Re: Standardizing an MSR or other hypercall to get an RNG seed?

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Fri, Sep 19, 2014 at 10:36 AM, H. Peter Anvin <hpa@xxxxxxxxx> wrote:
> On 09/19/2014 10:21 AM, Andy Lutomirski wrote:
>>>
>>> There is a huge disadvantage to the fact that CPUID is a user space
>>> instruction, though.
>>
>> We can always make cpuid on the leaf in question return all zeros if CPL > 0.
>>
>
> Not sure that is better...

It's better than #GP...

This is why I prefer rdmsr: the privilege semantics are already
appropriate.  Also, I wouldn't be surprised if shoehorning
non-constant results into cpuid implementations might be awkward for
some hypervisors.

--Andy
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [KVM ARM]     [KVM ia64]     [KVM ppc]     [Virtualization Tools]     [Spice Development]     [Libvirt]     [Libvirt Users]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite Questions]     [Linux Kernel]     [Linux SCSI]     [XFree86]
  Powered by Linux