[libvirt] [PATCH] qemu: Allow /dev/dri/renderD128

[Michal Privoznik]

On 02/08/2017 10:31 AM, Daniel P. Berrange wrote:
> On Wed, Feb 08, 2017 at 10:26:26AM +0100, Michal Privoznik wrote:
>> This demand comes from qemu_egl_rendernode_open() in qemu source
>> code. It is needed for virgl to work with qemu:///system
>> connection. The session one works just fine.
>>
>> Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
>> ---
>>  docs/drvqemu.html.in               | 1 +
>>  src/qemu/qemu.conf                 | 3 ++-
>>  src/qemu/qemu_cgroup.c             | 1 +
>>  src/qemu/test_libvirtd_qemu.aug.in | 1 +
>>  4 files changed, 5 insertions(+), 1 deletion(-)
> 
>> diff --git a/src/qemu/qemu_cgroup.c b/src/qemu/qemu_cgroup.c
>> index 6c90d46d1..b47f714fc 100644
>> --- a/src/qemu/qemu_cgroup.c
>> +++ b/src/qemu/qemu_cgroup.c
>> @@ -47,6 +47,7 @@ const char *const defaultDeviceACL[] = {
>>      "/dev/random", "/dev/urandom",
>>      "/dev/ptmx", "/dev/kvm", "/dev/kqemu",
>>      "/dev/rtc", "/dev/hpet", "/dev/vfio/vfio",
>> +    "/dev/dri/renderD128",
> 
> Surely this is only needed in very specific scenarios. ie with
> the virtio-vga 3d rendering enabled.
> 
> Allowing unconditional access to the DRI devices is a big
> wide open door from security POV, for something few VMs
> will ever need.
> 
> The global device whitelist is only for devices that we
> expect every QEMU to unconditionally require.

I can argue the same about /dev/vfio/vfio and yet we have it on the list.

Michal