From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44854) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aZIvt-0006yI-2x for qemu-devel@nongnu.org; Fri, 26 Feb 2016 08:59:49 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aZIvq-0008Vy-SX for qemu-devel@nongnu.org; Fri, 26 Feb 2016 08:59:49 -0500 Received: from mx1.redhat.com ([209.132.183.28]:39186) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aZIvq-0008Vs-ND for qemu-devel@nongnu.org; Fri, 26 Feb 2016 08:59:46 -0500 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) by mx1.redhat.com (Postfix) with ESMTPS id 485258EA38 for ; Fri, 26 Feb 2016 13:59:46 +0000 (UTC) From: Igor Mammedov Date: Fri, 26 Feb 2016 14:59:27 +0100 Message-Id: <1456495168-144510-10-git-send-email-imammedo@redhat.com> In-Reply-To: <1456495168-144510-1-git-send-email-imammedo@redhat.com> References: <1456495168-144510-1-git-send-email-imammedo@redhat.com> Subject: [Qemu-devel] [PATCH v4 09/10] pc: acpi: clarify why possible LAPIC entries must be present in MADT List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: marcel@redhat.com, ehabkost@redhat.com, mst@redhat.com Signed-off-by: Igor Mammedov Reviewed-by: Eduardo Habkost --- hw/i386/acpi-build.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c index 48240e0..155198b 100644 --- a/hw/i386/acpi-build.c +++ b/hw/i386/acpi-build.c @@ -360,6 +360,12 @@ build_madt(GArray *table_data, GArray *linker, PCMachineState *pcms) if (apic_ids->cpus[i].cpu != NULL) { apic->flags = cpu_to_le32(1); } else { + /* ACPI spec says that LAPIC entry for non present + * CPU may be omitted from MADT or it must be marked + * as disabled. However omitting non present CPU from + * MADT breaks hotplug on linux. So possible CPUs + * should be put in MADT but kept disabled. + */ apic->flags = cpu_to_le32(0); } } -- 1.8.3.1