[PATCH 1/5] KVM: PPC: e500: Move VCPU's MMUCFG register initialization earlier

[Alexander Graf]

On 31.01.2013, at 15:56, Caraman Mihai Claudiu-B02008 wrote:

>> -----Original Message-----
>> From: Alexander Graf [mailto:agraf at suse.de]
>> Sent: Thursday, January 31, 2013 3:21 PM
>> To: Caraman Mihai Claudiu-B02008
>> Cc: kvm-ppc at vger.kernel.org; kvm at vger.kernel.org; linuxppc-
>> dev at lists.ozlabs.org
>> Subject: Re: [PATCH 1/5] KVM: PPC: e500: Move VCPU's MMUCFG register
>> initialization earlier
>> 
>> 
>> On 30.01.2013, at 14:29, Mihai Caraman wrote:
>> 
>>> VCPU's MMUCFG register initialization should not depend on
>> KVM_CAP_SW_TLB
>>> ioctl call. Move it earlier into tlb initalization phase.
>> 
>> Quite the contrary. The fact that there is an mfspr() in e500_mmu.c
>> already tells us that the code is broken. The TLB guest code should only
>> depend on input from the SW_TLB configuration. It's completely orthogonal
>> to the host capabilities.
> 
> Then we have the same issue for TLBnCFG registers which need to be configured
> via SW_TLB ioctl. What is the purpose of guest tlb initalization in e500_mmu.c
> if we rely on SW_TLB?

It's to provide a fallback to user space that doesn't implement SW_TLB configuration yet.


Alex