Edgar E. Iglesias <edgar.igles...@gmail.com> writes:
> From: "Edgar E. Iglesias" <edgar.igles...@xilinx.com>
>
> Implement the inputsize > pamax check for Stage 2 translations.
> We have multiple choices for how to respond to errors and
> choose to fault.
>
> Signed-off-by: Edgar E. Iglesias <edgar.igles...@xilinx.com>
> ---
> target-arm/helper.c | 16 ++++++++++++----
> 1 file changed, 12 insertions(+), 4 deletions(-)
>
> diff --git a/target-arm/helper.c b/target-arm/helper.c
> index 4abeb4d..9a7ff5e 100644
> --- a/target-arm/helper.c
> +++ b/target-arm/helper.c
> @@ -6808,7 +6808,7 @@ static bool get_phys_addr_lpae(CPUARMState *env,
> target_ulong address,
> */
> int startlevel = extract32(tcr->raw_tcr, 6, 2);
> unsigned int pamax = arm_pamax(cpu);
> - bool ok;
> + bool ok = true;
>
> if (va_size == 32 || stride == 9) {
> /* AArch32 or 4KB pages */
> @@ -6818,9 +6818,17 @@ static bool get_phys_addr_lpae(CPUARMState *env,
> target_ulong address,
> level = 3 - startlevel;
> }
>
> - /* Check that the starting level is valid. */
> - ok = check_s2_startlevel(cpu, va_size == 64, level,
> - inputsize, stride, pamax);
> + if (va_size == 64 &&
> + inputsize > pamax &&
> + (arm_el_is_aa64(env, 1) || inputsize > 40)) {
If va_size == 64 doesn't that imply arm_el_is_aa64(env, 1)? Looking
further up the function it seems that is what sets va_size in the first
place. I think that makes the inputsize > 40 check redundant.
> + /* We have multiple choices but choose to fault. */
> + ok = false;
> + }
> + if (ok) {
> + /* Check that the starting level is valid. */
> + ok = check_s2_startlevel(cpu, va_size == 64, level,
> + inputsize, stride, pamax);
> + }
> if (!ok) {
> /* AArch64 reports these as level 0 faults.
> * AArch32 reports these as level 1 faults.
I'm not a fan of the ok = true / ok = false / ok =
check_s2_start_level() / if (!ok) ping-pong here as it is hard to
follow. I'm not sure how you could make it cleaner to follow though.
Maybe something like:
/* For stage 2 translations the starting level is specified by the
* VTCR_EL2.SL0 field (whose interpretation depends on the page size)
*/
int startlevel = extract32(tcr->raw_tcr, 6, 2);
unsigned int pamax = arm_pamax(cpu);
bool is_aarch64_regime = (va_size == 64);
bool ok;
if (va_size == 32 || stride == 9) {
/* AArch32 or 4KB pages */
level = 2 - startlevel;
} else {
/* 16KB or 64KB pages */
level = 3 - startlevel;
}
if (is_aarch64_regime &&
inputsize > pamax) {
/* We have multiple choices but choose to fault. */
ok = false;
} else {
/* Check that the starting level is valid. */
ok = check_s2_startlevel(cpu, is_aarch64_regime, level,
inputsize, stride, pamax);
}
if (!ok) {
/* AArch64 reports these as level 0 faults.
* AArch32 reports these as level 1 faults.
*/
level = is_aarch64_regime ? 0 : 1;
fault_type = translation_fault;
goto do_fault;
}
But I'm wondering if it just makes more sense to push the:
is_aarch64_regime && inputsize > pamax
Check into check_s2_startlevel? Then you could just have a simple call
which succeeds or falls through to a fault?
/* Check that the starting level is valid. */
if (!check_s2_startlevel(cpu, is_aarch64_regime, level,
inputsize, stride, pamax) ){
/* AArch64 reports these as level 0 faults.
* AArch32 reports these as level 1 faults.
*/
level = is_aarch64_regime ? 0 : 1;
fault_type = translation_fault;
goto do_fault;
}
--
Alex Bennée
