From mboxrd@z Thu Jan  1 00:00:00 1970
From: Marcelo Tosatti <mtosatti@redhat.com>
Subject: Re: [PATCH v2 uq/master] kvmvapic: Disable if there is insufficient
 memory
Date: Tue, 14 Aug 2012 16:01:23 -0300
Message-ID: <20120814190123.GB5281@amt.cnet>
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Cc: Avi Kivity <avi@redhat.com>, Markus Armbruster <armbru@redhat.com>,
	qemu-devel <qemu-devel@nongnu.org>, kvm <kvm@vger.kernel.org>
To: Jan Kiszka <jan.kiszka@siemens.com>
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On Tue, Aug 14, 2012 at 01:43:12PM +0200, Jan Kiszka wrote:
> 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 <armbru@redhat.com>
> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
> ---
>  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

Applied, thanks.