Re: [Qemu-devel] [PATCH v2 14/18] nvdimm: support NFIT_CMD_IMPLEMENTED function

[Xiao Guangrong <guangrong.xiao@linux.intel.com>]

On 08/28/2015 08:01 PM, Stefan Hajnoczi wrote:
> On Wed, Aug 26, 2015 at 06:46:35PM +0800, Xiao Guangrong wrote:
>> On 08/26/2015 12:23 AM, Stefan Hajnoczi wrote:
>>> On Fri, Aug 14, 2015 at 10:52:07PM +0800, Xiao Guangrong wrote:
>>>>   static void dsm_write(void *opaque, hwaddr addr,
>>>>                         uint64_t val, unsigned size)
>>>>   {
>>>> +    struct MemoryRegion *dsm_ram_mr = opaque;
>>>> +    struct dsm_buffer *dsm;
>>>> +    struct dsm_out *out;
>>>> +    void *buf;
>>>> +
>>>>       assert(val == NOTIFY_VALUE);
>>>
>>> The guest should not be able to cause an abort(3).  If val !=
>>> NOTIFY_VALUE we can do nvdebug() and then return.
>>
>> The ACPI code and emulation code both are from qemu, if that happens,
>> it's really a bug, aborting the VM is better than throwing a debug
>> message under this case to avoid potential data corruption.
>
> abort(3) is dangerous because it can create a core dump.  If a malicious
> guest triggers this repeatedly it could consume a lot of disk space and
> I/O or CPU while performing the core dumps.
>
> We cannot trust anything inside the guest, even if the guest code comes
> from QEMU because a malicious guest can still read/write to the same
> hardware registers.
>

Completely agree with you. :)

How about use exit{1} instead of abort() to kill the VM?