[Qemu-ppc] [qemu-ppc] quesstion about kvm e500 tlb search method

[Wangkai (Kevin,C)]

Dear,

 

I check e500 core reference when the e500 core lookup for L2mmu entries,

TLB1 is preferred to TLB0.

 

And for e500 KVM l2mmu lookup, I find that TLB0 is searched first, and it

Was done by software.

 

And I suggest we can search TLB1 first, because TLB0 have more entries

Than TLB1, and this can improve the guest kernel performance very much.

 

Can I do this change to the kvm code? Is there some other affect?

 

Thanks!

Wangkai

 

 

int kvmppc_e500_tlb_search(struct kvm_vcpu *vcpu,

                            gva_t eaddr, unsigned int pid, int as)

{

       struct kvmppc_vcpu_e500 *vcpu_e500 = to_e500(vcpu);

       int esel, tlbsel;

 

       for (tlbsel = 0; tlbsel < 2; tlbsel++) {  // first tlb0, and then tlb1

              esel = kvmppc_e500_tlb_index(vcpu_e500, eaddr, tlbsel, pid, as);

              if (esel >= 0)

                     return index_of(tlbsel, esel);

       }

 

       return -1;

}