From nobody Mon Feb 9 23:43:11 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E531FC77B7C for ; Sat, 13 May 2023 00:38:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241506AbjEMAiu (ORCPT ); Fri, 12 May 2023 20:38:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45032 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241802AbjEMAiF (ORCPT ); Fri, 12 May 2023 20:38:05 -0400 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0D34B5FCD for ; Fri, 12 May 2023 17:37:11 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id 3f1490d57ef6-ba2d0b391d3so15107503276.2 for ; Fri, 12 May 2023 17:37:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1683938211; x=1686530211; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:from:to:cc:subject:date:message-id:reply-to; bh=d+sFY9wdlYEr+BsMeb/f8vTRCaTs7vfifkJ4zvl7LGw=; b=64N8psPjCU8NCbfgAoPhVHhIo35afPxNCSfUEDPc6JEFhfmjZIqhvtqtCxju3ayooD rLtO6OgYd01HPHrZnVMraPg/wvIulWsNrZaYYd3Q2cuVPa4BEcmEV3mEsul3XrhRjsp+ aJ3JMXVJz3CR+BKQBzSr5PUTPuq5LMv/qpzFT9AXutEQGIhFf59wMsyaAHBpLpysfc/Q 5h8AgBMeBJE20odwJFjCXSKGq2qIWtRbb+o7daVN32UhhZQwjWvMckTBuPmrfJMgaGYa tWHBeWXd1xseZCzWjFZKA19DhbXGNxq1i3PG7V0P1+RQ2Cbwc2JaOc8fDwY7PDd1c0r8 ZJKg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1683938211; x=1686530211; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=d+sFY9wdlYEr+BsMeb/f8vTRCaTs7vfifkJ4zvl7LGw=; b=DyFobEwTk4saSxXY/YMxcjJxzEQDWKwzdUZSz7kNUL5QInrIJBBZEm14gQc7C1ZbkH RyTgwKhdC5u8IXNZ26Nv/xnmtC0YQT4fafpYeWdlhWhnFHeC11PK3sy6t2q0sJf0emgq TwFfz+XqGp6+t6IpkDdEwLWohD4oo8K2Zu5d1XXnKmKhOOY7biQgg7h2staVzyDaunuN HQe95QvRsijfvMR5pQqrrRtOo8vLmrFf3wjzdjR4xy+uOMdZsc2p1mkRWrih/9JKrxEa i2JqbltRUG0IXt76JkKOeuiBPUtkYLxl3TWZ4nQBONiSUWMjIqFNc/LgESqJc9RVBio1 cIJA== X-Gm-Message-State: AC+VfDzQlAqmPuzQgX9U0pO6ltOIQ4W8BGMw3IpDatTjkdpvc3U2CwJ+ k0H5Fo16YMAQ2BRjk5WrBSCBu/LxFu4= X-Google-Smtp-Source: ACHHUZ5zdcnj/hq68r0lrjsegbj6c4YZMheMUdNtJ3k1/upYeQmR6HdFpgZIKNg6Oz6JUMAbVtXPBMF+WH4= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a25:1241:0:b0:ba6:3890:3e55 with SMTP id 62-20020a251241000000b00ba638903e55mr6939739ybs.2.1683938211420; Fri, 12 May 2023 17:36:51 -0700 (PDT) Reply-To: Sean Christopherson Date: Fri, 12 May 2023 17:35:56 -0700 In-Reply-To: <20230513003600.818142-1-seanjc@google.com> Mime-Version: 1.0 References: <20230513003600.818142-1-seanjc@google.com> X-Mailer: git-send-email 2.40.1.606.ga4b1b128d6-goog Message-ID: <20230513003600.818142-25-seanjc@google.com> Subject: [PATCH v3 24/28] KVM: x86/mmu: Assert that correct locks are held for page write-tracking From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini , Zhenyu Wang , Zhi Wang Cc: kvm@vger.kernel.org, intel-gvt-dev@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org, Yan Zhao , Ben Gardon Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" When adding/removing gfns to/from write-tracking, assert that mmu_lock is held for write, and that either slots_lock or kvm->srcu is held. mmu_lock must be held for write to protect gfn_write_track's refcount, and SRCU or slots_lock must be held to protect the memslot itself. Tested-by: Yan Zhao Signed-off-by: Sean Christopherson --- arch/x86/kvm/mmu/page_track.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/arch/x86/kvm/mmu/page_track.c b/arch/x86/kvm/mmu/page_track.c index b835ba7f325c..29ae61f1e303 100644 --- a/arch/x86/kvm/mmu/page_track.c +++ b/arch/x86/kvm/mmu/page_track.c @@ -12,6 +12,7 @@ */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt =20 +#include #include #include =20 @@ -77,9 +78,6 @@ static void update_gfn_write_track(struct kvm_memory_slot= *slot, gfn_t gfn, * add guest page to the tracking pool so that corresponding access on that * page will be intercepted. * - * It should be called under the protection both of mmu-lock and kvm->srcu - * or kvm->slots_lock. - * * @kvm: the guest instance we are interested in. * @slot: the @gfn belongs to. * @gfn: the guest page. @@ -87,6 +85,11 @@ static void update_gfn_write_track(struct kvm_memory_slo= t *slot, gfn_t gfn, void kvm_write_track_add_gfn(struct kvm *kvm, struct kvm_memory_slot *slot, gfn_t gfn) { + lockdep_assert_held_write(&kvm->mmu_lock); + + lockdep_assert_once(lockdep_is_held(&kvm->slots_lock) || + srcu_read_lock_held(&kvm->srcu)); + if (WARN_ON(!kvm_page_track_write_tracking_enabled(kvm))) return; =20 @@ -107,9 +110,6 @@ EXPORT_SYMBOL_GPL(kvm_write_track_add_gfn); * remove the guest page from the tracking pool which stops the intercepti= on * of corresponding access on that page. * - * It should be called under the protection both of mmu-lock and kvm->srcu - * or kvm->slots_lock. - * * @kvm: the guest instance we are interested in. * @slot: the @gfn belongs to. * @gfn: the guest page. @@ -117,6 +117,11 @@ EXPORT_SYMBOL_GPL(kvm_write_track_add_gfn); void kvm_write_track_remove_gfn(struct kvm *kvm, struct kvm_memory_slot *slot, gfn_t gfn) { + lockdep_assert_held_write(&kvm->mmu_lock); + + lockdep_assert_once(lockdep_is_held(&kvm->slots_lock) || + srcu_read_lock_held(&kvm->srcu)); + if (WARN_ON(!kvm_page_track_write_tracking_enabled(kvm))) return; =20 --=20 2.40.1.606.ga4b1b128d6-goog