Re: [Qemu-devel] [PATCH v2 06/13] hw/misc/tz-mpc.c: Implement registers

[Peter Maydell]

On 14 June 2018 at 21:14, Auger Eric <address@hidden> wrote:
> Hi Peter,
>
> On 06/04/2018 05:29 PM, Peter Maydell wrote:
>> Implement the missing registers for the TZ MPC.
>>
>> Signed-off-by: Peter Maydell <address@hidden>

>>  static MemTxResult tz_mpc_reg_read(void *opaque, hwaddr addr,
>>                                     uint64_t *pdata,
>>                                     unsigned size, MemTxAttrs attrs)
>>  {
>> +    TZMPC *s = TZ_MPC(opaque);
>>      uint64_t r;
>>      uint32_t offset = addr & ~0x3;
> I don't get where do we check if the access is secure or not. Shouldn't
> we test attrs.secure somewhere (PPROT[1] == 0)? Also the spec says
> IDregs can be read by any type of access. Where is this differentiation
> done?

I'd missed that bit of the spec -- yes, we should be checking
attrs.secure to see if we should allow access to the non-ID registers.
For the MPS2 boards it doesn't matter because the registers are
in a part of the memory map that is enforced as secure-access-only
by the IDAU.

thanks
-- PMM