target/arm: Implement emulation of nested virtualization

[PATCH 18/35] target/arm: Don't honour PSTATE.PAN when HCR_EL2.{NV, NV1} == {1, 1}

Posted by Peter Maydell 11 months, 2 weeks ago

For FEAT_NV, when HCR_EL2.{NV,NV1} is {1,1} PAN is always disabled
even when the PSTATE.PAN bit is set. Implement this by having
arm_pan_enabled() return false in this situation.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 target/arm/helper.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/target/arm/helper.c b/target/arm/helper.c
index 4b0e46cfaae..28448624c36 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -266,6 +266,9 @@ void init_cpreg_list(ARMCPU *cpu)
 static bool arm_pan_enabled(CPUARMState *env)
 {
     if (is_a64(env)) {
+        if ((arm_hcr_el2_eff(env) & (HCR_NV | HCR_NV1)) == (HCR_NV | HCR_NV1)) {
+            return false;
+        }
         return env->pstate & PSTATE_PAN;
     } else {
         return env->uncached_cpsr & CPSR_PAN;
-- 
2.34.1

Re: [PATCH 18/35] target/arm: Don't honour PSTATE.PAN when HCR_EL2.{NV, NV1} == {1, 1}

Posted by Richard Henderson 11 months ago

On 12/18/23 22:32, Peter Maydell wrote:
> For FEAT_NV, when HCR_EL2.{NV,NV1} is {1,1} PAN is always disabled
> even when the PSTATE.PAN bit is set. Implement this by having
> arm_pan_enabled() return false in this situation.
> 
> Signed-off-by: Peter Maydell<peter.maydell@linaro.org>
> ---
>   target/arm/helper.c | 3 +++
>   1 file changed, 3 insertions(+)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~