From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: [PATCH v2 uq/master] kvmvapic: Disable if there is insufficient memory Date: Tue, 14 Aug 2012 13:43:12 +0200 Message-ID: <502A39D0.7080702@siemens.com> References: <502A32BB.2000607@siemens.com> <87txw5itv9.fsf@blackfin.pond.sub.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Markus Armbruster , qemu-devel , kvm To: Avi Kivity , Marcelo Tosatti Return-path: Received: from goliath.siemens.de ([192.35.17.28]:23926 "EHLO goliath.siemens.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752080Ab2HNLnT (ORCPT ); Tue, 14 Aug 2012 07:43:19 -0400 In-Reply-To: <87txw5itv9.fsf@blackfin.pond.sub.org> Sender: kvm-owner@vger.kernel.org List-ID: We need at least 1M of RAM to map the option ROM. Otherwise, we will corrupt host memory or even crash: $ qemu-system-x86_64 -nodefaults --enable-kvm -vnc :0 -m 640k Segmentation fault (core dumped) Reported-and-tested-by: Markus Armbruster Signed-off-by: Jan Kiszka --- hw/apic_common.c | 4 +++- 1 files changed, 3 insertions(+), 1 deletions(-) diff --git a/hw/apic_common.c b/hw/apic_common.c index 58e63b0..371f95d 100644 --- a/hw/apic_common.c +++ b/hw/apic_common.c @@ -299,7 +299,9 @@ static int apic_init_common(SysBusDevice *dev) sysbus_init_mmio(dev, &s->io_memory); - if (!vapic && s->vapic_control & VAPIC_ENABLE_MASK) { + /* Note: We need at least 1M to map the VAPIC option ROM */ + if (!vapic && s->vapic_control & VAPIC_ENABLE_MASK && + ram_size >= 1024 * 1024) { vapic = sysbus_create_simple("kvmvapic", -1, NULL); } s->vapic = vapic; -- 1.7.3.4