From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48040) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1afZ4r-000761-7R for qemu-devel@nongnu.org; Mon, 14 Mar 2016 16:26:58 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1afZ4q-0004lP-1m for qemu-devel@nongnu.org; Mon, 14 Mar 2016 16:26:57 -0400 Received: from mx1.redhat.com ([209.132.183.28]:52509) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1afZ4p-0004lL-SV for qemu-devel@nongnu.org; Mon, 14 Mar 2016 16:26:55 -0400 From: Eduardo Habkost Date: Mon, 14 Mar 2016 17:26:47 -0300 Message-Id: <1457987208-18968-2-git-send-email-ehabkost@redhat.com> In-Reply-To: <1457987208-18968-1-git-send-email-ehabkost@redhat.com> References: <1457987208-18968-1-git-send-email-ehabkost@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Subject: [Qemu-devel] [PULL 1/2] hyperv: cpu hotplug fix with HyperV enabled List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Maydell Cc: qemu-devel@nongnu.org, Paolo Bonzini , "Denis V. Lunev" , =?UTF-8?q?Andreas=20F=C3=A4rber?= , Richard Henderson From: "Denis V. Lunev" 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 F=C3=A4rber" Reviewed-by: Eduardo Habkost Signed-off-by: Eduardo Habkost --- 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 |=3D HV_X64_GUEST_CRASH_MSR_AVAILABLE; } + c->edx |=3D HV_X64_CPU_DYNAMIC_PARTITIONING_AVAILABLE; if (cpu->hyperv_reset && has_msr_hv_reset) { c->eax |=3D HV_X64_MSR_RESET_AVAILABLE; } --=20 2.1.0