Re: Bull Mountain (IvyBridge +) random number generator

On Fri, Oct 12, 2012 at 10:50:55AM +0200, Harald Schmalzbauer wrote:
>  schrieb Konstantin Belousov am 02.09.2012 12:34 (localtime):
> > It is relatively well known that Ivy Bridge CPUs (Core iX 3XXX) have
> > built-in hardware random number generator, which is claimed to be both
> > very fast and high quality. Generator is accessible using non-privileged
> > RDRAND instruction. It is claimed that CPU performs sanitization of the
> > random sequence. In particular, it seems that paranoid AES encryption of
> > the raw random stream, performed by our padlock driver, is not needed
> > for Bull Mountain (there are hints that hardware performs it already).
> >
> > See
> > http://spectrum.ieee.org/computing/hardware/behind-intels-new-randomnumber-generator/0
> > http://software.intel.com/en-us/articles/intel-digital-random-number-generator-drng-software-implementation-guide/
> > and IA32 ADM.
> >
> > Patch at
> > http://people.freebsd.org/~kib/misc/bull_mountain.2.patch
> > implements support for the generator. I do not own any IvyBridge machines,
> > so I cannot test. Patch makes both padlock and bull generators the options,
> > you need to enable IVY_RNG to get support for the generator.
> >
> > I would be interested in seeing reports including verbose boot dmesg,
> > and some tests of /dev/random quality on the IvyBridge machines, you can
> > start with http://lists.gnupg.org/pipermail/gnupg-devel/2000-March/016328.html.
> 
> Thanks a lot for implementing this!
> I have an ESXi host with Ivy Brindge CPU.
> FreeBSD guest reports the following:
> CPU: Intel(R) Xeon(R) CPU E3-1270 V2 _at_ 3.50GHz (3492.07-MHz K8-class CPU)
>   Origin = "GenuineIntel"  Id = 0x306a9  Family = 6  Model = 3a 
> Stepping = 9
>  
> Features=0x1fa3fbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,DTS,MMX,FXSR,SSE,SSE2,SS,HTT>
>  
> Features2=0xfeba2203<SSE3,PCLMULQDQ,SSSE3,CX16,PCID,SSE4.1,SSE4.2,x2APIC,POPCNT,AESNI,XSAVE,OSXSAVE,AVX,F16C,RDRAND,HV>
>   AMD Features=0x28100800<SYSCALL,NX,RDTSCP,LM>
>   AMD Features2=0x1<LAHF>
>   TSC: P-state invariant
> real memory  = 8589934592 (8192 MB)
> avail memory = 8235110400 (7853 MB)
> Event timer "LAPIC" quality 600
> ACPI APIC Table: <PTLTD       APIC  >
> FreeBSD/SMP: Multiprocessor System Detected: 4 CPUs
> FreeBSD/SMP: 1 package(s) x 4 core(s)
>  cpu0 (BSP): APIC ID:  0
>  cpu1 (AP): APIC ID:  1
>  cpu2 (AP): APIC ID:  2
>  cpu3 (AP): APIC ID:  3
> MADT: Forcing active-low polarity and level trigger for SCI
> 
> But unfortunately accessing /dev/random doesn't work with IVY_RNG enabled.
> 'dd' consumes 100% wcpu bound to one core but never finishes (dd
> if=/dev/random bs=1k count=100|./ent)
> Also some other functions are blocked, logging in for example (doesn't
> matter if it's console or ssh). But I can walk arround in already
> established sessions.
> 
> I made a 9.1-RC-2 debug kernel but no info appears. Also IVY_RNG isn't
> reported after kldloading, nor during boot, but this is the expected
> behaviour if I unterstand your patch correctly.
> 
> I guess using RDRAND in an hypervisor environment should make no
> difference but please correct me if I'm wrong.

Try the stable/9 instead. The code was merged in r240950.
There was a bug in the original patch with the similar description.