From nobody Mon Apr 6 00:44:26 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 C4F10C46467 for ; Mon, 16 Jan 2023 04:06:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231863AbjAPEGl (ORCPT ); Sun, 15 Jan 2023 23:06:41 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49928 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231932AbjAPEGO (ORCPT ); Sun, 15 Jan 2023 23:06:14 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 357A683F4 for ; Sun, 15 Jan 2023 20:05:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1673841911; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ohcJPZKvAgOpbS44T4QtlSyb+QSlTiMgmt0MSyKR4Gk=; b=dByWWlzJUlJr4Ilzvfb/vn2zJBtGAdEkS1umPLChqlx/OIekOuVLwkK2ED6xblUFGE13Bq JUaUml7h/yxIRiWdGOJz7q7b7IF0M3aVHmBcSdUX5y7CTAb+APGDXSWN2k38eySkuquzYC tQ86uN2qlorQaaZQOjVLN6jO4Z46otY= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-404-oZ03pT2jOM-OSGkw5ehlOg-1; Sun, 15 Jan 2023 23:05:08 -0500 X-MC-Unique: oZ03pT2jOM-OSGkw5ehlOg-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 61A6F3828883; Mon, 16 Jan 2023 04:05:07 +0000 (UTC) Received: from gshan.redhat.com (vpn2-54-98.bne.redhat.com [10.64.54.98]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 4DDB0492B05; Mon, 16 Jan 2023 04:05:00 +0000 (UTC) From: Gavin Shan To: kvmarm@lists.linux.dev Cc: kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, pbonzini@redhat.com, maz@kernel.org, corbet@lwn.net, james.morse@arm.com, suzuki.poulose@arm.com, oliver.upton@linux.dev, yuzenghui@huawei.com, catalin.marinas@arm.com, will@kernel.org, ricarkol@google.com, eric.auger@redhat.com, yuzhe@nfschina.com, renzhengeek@gmail.com, ardb@kernel.org, peterx@redhat.com, seanjc@google.com, shan.gavin@gmail.com Subject: [PATCH 4/4] KVM: Improve warning report in mark_page_dirty_in_slot() Date: Mon, 16 Jan 2023 12:04:05 +0800 Message-Id: <20230116040405.260935-5-gshan@redhat.com> In-Reply-To: <20230116040405.260935-1-gshan@redhat.com> References: <20230116040405.260935-1-gshan@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.1 on 10.11.54.9 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" There are two warning reports about the dirty ring in the function. We have the wrong assumption that the dirty ring is always enabled when CONFIG_HAVE_KVM_DIRTY_RING is selected. This leads to warning messages about the dirty ring is reported even the dirty ring isn't enabled by the user space. Actually, the expected behaviour is to report the warning messages only when the dirty ring is enabled, instead of being configured. Fix it by enabling the checks and warning reports when the dirty ring has been enabled by the user space. Signed-off-by: Gavin Shan --- include/linux/kvm_dirty_ring.h | 5 +++++ virt/kvm/kvm_main.c | 25 ++++++++++++++----------- 2 files changed, 19 insertions(+), 11 deletions(-) diff --git a/include/linux/kvm_dirty_ring.h b/include/linux/kvm_dirty_ring.h index 4862c98d80d3..3fda0aa42858 100644 --- a/include/linux/kvm_dirty_ring.h +++ b/include/linux/kvm_dirty_ring.h @@ -42,6 +42,11 @@ static inline bool kvm_use_dirty_bitmap(struct kvm *kvm) return true; } =20 +static inline bool kvm_arch_allow_write_without_running_vcpu(struct kvm *k= vm) +{ + return false; +} + static inline int kvm_dirty_ring_alloc(struct kvm_dirty_ring *ring, int index, u32 size) { diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 90f538433916..a35c32bc84e1 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -3316,26 +3316,29 @@ void mark_page_dirty_in_slot(struct kvm *kvm, const struct kvm_memory_slot *memslot, gfn_t gfn) { - struct kvm_vcpu *vcpu =3D kvm_get_running_vcpu(); + struct kvm_vcpu *vcpu; unsigned long rel_gfn; u32 slot; =20 -#ifdef CONFIG_HAVE_KVM_DIRTY_RING - if (WARN_ON_ONCE(vcpu && vcpu->kvm !=3D kvm)) - return; - - WARN_ON_ONCE(!vcpu && !kvm_arch_allow_write_without_running_vcpu(kvm)); -#endif - if (!memslot || !kvm_slot_dirty_track_enabled(memslot)) return; =20 rel_gfn =3D gfn - memslot->base_gfn; slot =3D (memslot->as_id << 16) | memslot->id; =20 - if (kvm->dirty_ring_size && vcpu) - kvm_dirty_ring_push(vcpu, slot, rel_gfn); - else if (memslot->dirty_bitmap) + if (kvm->dirty_ring_size) { + vcpu =3D kvm_get_running_vcpu(); + if (vcpu) { + if (!WARN_ON_ONCE(vcpu->kvm !=3D kvm)) + kvm_dirty_ring_push(vcpu, slot, rel_gfn); + + return; + } + + WARN_ON_ONCE(!kvm_arch_allow_write_without_running_vcpu(kvm)); + } + + if (memslot->dirty_bitmap) set_bit_le(rel_gfn, memslot->dirty_bitmap); } EXPORT_SYMBOL_GPL(mark_page_dirty_in_slot); --=20 2.23.0