On 25 September 2012 18:00, Will Deacon [off-list ref] wrote:

On Sat, Sep 15, 2012 at 04:35:33PM +0100, Christoffer Dall wrote:

quoted

 ENTRY(__kvm_tlb_flush_vmid)
+       hvc     #0                      @ Switch to Hyp mode
+       push    {r2, r3}
+
+       add     r0, r0, #KVM_VTTBR
+       ldrd    r2, r3, [r0]
+       mcrr    p15, 6, r2, r3, c2      @ Write VTTBR
+       isb
+       mcr     p15, 0, r0, c8, c3, 0   @ TLBIALLIS (rt ignored)
+       dsb
+       isb
+       mov     r2, #0
+       mov     r3, #0
+       mcrr    p15, 6, r2, r3, c2      @ Back to VMID #0
+       isb

Do you need this isb, given that you're about to do an hvc?

quoted

+       pop     {r2, r3}
+       hvc     #0                      @ Back to SVC
        bx      lr

...you probably don't want to do the memory accesses involved
in the 'pop' under the wrong VMID ?

-- PMM