From patchwork Mon Jan 16 04:04:03 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gavin Shan X-Patchwork-Id: 13102602 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 7E7BAC54EBE for ; Mon, 16 Jan 2023 04:05:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231876AbjAPEFq (ORCPT ); Sun, 15 Jan 2023 23:05:46 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49962 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231689AbjAPEFh (ORCPT ); Sun, 15 Jan 2023 23:05:37 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5C7A583DC for ; Sun, 15 Jan 2023 20:04:59 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1673841898; 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=bA+wbP792KXwkm3/fGkTmvYSd+miHBdshWBI6pE7H5E=; b=bD0ez8qvAjjDAoE3ZQJtffTTrJu2zJm+q37v56usfR8Cqa8oJufpMWkg1gR4LEy2sPYl5D t8NPuk5sI3ky3sK9mTMVMGRE/bD3PBES4dDSCAiQKyAWsaB8PQ8QA41yRlsz+cPGdZ+gZt vsgQ1yIrYep9ZcYyw+uaEZXbT+wF/aw= 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-25-8MvBQx6yPoCdaaYFkjo74w-1; Sun, 15 Jan 2023 23:04:52 -0500 X-MC-Unique: 8MvBQx6yPoCdaaYFkjo74w-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 CBA301C08DA5; Mon, 16 Jan 2023 04:04:51 +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 D0EAD492B05; Mon, 16 Jan 2023 04:04:44 +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 2/4] KVM: arm64: Allow saving vgic3 pending tables in no running vcpu context Date: Mon, 16 Jan 2023 12:04:03 +0800 Message-Id: <20230116040405.260935-3-gshan@redhat.com> In-Reply-To: <20230116040405.260935-1-gshan@redhat.com> References: <20230116040405.260935-1-gshan@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.9 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org It's possible to save vgic3 pending tables in no running VCPU context. This is another unknown case detected by 'kvm-unit-tests'. # ./kvm-unit-tests/tests/its-pending-migration WARNING: CPU: 120 PID: 7973 at arch/arm64/kvm/../../../virt/kvm/kvm_main.c:3325 \ mark_page_dirty_in_slot+0x60/0xe0 : mark_page_dirty_in_slot+0x60/0xe0 __kvm_write_guest_page+0xcc/0x100 kvm_write_guest+0x7c/0xb0 vgic_v3_save_pending_tables+0x148/0x2a0 vgic_set_common_attr+0x158/0x240 vgic_v3_set_attr+0x4c/0x5c kvm_device_ioctl+0x100/0x160 __arm64_sys_ioctl+0xa8/0xf0 invoke_syscall.constprop.0+0x7c/0xd0 el0_svc_common.constprop.0+0x144/0x160 do_el0_svc+0x34/0x60 el0_svc+0x3c/0x1a0 el0t_64_sync_handler+0xb4/0x130 el0t_64_sync+0x178/0x17c Fix it by allowing to save VGIC3 pending tables in no running VCPU context. Reported-by: Zenghui Yu Signed-off-by: Gavin Shan --- Documentation/virt/kvm/api.rst | 3 +++ arch/arm64/kvm/vgic/vgic-v3.c | 2 ++ 2 files changed, 5 insertions(+) diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index 18b245a0ba02..7cf3d4b77703 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -8074,6 +8074,9 @@ NOTE: One example of using the backup bitmap is saving arm64 vgic/its tables and vgic3 LPI pending status through KVM_DEV_ARM_{VGIC_GRP_CTRL, ITS_SAVE_TABLES} and KVM_DEV_ARM_{VGIC_GRP_CTRL, ITS_RESTORE_TABLES} command on KVM device "kvm-arm-vgic-its" when dirty ring is enabled. +The backup bitmap is also used when vgic3 pending table is saved +through KVM_DEV_ARM_{VGIC_GRP_CTRL, VGIC_SAVE_PENDING_TABLES} command +on KVM device "kvm-arm-vgic-v3". 8.30 KVM_CAP_XEN_HVM -------------------- diff --git a/arch/arm64/kvm/vgic/vgic-v3.c b/arch/arm64/kvm/vgic/vgic-v3.c index 32998c8587a8..1e6b5f19d524 100644 --- a/arch/arm64/kvm/vgic/vgic-v3.c +++ b/arch/arm64/kvm/vgic/vgic-v3.c @@ -440,7 +440,9 @@ int vgic_v3_save_pending_tables(struct kvm *kvm) else val &= ~(1 << bit_nr); + dist->save_vgic_v3_tables_in_progress = true; ret = kvm_write_guest_lock(kvm, ptr, &val, 1); + dist->save_vgic_v3_tables_in_progress = false; if (ret) goto out; }