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=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL 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 896B1C432C3 for ; Mon, 15 Mar 2021 14:53:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4A0D364E4D for ; Mon, 15 Mar 2021 14:53:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240613AbhCOOwa (ORCPT ); Mon, 15 Mar 2021 10:52:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52552 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237232AbhCOOgt (ORCPT ); Mon, 15 Mar 2021 10:36:49 -0400 Received: from mail-wm1-x34a.google.com (mail-wm1-x34a.google.com [IPv6:2a00:1450:4864:20::34a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3CC0FC0613E9 for ; Mon, 15 Mar 2021 07:36:39 -0700 (PDT) Received: by mail-wm1-x34a.google.com with SMTP id a65so2913248wmh.1 for ; Mon, 15 Mar 2021 07:36:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=J1uZIE4CatR8RJ2mwUZGBIvYuAMTy17ux6AGbOX5tFk=; b=quH1WWPr+L1SVwBqv31K38Go2mHpdC6nZ0w0GUgWu8lifd6IDz7tnxeCHBvwfxXcid s/cfv6PNBlw7Tv1DYVDfMOsXnBOEXJFlXhMZyBMoZVhKnghB6bZBQ7RXezVsiD4bljVh lJBqoO4Or/KxawhVR2OPnIGrxhVyjXNvg07Fc+ZEFDUsWiUlW9oHKY+QEXLr9k42aYSH d2Cae4A8DBkXpZvxeLTGbGBr2odV4gqnrZpx31EngUzons5PvcQ6ycsc99xvdaHgxaKm V/XOC0HOZ3lOrer8gP70svjqgVCAXPSm6Ym7SYFjCDsB/ZmUMa2sDLVxAtskeXAdYfBu oHQw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=J1uZIE4CatR8RJ2mwUZGBIvYuAMTy17ux6AGbOX5tFk=; b=XTZlJgDDC4H5jpxUgTvJsASWUZVTadAQB6WhFh21VwUQJVTaFztxKBlYZWBLssWtHp rp1M3YWnQnl/PsilKNoJ37oUhY6wDP3Z/oZxk9FRXqGZvaqKTHv6n9PHe/2VjWuky5Sk nyndgzGOWQZRLUJYtNoJxqLdxfB4w1+pBMlzonxm3N7s8zJc9+8ZxiiqG6eX1sUDV8x9 RqwKkxh61Qjjk9yyMFCDABwGI987Q0QfkFQ11EU4UPq79UDRnozgRcQUnF4dWgtmCjar B9WV9w+/pUk+NJ/K9WJ8iHHgkLgjm3rt4rhw2ZqspsCwmvy4D3y+fcFpRSv4VyCS7Csw eHAw== X-Gm-Message-State: AOAM533Ir5QrQb/6Te1qG7o6ZPE0GrjOLbESaBT6pVSLU//mbXtxFCsx MObsxirqbPqtud7jWZ4SSJOIRT8h9tiM X-Google-Smtp-Source: ABdhPJxe4+QHHGpZyqH28YWZv8YfJrDVsBARhsCBGZiD6vsppmOxHGv9C0FMe9dp3bfpi8X+Fs4PaGFGP24s X-Received: from r2d2-qp.c.googlers.com ([fda3:e722:ac3:10:28:9cb1:c0a8:1652]) (user=qperret job=sendgmr) by 2002:a05:600c:2053:: with SMTP id p19mr26380067wmg.87.1615818997861; Mon, 15 Mar 2021 07:36:37 -0700 (PDT) Date: Mon, 15 Mar 2021 14:35:28 +0000 In-Reply-To: <20210315143536.214621-1-qperret@google.com> Message-Id: <20210315143536.214621-29-qperret@google.com> Mime-Version: 1.0 References: <20210315143536.214621-1-qperret@google.com> X-Mailer: git-send-email 2.31.0.rc2.261.g7f71774620-goog Subject: [PATCH v5 28/36] KVM: arm64: Always zero invalid PTEs From: Quentin Perret To: catalin.marinas@arm.com, will@kernel.org, maz@kernel.org, james.morse@arm.com, julien.thierry.kdev@gmail.com, suzuki.poulose@arm.com Cc: android-kvm@google.com, seanjc@google.com, mate.toth-pal@arm.com, linux-kernel@vger.kernel.org, robh+dt@kernel.org, linux-arm-kernel@lists.infradead.org, kernel-team@android.com, kvmarm@lists.cs.columbia.edu, tabba@google.com, ardb@kernel.org, mark.rutland@arm.com, dbrazdil@google.com, qperret@google.com Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org kvm_set_invalid_pte() currently only clears bit 0 from a PTE because stage2_map_walk_table_post() needs to be able to follow the anchor. In preparation for re-using bits 63-01 from invalid PTEs, make sure to zero it entirely by ensuring to cache the anchor's child upfront. Acked-by: Will Deacon Suggested-by: Will Deacon Signed-off-by: Quentin Perret --- arch/arm64/kvm/hyp/pgtable.c | 26 ++++++++++++++++---------- 1 file changed, 16 insertions(+), 10 deletions(-) diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c index bdd6e3d4eeb6..f37b4179b880 100644 --- a/arch/arm64/kvm/hyp/pgtable.c +++ b/arch/arm64/kvm/hyp/pgtable.c @@ -156,10 +156,9 @@ static kvm_pte_t *kvm_pte_follow(kvm_pte_t pte, struct kvm_pgtable_mm_ops *mm_op return mm_ops->phys_to_virt(kvm_pte_to_phys(pte)); } -static void kvm_set_invalid_pte(kvm_pte_t *ptep) +static void kvm_clear_pte(kvm_pte_t *ptep) { - kvm_pte_t pte = *ptep; - WRITE_ONCE(*ptep, pte & ~KVM_PTE_VALID); + WRITE_ONCE(*ptep, 0); } static void kvm_set_table_pte(kvm_pte_t *ptep, kvm_pte_t *childp, @@ -443,6 +442,7 @@ struct stage2_map_data { kvm_pte_t attr; kvm_pte_t *anchor; + kvm_pte_t *childp; struct kvm_s2_mmu *mmu; void *memcache; @@ -532,7 +532,7 @@ static int stage2_map_walker_try_leaf(u64 addr, u64 end, u32 level, * There's an existing different valid leaf entry, so perform * break-before-make. */ - kvm_set_invalid_pte(ptep); + kvm_clear_pte(ptep); kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, data->mmu, addr, level); mm_ops->put_page(ptep); } @@ -553,7 +553,8 @@ static int stage2_map_walk_table_pre(u64 addr, u64 end, u32 level, if (!kvm_block_mapping_supported(addr, end, data->phys, level)) return 0; - kvm_set_invalid_pte(ptep); + data->childp = kvm_pte_follow(*ptep, data->mm_ops); + kvm_clear_pte(ptep); /* * Invalidate the whole stage-2, as we may have numerous leaf @@ -599,7 +600,7 @@ static int stage2_map_walk_leaf(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, * will be mapped lazily. */ if (kvm_pte_valid(pte)) { - kvm_set_invalid_pte(ptep); + kvm_clear_pte(ptep); kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, data->mmu, addr, level); mm_ops->put_page(ptep); } @@ -615,19 +616,24 @@ static int stage2_map_walk_table_post(u64 addr, u64 end, u32 level, struct stage2_map_data *data) { struct kvm_pgtable_mm_ops *mm_ops = data->mm_ops; + kvm_pte_t *childp; int ret = 0; if (!data->anchor) return 0; - mm_ops->put_page(kvm_pte_follow(*ptep, mm_ops)); - mm_ops->put_page(ptep); - if (data->anchor == ptep) { + childp = data->childp; data->anchor = NULL; + data->childp = NULL; ret = stage2_map_walk_leaf(addr, end, level, ptep, data); + } else { + childp = kvm_pte_follow(*ptep, mm_ops); } + mm_ops->put_page(childp); + mm_ops->put_page(ptep); + return ret; } @@ -736,7 +742,7 @@ static int stage2_unmap_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, * block entry and rely on the remaining portions being faulted * back lazily. */ - kvm_set_invalid_pte(ptep); + kvm_clear_pte(ptep); kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, mmu, addr, level); mm_ops->put_page(ptep); -- 2.31.0.rc2.261.g7f71774620-goog