From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58962) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fSoK3-00077q-LU for qemu-devel@nongnu.org; Tue, 12 Jun 2018 14:47:16 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fSoK0-0005Jq-Gu for qemu-devel@nongnu.org; Tue, 12 Jun 2018 14:47:15 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:45222 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 1fSoK0-0005Jk-CD for qemu-devel@nongnu.org; Tue, 12 Jun 2018 14:47:12 -0400 Date: Tue, 12 Jun 2018 21:47:11 +0300 From: "Michael S. Tsirkin" Message-ID: <20180612184616.90838-1-mst@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Subject: [Qemu-devel] [PATCH v2 0/2] kvm: x86 CPU power management List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Paolo Bonzini , Richard Henderson , Eduardo Habkost , Marcelo Tosatti , kvm@vger.kernel.org This adds ability to expose host CPU power management capabilities to guests. For intel guests, this is sufficient for guest to enable low power CPU power management. For AMD guests it isn't sufficient, deeper C-states are entered using System-IO. mwait based power management is tied closely to specifics of CPUID, making migration challenging. At this point only the non-migrateable -cpu host is supported. With this patch applied, VM latency is within the noise of baremetal for some benchmarks. perf bench sched pipe results: Before: 6.452 sec After: 4.382 sec Baremetal: 4.136 sec Michael S. Tsirkin (2): kvm: support -realtime cpu-pm=on|off i386/cpu: make -cpu host support monitor/mwait include/sysemu/sysemu.h | 1 + target/i386/cpu.h | 9 +++++++++ target/i386/cpu.c | 19 ++++++++++++++----- target/i386/kvm.c | 30 ++++++++++++++++++++++++++++++ vl.c | 6 ++++++ qemu-options.hx | 9 +++++++-- 6 files changed, 67 insertions(+), 7 deletions(-) -- MST