Re: [PATCH 11/12] svcrdma: Add a message log string to indicate if FastReg is being used

[Tom Tucker <tom@opengridcomputing.com>]

Tom Tucker wrote:
> J. Bruce Fields wrote:
>> On Thu, Oct 09, 2008 at 01:46:43PM -0500, Tom Tucker wrote:
>>  
>>> Coming up with a name for the command is probably
>>> harder than writing it.
>>>
>>> Here it is...
>>>     
>>
>> Neat-o, thanks.
>>
>> Just for fun, I installed libibverbs from Fedora 9, modprobe'd
>> ib_uverbs, and tried running this, and got a "libibverbs: Warning:
>> couldn't open config directory '/etc/libibverbs.d'."  Is there a HOWTO
>> somewhere that I should know about?
>>   
> Hmm. Sounds like the Fedora RPM didn't do all the necessary bits. I 
> have a Fedora 9 system,
> I'll see what I get. I typically use the latest OFED distro.
>

I should qualify this. I use the OFED distro for the user-mode bits. For 
kernel bits, I use top of
tree.

Thanks,
Tom

> Tom
>> --b.
>>
>>  
>>> #include <stdlib.h>
>>> #include <stdio.h>
>>> #include <infiniband/verbs.h>
>>>
>>> #define FAST_REG (1<<21) /* This will be in infiniband/verbs.h in 
>>> the future */
>>>
>>> static char *safety_string(struct ibv_device_attr *a, struct 
>>> ibv_device *dev)
>>> {
>>>         if (a->device_cap_flags & FAST_REG
>>>             || dev->transport_type == IBV_TRANSPORT_IB)
>>>                 return "Safe. NFSRDMA exposes only RPC memory.\n";
>>>         else
>>>                 return "Unsafe. NFSRDMA exposes Server memory.\n";
>>> }
>>>
>>> int main(int argc, char *argv[])
>>> {
>>>         struct ibv_device **dev_list;
>>>         struct ibv_context *context;
>>>         struct ibv_device_attr attr;
>>>         int dev_count;
>>>         int i;
>>>
>>>         dev_list = ibv_get_device_list(&dev_count);
>>>         for (i = 0; dev_list && i < dev_count; i++) {
>>>                 printf("%-20s: ", ibv_get_device_name(dev_list[i]));
>>>                 context = ibv_open_device(dev_list[i]);
>>>                 if (!context) {
>>>                         printf("could not open device\n");
>>>                         continue;
>>>                 }
>>>                 if (!ibv_query_device(context, &attr))
>>>                         printf("%s\n", safety_string(&attr, 
>>> dev_list[i]));
>>>                 else
>>>                         printf("could not query device\n");
>>>
>>>                 ibv_close_device(context);
>>>         }
>>>         if (dev_list)
>>>                 ibv_free_device_list(dev_list);
>>>
>>>         exit(0);
>>> }
>>>
>>>    
>>>> The one drawback is that it wouldn't be able to tell whether the
>>>> currently running kernel actually supported fast registration.  Do you
>>>> think a guess based on kernel version would be good enough for that?
>>>>
>>>>       
>>> I do, yes.
>>>
>>>    
>>>>> This code makes devices more secure than they used to be. So there 
>>>>> is no  negative security regression here. This patchset simply 
>>>>> improves the security for newer devices that support the new 
>>>>> features.
>>>>>         
>>>> Yes, agreed.  Just to be clear, I *have* queued up all but these last
>>>> two patches (the printk and documentation patches) for 2.6.28. 
>>>>       
>>> Ok, thanks.
>>>
>>>    
>>>> --b.
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>
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