Patchwork [v2,uq/master] kvmvapic: Disable if there is insufficient memory

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Submitter Jan Kiszka
Date Aug. 14, 2012, 11:43 a.m.
Message ID <502A39D0.7080702@siemens.com>
Download mbox | patch
Permalink /patch/177233/
State New
Headers show

Comments

Jan Kiszka - Aug. 14, 2012, 11:43 a.m.
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(-)
Marcelo Tosatti - Aug. 14, 2012, 7:01 p.m.
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.

Patch

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;