From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35254) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fnhju-0003Ft-Qw for qemu-devel@nongnu.org; Thu, 09 Aug 2018 06:00:23 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fnhjr-0005s5-Oe for qemu-devel@nongnu.org; Thu, 09 Aug 2018 06:00:18 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:42954 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fnhjr-0005qk-J1 for qemu-devel@nongnu.org; Thu, 09 Aug 2018 06:00:15 -0400 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 mx1.redhat.com (Postfix) with ESMTPS id A604C40216E8 for ; Thu, 9 Aug 2018 10:00:14 +0000 (UTC) Date: Thu, 9 Aug 2018 12:00:11 +0200 From: Igor Mammedov Message-ID: <20180809120011.51023bf2@redhat.com> In-Reply-To: <20180808231636-mutt-send-email-mst@kernel.org> References: <1533741349-199141-1-git-send-email-imammedo@redhat.com> <1533741349-199141-4-git-send-email-imammedo@redhat.com> <20180808231636-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [RFC PATCH 3/4] pc: acpi: add _CST support List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" Cc: qemu-devel@nongnu.org On Wed, 8 Aug 2018 23:17:48 +0300 "Michael S. Tsirkin" wrote: > On Wed, Aug 08, 2018 at 05:15:48PM +0200, Igor Mammedov wrote: > > Reuse CPU hotplug IO registers for passing a CST entry > > containing package for shalowest C1 using mwait and > > read it out in guest with new CCST AML method. > > I don't see how 1 entry is enough. We need to describe full _CST package so > that guest can do reasonable power management on the CPU. I was assuming that CST are to be used for mwait/monitor idle combo to help reduce latencies/vmexits on cpus wakeup from idle state, hence 1 entry. It's trivial to add as much as needed entries though. If you are fine with approach I can respin patch with arbitrary number of CStates. > > The CState support is optional and could be turned on > > with '-global PIIX4_PM.cstate=on' CLI option. > > > > Signed-off-by: Igor Mammedov > > --- [...]