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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT 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 033C6C43441 for ; Fri, 9 Nov 2018 11:07:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C897920827 for ; Fri, 9 Nov 2018 11:07:39 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C897920827 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=8bytes.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728496AbeKIUro (ORCPT ); Fri, 9 Nov 2018 15:47:44 -0500 Received: from 8bytes.org ([81.169.241.247]:48988 "EHLO theia.8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728343AbeKIUr2 (ORCPT ); Fri, 9 Nov 2018 15:47:28 -0500 Received: by theia.8bytes.org (Postfix, from userid 1000) id 1F032533; Fri, 9 Nov 2018 12:07:20 +0100 (CET) From: Joerg Roedel To: Alex Williamson , Joerg Roedel Cc: iommu@lists.linux-foundation.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, jroedel@suse.de Subject: [PATCH 6/7] iommu/amd: Allow to upgrade page-size Date: Fri, 9 Nov 2018 12:07:11 +0100 Message-Id: <20181109110712.12469-7-joro@8bytes.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181109110712.12469-1-joro@8bytes.org> References: <20181109110712.12469-1-joro@8bytes.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Joerg Roedel Before this patch the iommu_map_page() function failed when it tried to map a huge-page where smaller mappings existed before. With this change the page-table pages of the old mappings are teared down, so that the huge-page can be mapped. Signed-off-by: Joerg Roedel --- drivers/iommu/amd_iommu.c | 29 +++++++++++++++++++++++++++-- 1 file changed, 27 insertions(+), 2 deletions(-) diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c index c539b2a59019..71797b3d67e5 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -1557,6 +1557,25 @@ static u64 *fetch_pte(struct protection_domain *domain, return pte; } +static struct page *free_clear_pte(u64 *pte, u64 pteval, struct page *freelist) +{ + unsigned long pt; + int mode; + + while (cmpxchg64(pte, pteval, 0) != pteval) { + pr_warn("AMD-Vi: IOMMU pte changed since we read it\n"); + pteval = *pte; + } + + if (!IOMMU_PTE_PRESENT(pteval)) + return freelist; + + pt = (unsigned long)IOMMU_PTE_PAGE(pteval); + mode = IOMMU_PTE_MODE(pteval); + + return free_sub_pt(pt, mode, freelist); +} + /* * Generic mapping functions. It maps a physical address into a DMA * address space. It allocates the page table pages if necessary. @@ -1571,6 +1590,7 @@ static int iommu_map_page(struct protection_domain *dom, int prot, gfp_t gfp) { + struct page *freelist = NULL; u64 __pte, *pte; int i, count; @@ -1587,8 +1607,10 @@ static int iommu_map_page(struct protection_domain *dom, return -ENOMEM; for (i = 0; i < count; ++i) - if (IOMMU_PTE_PRESENT(pte[i])) - return -EBUSY; + freelist = free_clear_pte(&pte[i], pte[i], freelist); + + if (freelist != NULL) + dom->updated = true; if (count > 1) { __pte = PAGE_SIZE_PTE(__sme_set(phys_addr), page_size); @@ -1606,6 +1628,9 @@ static int iommu_map_page(struct protection_domain *dom, update_domain(dom); + /* Everything flushed out, free pages now */ + free_page_list(freelist); + return 0; } -- 2.17.1