Re: [Qemu-devel] [PATCH 3/7] target-arm: Use access_trap_aa32s_el1() for SCR and MVBAR

["Edgar E. Iglesias" <edgar.iglesias@gmail.com>]

On Wed, Feb 03, 2016 at 01:38:37PM +0000, Peter Maydell wrote:
> The registers MVBAR and SCR should have the behaviour of trapping to
> EL3 if accessed from Secure EL1, but we were incorrectly implementing
> them to UNDEF (which would trap to EL1).  Fix this by using the new
> access_trap_aa32s_el1() access function.

Hi,

It seems to me like if EL3 is running in AArch32, then we shouldn't
trap accesses from Secure EL1 but I can't find that logic. Am I missing
something?

Cheers,
Edgar


> 
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
>  target-arm/helper.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/target-arm/helper.c b/target-arm/helper.c
> index 8b96b80..d85b04f 100644
> --- a/target-arm/helper.c
> +++ b/target-arm/helper.c
> @@ -3547,7 +3547,8 @@ static const ARMCPRegInfo el3_cp_reginfo[] = {
>        .resetvalue = 0, .writefn = scr_write },
>      { .name = "SCR",  .type = ARM_CP_ALIAS,
>        .cp = 15, .opc1 = 0, .crn = 1, .crm = 1, .opc2 = 0,
> -      .access = PL3_RW, .fieldoffset = offsetoflow32(CPUARMState, cp15.scr_el3),
> +      .access = PL1_RW, .accessfn = access_trap_aa32s_el1,
> +      .fieldoffset = offsetoflow32(CPUARMState, cp15.scr_el3),
>        .writefn = scr_write },
>      { .name = "MDCR_EL3", .state = ARM_CP_STATE_AA64,
>        .opc0 = 3, .opc1 = 6, .crn = 1, .crm = 3, .opc2 = 1,
> @@ -3569,7 +3570,8 @@ static const ARMCPRegInfo el3_cp_reginfo[] = {
>        .access = PL3_W | PL1_R, .resetvalue = 0,
>        .fieldoffset = offsetof(CPUARMState, cp15.nsacr) },
>      { .name = "MVBAR", .cp = 15, .opc1 = 0, .crn = 12, .crm = 0, .opc2 = 1,
> -      .access = PL3_RW, .writefn = vbar_write, .resetvalue = 0,
> +      .access = PL1_RW, .accessfn = access_trap_aa32s_el1,
> +      .writefn = vbar_write, .resetvalue = 0,
>        .fieldoffset = offsetof(CPUARMState, cp15.mvbar) },
>      { .name = "SCTLR_EL3", .state = ARM_CP_STATE_AA64,
>        .type = ARM_CP_ALIAS, /* reset handled by AArch32 view */
> -- 
> 1.9.1
>