Virtualization + CPU w/crypto acceleration instructions

Virtualization + CPU w/crypto acceleration instructions

[Molle Bestefich]

In a virtualized environment running Xen or VMware, can the guest
operating systems utilize hardware crypto acceleration such as the
"PadLock" AES acceleration built into VIA CPUs?

(Wasn't able to find this info in any of ~400 Google hits, so I'm
shooting it out a bit to let as many as possible benefit from the
answer.)

Re: Virtualization + CPU w/crypto acceleration instructions

[Jeremy Fitzhardinge]

Molle Bestefich wrote:
> In a virtualized environment running Xen or VMware, can the guest
> operating systems utilize hardware crypto acceleration such as the
> "PadLock" AES acceleration built into VIA CPUs?
>   

If they're unprivileged instructions, then they should just work.  If
its done via MSRs or some other ring0 mechanism, it might be more tricky.

    J

RE: Virtualization + CPU w/crypto acceleration instructions

[Kraska, Joe A (US SSA)]

This seems more like a developer question. You might try the xen-devel
list. Anyway, I believe that all hardware instructions on any x86 cpu
are supposed to be executable by arbitrary assembly. Those that cannot
be properly kernel trapped may experience performance loss, but I
think that's SUPPOSED to be the only limitation.

Would be nice if someone with exact knowledge chipped in, of course.

Joe.

> -----Original Message-----
> From: xen-users-bounces@lists.xensource.com [mailto:xen-users-
> bounces@lists.xensource.com] On Behalf Of Molle Bestefich
> Sent: Monday, March 12, 2007 12:36 PM
> To: xen-users@lists.xensource.com; virtualization@lists.osdl.org
> Subject: [Xen-users] Virtualization + CPU w/crypto acceleration
instructions
> 
> In a virtualized environment running Xen or VMware, can the guest
> operating systems utilize hardware crypto acceleration such as the
> "PadLock" AES acceleration built into VIA CPUs?
> 
> (Wasn't able to find this info in any of ~400 Google hits, so I'm
> shooting it out a bit to let as many as possible benefit from the
> answer.)
> 
> _______________________________________________
> Xen-users mailing list
> Xen-users@lists.xensource.com
> http://lists.xensource.com/xen-users

Re: Virtualization + CPU w/crypto acceleration instructions

[Zachary Amsden]

Molle Bestefich wrote:
> In a virtualized environment running Xen or VMware, can the guest
> operating systems utilize hardware crypto acceleration such as the
> "PadLock" AES acceleration built into VIA CPUs?

VMware doesn't support VIA CPUs, and I think we would have compatibility 
issues with these instructions.  In general, most hypervisors would need 
to support decoding of the new instructions for complete emulation in 
various fault and corner cases.  In general, I would expect some trouble 
just running a hypervisor or VIA CPUs, as the test matrix is so low I 
can't point even to one working example.  Perhaps someone can correct me 
if they have got one up and running.

UML should work fine though.

Zach

Re: Virtualization + CPU w/crypto acceleration instructions

[Jeremy Fitzhardinge]

Zachary Amsden wrote:
> VMware doesn't support VIA CPUs, and I think we would have compatibility 
> issues with these instructions.  In general, most hypervisors would need 
> to support decoding of the new instructions for complete emulation in 
> various fault and corner cases. 

Using a crypto instruction to update a pagetable would be... interesting ;)

    J