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.web08.981.1608563028271506925 for ; Mon, 21 Dec 2020 07:03:48 -0800 Authentication-Results: mx.groups.io; dkim=pass header.i=@redhat.com header.s=mimecast20190719 header.b=bRFT4Rg/; spf=pass (domain: redhat.com, ip: 216.205.24.124, mailfrom: lersek@redhat.com) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1608563027; 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=kV16VhxbrQkHXJNcZaU4onTbROw1fyi9cCC7DIPKLZw=; b=bRFT4Rg/aFQj8nGhYeXpfjKtIga7Hke4oW573XeuD6lU8H/V3ZAyuz2IscRKuBiFYhv8WS MzjDzfPw5mGj3G0+UZ3H9Ahz0uYrJ7YV8Lh32R+f2Z2hY0AysRvfck1PxIaCMETBaWwmbu wRg/a2NXMFGGvUdFOIptEHReehNWxto= 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-121-HuRm6CQOO8CnSB4RKckaWg-1; Mon, 21 Dec 2020 10:03:45 -0500 X-MC-Unique: HuRm6CQOO8CnSB4RKckaWg-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id BBFBA1007461; Mon, 21 Dec 2020 15:03:44 +0000 (UTC) Received: from lacos-laptop-7.usersys.redhat.com (ovpn-114-71.ams2.redhat.com [10.36.114.71]) by smtp.corp.redhat.com (Postfix) with ESMTP id C511A19714; Mon, 21 Dec 2020 15:03:42 +0000 (UTC) Subject: Re: [edk2-devel] [RFC PATCH 0/5] support CPU hot-unplug From: "Laszlo Ersek" To: devel@edk2.groups.io, ankur.a.arora@oracle.com Cc: imammedo@redhat.com, boris.ostrovsky@oracle.com References: <20201208053432.2690694-1-ankur.a.arora@oracle.com> <70e6bf5d-3d59-2e6f-4b5a-2e68cdda8108@redhat.com> Message-ID: <4a7f3357-06f7-3e47-e400-b59705594c34@redhat.com> Date: Mon, 21 Dec 2020 16:03:42 +0100 MIME-Version: 1.0 In-Reply-To: <70e6bf5d-3d59-2e6f-4b5a-2e68cdda8108@redhat.com> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=lersek@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit On 12/21/20 15:44, Laszlo Ersek wrote: > Hi Ankur, > > On 12/08/20 06:34, Ankur Arora wrote: >> [ Resending to the correct edk2 alias this time. ] >> >> Hi, >> >> This series adds support for CPU hot-unplug with OVMF. >> >> Please see this in conjunction with the QEMU v2 series posted here: >> https://lore.kernel.org/qemu-devel/20201207140739.3829993-1-imammedo@redhat.com/ >> >> In particular, would be glad for comments on Patch 4, specifically >> where we should be ejecting the CPU. >> >> Right now the ejection happens in UnplugCpus() (called from >> CpuHotplugMmi()): >> + QemuCpuhpWriteCpuSelector (mMmCpuIo, RemoveApicId); >> + QemuCpuhpWriteCpuStatus (mMmCpuIo, QEMU_CPUHP_STAT_EJECTED); >> >> That is way too early -- given that the actual unplug will happen >> in SmmCpuUpdate() and given that the BSPHandler() would have waited >> for the APs multiple times before then. >> >> Another possibility is that the actual ejection be deferred to the >> _EJ0 method after the return from the SMI. But, that seems like a >> hack. Additionally, Igor points out here that this approach has problems: >> https://lore.kernel.org/qemu-devel/20201204170939.1815522-1-imammedo@redhat.com/ > > I've filed: > > https://bugzilla.tianocore.org/show_bug.cgi?id=3132 > > Can you please register an account in the TianoCore Bugzilla at > , and assign the above ticket to yourself? > > And then, the URL of the new BZ ticket should be included in every > commit message, like this: > > Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=3132 > > just above your S-o-b. > > No need to repost just because of this; I'll review the RFC series later. I've also listed under . Thanks Laszlo