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

[Tom Tucker <tom@opengridcomputing.com>]

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.

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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