From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [216.205.24.124]) by mx.groups.io with SMTP id smtpd.web09.8223.1635227442453214156 for ; Mon, 25 Oct 2021 22:50:43 -0700 Authentication-Results: mx.groups.io; dkim=pass header.i=@redhat.com header.s=mimecast20190719 header.b=X7Qh0vVa; spf=pass (domain: redhat.com, ip: 216.205.24.124, mailfrom: kraxel@redhat.com) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1635227441; 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=cx7aZXfoEwZvvMaSajfe+reeBBBdqISBnyBjR28agSk=; b=X7Qh0vVasOV60doPVJgeHtWBVG2Ym2jKJXqrgYVe52UR3aSCzQyP5nc3h+iq0gsyd4X7qo B/eiW+w405wg5plx7o243qhei9n7oPZm135KblAKZO5QPpeG1MdIvVLSwlbeDs10hF2DNn WnOffdXy0G0vgmO/UFNVJD16jo2nbQM= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-341-BKqok8yNOLOTAR-uMLnF7Q-1; Tue, 26 Oct 2021 01:50:39 -0400 X-MC-Unique: BKqok8yNOLOTAR-uMLnF7Q-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 03823100C609; Tue, 26 Oct 2021 05:50:38 +0000 (UTC) Received: from sirius.home.kraxel.org (unknown [10.39.192.23]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 6A83B19811; Tue, 26 Oct 2021 05:50:37 +0000 (UTC) Received: by sirius.home.kraxel.org (Postfix, from userid 1000) id A53F518007A6; Tue, 26 Oct 2021 07:50:35 +0200 (CEST) Date: Tue, 26 Oct 2021 07:50:35 +0200 From: "Gerd Hoffmann" To: "Xu, Min M" Cc: "devel@edk2.groups.io" , Ard Biesheuvel , "Justen, Jordan L" , Brijesh Singh , Erdem Aktas , James Bottomley , "Yao, Jiewen" , Tom Lendacky Subject: Re: [edk2-devel] [PATCH V2 28/28] OvmfPkg: Add LocalApicTimerDxe Message-ID: <20211026055035.5xsfyoc2j64srqbf@sirius.home.kraxel.org> References: <20211012130207.zmx2yf5inpkoalqf@sirius.home.kraxel.org> <20211025112750.mytcbe3yawtidj7q@sirius.home.kraxel.org> MIME-Version: 1.0 In-Reply-To: X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=kraxel@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline > > I still think we don't need a runtime switch. Continue using 8254TimerDxe for > > CSM_ENABLE=TRUE builds should be enough. > > > Thanks for your detailed explanation. I agree we don't need a runtime switch. Just use CSM_ENABLE=TRUE in *.dsc/*.fdf to switch 8254 and lapic in build time. > I will submit a separate patch series for this change. > > There are 4 .dsc which include the 8254Timer. > - OvmfPkg/AmdSev/AmdSevX64.dsc > - OvmfPkg/OvmfPkgIa32.dsc > - OvmfPkg/OvmfPkgIa32X64.dsc > - OvmfPkg/OvmfPkgX64.dsc > > Do you think we should apply the changes to all above 4 .dsc? For the AmdSev config it doesn't make sense to support a CSM. So I' suggest to just remove support for CSM_ENABLE=TRUE (separate patch), then use the lapic timer unconditionally. For the three OvmfPkg* configs using 8254TimerDxe with CSM_ENABLE=TRUE and LapicTimerDxe otherwise is fine. take care, Gerd