From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59929) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bKgA1-00048s-AW for qemu-devel@nongnu.org; Wed, 06 Jul 2016 02:18:14 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bKg9v-0003ID-Bd for qemu-devel@nongnu.org; Wed, 06 Jul 2016 02:18:12 -0400 Received: from mx4-phx2.redhat.com ([209.132.183.25]:40738) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bKg9v-0003I1-1m for qemu-devel@nongnu.org; Wed, 06 Jul 2016 02:18:07 -0400 Date: Wed, 6 Jul 2016 02:18:04 -0400 (EDT) From: Paolo Bonzini Message-ID: <234271213.4215596.1467785884526.JavaMail.zimbra@redhat.com> In-Reply-To: <20160706012619.ebiizdoqngkmur7a@hz-desktop> References: <20160622065324.23812-1-haozhong.zhang@intel.com> <20160706012619.ebiizdoqngkmur7a@hz-desktop> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [SeaBIOS] [PATCH v3] fw/msr_feature_control: add support to set MSR_IA32_FEATURE_CONTROL List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Haozhong Zhang Cc: Laszlo Ersek , seabios@seabios.org, qemu-devel@nongnu.org > I forgot to restore MSR_IA32_FEATURE_CONTROL in the resume path, and > MSR_IA32_FEATURE_CONTROL is zero after S3 resume. This is a bug. Sorry Laszlo. :) > Not restore MSR_IA32_FEATURE_CONTROL during S3 resume does not affect > at least Linux guest (tested 4.5). Current QEMU may advise the guest > firmware to set bit 20 (for LMCE), bit 2 (for VMX) and bit 0 (lock > bit). > - For LMCE, Linux only checks bit 20 and bit 0 at boot time and then > keeps using the result even after resume. On real hardware, LMCE would not be enabled after resume. I'm not sure what would happen, but it wouldn't be good. Paolo