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 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 CB011C54EE9 for ; Tue, 20 Sep 2022 22:53:27 +0000 (UTC) Received: from localhost ([::1]:40004 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oam7K-0007Ox-Fs for qemu-devel@archiver.kernel.org; Tue, 20 Sep 2022 18:53:26 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:51396) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oaibP-0003V4-GF for qemu-devel@nongnu.org; Tue, 20 Sep 2022 15:08:15 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:46752) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oaibE-00035T-Sj for qemu-devel@nongnu.org; Tue, 20 Sep 2022 15:08:13 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1663700881; 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: in-reply-to:in-reply-to:references:references; bh=ktzlZpwOw1mqf4yROmBwwB/LWKCZseMzSDKapspkc5s=; b=J2DvfgPkPas2DouAsaYVHMQFCO0bd11rFObcg7zsZo+5rEzIaTIm6lf3N54fOGnsAkuGMG VDawbEMabtlgiGPR8MKGVFi5kh5D73EEwvQ+Orxn9tEcoIGVfB3+PGIPCfV61dMfuGaHag zp4UDwf89lq6PoUY9TIQUO+nP10q5/s= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-201-Urp3PljJP8uEskjZfpjyBg-1; Tue, 20 Sep 2022 15:06:22 -0400 X-MC-Unique: Urp3PljJP8uEskjZfpjyBg-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 CF1BE185A79C; Tue, 20 Sep 2022 19:06:21 +0000 (UTC) Received: from fuller.cnet (ovpn-112-2.gru2.redhat.com [10.97.112.2]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 9A4D71759F; Tue, 20 Sep 2022 19:06:21 +0000 (UTC) Received: by fuller.cnet (Postfix, from userid 1000) id 6F905416D5C1; Tue, 20 Sep 2022 15:33:55 -0300 (-03) Date: Tue, 20 Sep 2022 15:33:55 -0300 From: Marcelo Tosatti To: Vitaly Kuznetsov Cc: qemu-devel@nongnu.org, Paolo Bonzini , Oliver Upton , Maxim Levitsky Subject: Re: [PATCH] i386: Fix KVM_CAP_ADJUST_CLOCK capability check Message-ID: References: <20220920144024.3559708-1-vkuznets@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220920144024.3559708-1-vkuznets@redhat.com> X-Scanned-By: MIMEDefang 3.1 on 10.11.54.5 Received-SPF: pass client-ip=170.10.133.124; envelope-from=mtosatti@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, T_SPF_TEMPERROR=0.01 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" On Tue, Sep 20, 2022 at 04:40:24PM +0200, Vitaly Kuznetsov wrote: > 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) > -- > 2.37.3 > > ACK.