From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49718) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aRIOL-0008B7-4B for qemu-devel@nongnu.org; Thu, 04 Feb 2016 06:48:09 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aRIOK-0000Hl-BX for qemu-devel@nongnu.org; Thu, 04 Feb 2016 06:48:05 -0500 Received: from mx1.redhat.com ([209.132.183.28]:40184) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aRIOK-0000Hf-6e for qemu-devel@nongnu.org; Thu, 04 Feb 2016 06:48:04 -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 CB1593C88C9 for ; Thu, 4 Feb 2016 11:48:03 +0000 (UTC) From: Igor Mammedov Date: Thu, 4 Feb 2016 12:47:35 +0100 Message-Id: <1454586455-10202-9-git-send-email-imammedo@redhat.com> In-Reply-To: <1454586455-10202-1-git-send-email-imammedo@redhat.com> References: <1454586455-10202-1-git-send-email-imammedo@redhat.com> Subject: [Qemu-devel] [PATCH 9/9] 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: pbonzini@redhat.com, ehabkost@redhat.com, mst@redhat.com Signed-off-by: Igor Mammedov --- 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 d6cd06a..2cc3fff 100644 --- a/hw/i386/acpi-build.c +++ b/hw/i386/acpi-build.c @@ -361,6 +361,12 @@ build_madt(GArray *table_data, GArray *linker, if (id.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