From patchwork Mon Feb 22 09:13:02 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: "Denis V. Lunev" X-Patchwork-Id: 8373421 Return-Path: X-Original-To: patchwork-qemu-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 19B939F1D4 for ; Mon, 22 Feb 2016 09:13:33 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 78A02203A1 for ; Mon, 22 Feb 2016 09:13:32 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 634EA2039E for ; Mon, 22 Feb 2016 09:13:31 +0000 (UTC) Received: from localhost ([::1]:47898 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aXmYc-0006FQ-Oq for patchwork-qemu-devel@patchwork.kernel.org; Mon, 22 Feb 2016 04:13:30 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49096) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aXmYS-0006F9-8T for qemu-devel@nongnu.org; Mon, 22 Feb 2016 04:13:21 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aXmYP-0005Me-1l for qemu-devel@nongnu.org; Mon, 22 Feb 2016 04:13:20 -0500 Received: from mailhub.sw.ru ([195.214.232.25]:44399 helo=relay.sw.ru) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aXmYO-0005Le-M1 for qemu-devel@nongnu.org; Mon, 22 Feb 2016 04:13:16 -0500 Received: from irbis.sw.ru ([10.24.38.119]) by relay.sw.ru (8.13.4/8.13.4) with ESMTP id u1M9D2EH013582; Mon, 22 Feb 2016 12:13:03 +0300 (MSK) From: "Denis V. Lunev" To: Date: Mon, 22 Feb 2016 12:13:02 +0300 Message-Id: <1456132382-25327-1-git-send-email-den@openvz.org> X-Mailer: git-send-email 2.1.4 MIME-Version: 1.0 X-MIME-Autoconverted: from 8bit to quoted-printable by relay.sw.ru id u1M9D2EH013582 X-detected-operating-system: by eggs.gnu.org: OpenBSD 3.x X-Received-From: 195.214.232.25 Cc: Eduardo Habkost , qemu-devel@nongnu.org, Paolo Bonzini , "Denis V. Lunev" , =?UTF-8?q?Andreas=20F=C3=A4rber?= , Richard Henderson Subject: [Qemu-devel] [PATCH v3 1/1] hyperv: cpu hotplug fix with HyperV enabled X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP With Hyper-V enabled CPU hotplug stops working. The CPU appears in device manager on Windows but does not appear in peformance monitor and control panel. The root of the problem is the following. Windows checks HV_X64_CPU_DYNAMIC_PARTITIONING_AVAILABLE bit in CPUID. The presence of this bit is enough to cure the situation. The bit should be set when CPU hotplug is allowed for HyperV VM. The check that hot_add_cpu callback is defined is enough from the protocol point of view. Though this callback is defined almost always thus there is no need to export that knowledge in the other way. Signed-off-by: Denis V. Lunev Reviewed-by: Roman Kagan CC: Paolo Bonzini CC: Richard Henderson CC: Eduardo Habkost CC: "Andreas Färber" Reviewed-by: Eduardo Habkost --- Changes from v2: - bit set unconditionally upon the discussion Changes from v1: - dropped command line option and set the bit if HyperV is enabled and hot_add_cpu callback is present target-i386/kvm.c | 1 + 1 file changed, 1 insertion(+) diff --git a/target-i386/kvm.c b/target-i386/kvm.c index 7974acb..08d6444 100644 --- a/target-i386/kvm.c +++ b/target-i386/kvm.c @@ -639,6 +639,7 @@ int kvm_arch_init_vcpu(CPUState *cs) if (cpu->hyperv_crash && has_msr_hv_crash) { c->edx |= HV_X64_GUEST_CRASH_MSR_AVAILABLE; } + c->edx |= HV_X64_CPU_DYNAMIC_PARTITIONING_AVAILABLE; if (cpu->hyperv_reset && has_msr_hv_reset) { c->eax |= HV_X64_MSR_RESET_AVAILABLE; }