On 02/10/2012 11:22 PM, Marc Zyngier wrote:
> +ENTRY(__kvm_tlb_flush_vmid)
> + hvc #0 @ Switch to Hyp mode
> + push {r2, r3}
>
> + ldrd r2, r3, [r0, #KVM_VTTBR]
> + mcrr p15, 6, r2, r3, c2 @ Write VTTBR
> + isb
> + mcr p15, 0, r0, c8, c7, 0 @ TBLIALL
> + dsb
> + isb
> + mov r2, #0
> + mov r3, #0
> + mcrr p15, 6, r2, r3, c2 @ Back to VMID #0
> + isb
> +
> + pop {r2, r3}
> + hvc #0 @ Back to SVC
> + mov pc, lr
> +ENDPROC(__kvm_tlb_flush_vmid)
With the last VMID implementation, you could get the equivalent effect
of a per-VMID flush, by just getting a new VMID for the current VM. So
you could do a (kvm->arch.vmid = 0) to force a new VMID when the guest
reruns, and save the overhead of that flush (you will do a complete
flush every 255 times instead of a small one every single time).
Best regards,
Antonios
