From patchwork Sat Feb 13 12:00:15 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: 8299851 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 4A3719F1E0 for ; Sat, 13 Feb 2016 12:00:54 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 9C9362021A for ; Sat, 13 Feb 2016 12:00:53 +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 F24C720204 for ; Sat, 13 Feb 2016 12:00:51 +0000 (UTC) Received: from localhost ([::1]:41445 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aUYsc-0006Px-W8 for patchwork-qemu-devel@patchwork.kernel.org; Sat, 13 Feb 2016 07:00:51 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34358) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aUYsQ-0006Pm-J0 for qemu-devel@nongnu.org; Sat, 13 Feb 2016 07:00:39 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aUYsM-00082n-Cb for qemu-devel@nongnu.org; Sat, 13 Feb 2016 07:00:38 -0500 Received: from mailhub.sw.ru ([195.214.232.25]:14259 helo=relay.sw.ru) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aUYsM-00081P-0K for qemu-devel@nongnu.org; Sat, 13 Feb 2016 07:00:34 -0500 Received: from hades.sw.ru ([10.30.8.132]) by relay.sw.ru (8.13.4/8.13.4) with ESMTP id u1DBRx6f029738; Sat, 13 Feb 2016 14:28:00 +0300 (MSK) From: "Denis V. Lunev" To: Date: Sat, 13 Feb 2016 15:00:15 +0300 Message-Id: <1455364815-19586-1-git-send-email-den@openvz.org> X-Mailer: git-send-email 2.5.0 MIME-Version: 1.0 X-MIME-Autoconverted: from 8bit to quoted-printable by relay.sw.ru id u1DBRx6f029738 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 v2 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" --- 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 | 3 +++ 1 file changed, 3 insertions(+) diff --git a/target-i386/kvm.c b/target-i386/kvm.c index 94024bc..63dee9c 100644 --- a/target-i386/kvm.c +++ b/target-i386/kvm.c @@ -639,6 +639,9 @@ int kvm_arch_init_vcpu(CPUState *cs) if (cpu->hyperv_crash && has_msr_hv_crash) { c->edx |= HV_X64_GUEST_CRASH_MSR_AVAILABLE; } + if (MACHINE_GET_CLASS(current_machine)->hot_add_cpu != NULL) { + c->edx |= HV_X64_CPU_DYNAMIC_PARTITIONING_AVAILABLE; + } if (cpu->hyperv_reset && has_msr_hv_reset) { c->eax |= HV_X64_MSR_RESET_AVAILABLE; }