Re: New CPUID/MSR driver; virtualization hooks

[Zachary Amsden <zach@vmware.com>]

H. Peter Anvin wrote:
> I have finally gotten off the pot and finished writing up my new 
> CPUID/MSR driver, which contains support for registers that need 
> arbitrary GPRs touched.  For i386 vs x86-64 compatibility, both use an 
> x86-64 register image (16 64-bit register fields); this allows 32-bit 
> userspace to access the full 64-bit image if the kernel is 64 bits.
>
> Anyway, this presumably requires new paravirtualization hooks.  The 
> patch is at:
>
> http://www.kernel.org/pub/linux/kernel/people/hpa/new-cpuid-msr.patch
>   
The requested URL /pub/linux/kernel/people/hpa/new-cpuid-msr.patch was 
not found on this server.

> ... and a git tree is at ...
>
> http://git.kernel.org/?p=linux/kernel/git/hpa/linux-2.6-cpuidmsr.git;a=summary
>
> I'm posting this here to give the paravirt maintainers an opportunity to 
> comment.  Presumably the functions that need to be paravirtualized are 
> the ones represented by the functions do_cpuid(), do_rdmsr() and
>   

rdmsr / wrmsr can be dropped from paravirt-ops; at least for us (they 
will trap and emulate just fine, and this driver is not performance 
critical), and I think for the others as well.  CPUID, however, does 
require a hook.

Zach