From patchwork Tue Sep 20 14:40:24 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vitaly Kuznetsov X-Patchwork-Id: 12982493 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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 62F9CC6FA82 for ; Tue, 20 Sep 2022 18:23:15 +0000 (UTC) Received: from localhost ([::1]:57932 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oahtq-0002jt-40 for qemu-devel@archiver.kernel.org; Tue, 20 Sep 2022 14:23:14 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:47476) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oaeQQ-0008Uk-IV for qemu-devel@nongnu.org; Tue, 20 Sep 2022 10:40:38 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:50622) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oaeQN-0008Q8-7q for qemu-devel@nongnu.org; Tue, 20 Sep 2022 10:40:37 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1663684833; 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; bh=WRKE9GwciU3Lm1vK7T0mJUi+DG1hCjul8hYQkKsmN+Q=; b=ANUD1GfTFOIB28Gl0kh/SEbSGTZCVRi1UZDOp/iPgvJY/Fc3w5tqFakzZbqbEzpR6NyaPx uX+Sq1jh46DO3OmsFY04I6JDwDE/o35M2VGcEAGfiPJV/Icx7DNWTRw1fO38AAw8aCGvRR uDV2vTREKwQBlTjizwrvV7LqpUyJ128= 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-483-YcWVuJSFMuCrWmHHe5O4KQ-1; Tue, 20 Sep 2022 10:40:32 -0400 X-MC-Unique: YcWVuJSFMuCrWmHHe5O4KQ-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id D8C5C29AA2E9; Tue, 20 Sep 2022 14:40:31 +0000 (UTC) Received: from fedora.redhat.com (unknown [10.40.194.159]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9FD1C1759F; Tue, 20 Sep 2022 14:40:30 +0000 (UTC) From: Vitaly Kuznetsov To: qemu-devel@nongnu.org, Paolo Bonzini Cc: Marcelo Tosatti , Oliver Upton , Maxim Levitsky Subject: [PATCH] i386: Fix KVM_CAP_ADJUST_CLOCK capability check Date: Tue, 20 Sep 2022 16:40:24 +0200 Message-Id: <20220920144024.3559708-1-vkuznets@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.5 Received-SPF: pass client-ip=170.10.129.124; envelope-from=vkuznets@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" KVM commit c68dc1b577ea ("KVM: x86: Report host tsc and realtime values in KVM_GET_CLOCK") broke migration of certain workloads, e.g. Win11 + WSL2 guest reboots immediately after migration. KVM, however, is not to blame this time. When KVM_CAP_ADJUST_CLOCK capability is checked, the result is all supported flags (which the above mentioned KVM commit enhanced) but kvm_has_adjust_clock_stable() wants it to be KVM_CLOCK_TSC_STABLE precisely. The result is that 'clock_is_reliable' is not set in vmstate and the saved clock reading is discarded in kvmclock_vm_state_change(). Signed-off-by: Vitaly Kuznetsov --- target/i386/kvm/kvm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c index a1fd1f53791d..c33192a87dcb 100644 --- a/target/i386/kvm/kvm.c +++ b/target/i386/kvm/kvm.c @@ -157,7 +157,7 @@ bool kvm_has_adjust_clock_stable(void) { int ret = kvm_check_extension(kvm_state, KVM_CAP_ADJUST_CLOCK); - return (ret == KVM_CLOCK_TSC_STABLE); + return ret & KVM_CLOCK_TSC_STABLE; } bool kvm_has_adjust_clock(void)