-linux-mm@kvack.org List-ID: To: akpm@linux-foundation.org, Michal Hocko , Alexey Kardashevskiy , mpe@ellerman.id.au Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, "Aneesh Kumar K.V" ppc64 use CMA area for the allocation of guest page table (hash page table). We won't be able to start guest if we fail to allocate hash page table. We have observed hash table allocation failure because we failed to migrate pages out of CMA region because they were pinned. This happen when we are using VFIO. VFIO on ppc64 pins the entire guest RAM. If the guest RAM pages get allocated out of CMA region, we won't be able to migrate those pages. The pages are also pinned for the lifetime of the guest. Currently we support migration of non-compound pages. With THP and with the addition of hugetlb migration we can end up allocating compound pages from CMA region. This patch series add support for migrating compound pages. The first path adds the helper get_user_pages_cma_migrate() which pin the page making sure we migrate them out of CMA region before incrementing the reference count. Aneesh Kumar K.V (2): mm: Add get_user_pages_cma_migrate powerpc/mm/iommu: Allow migration of cma allocated pages during mm_iommu_get arch/powerpc/mm/mmu_context_iommu.c | 120 ++++++++----------------- include/linux/hugetlb.h | 2 + include/linux/migrate.h | 3 + mm/hugetlb.c | 4 +- mm/migrate.c | 132 ++++++++++++++++++++++++++++ 5 files changed, 174 insertions(+), 87 deletions(-) -- 2.17.1