[PATCH] target/arm: Only evaluate SCR_EL3.PIEN if ARM_FEATURE_EL3 is present

[Oliver Upton <oupton@kernel.org>]

Running KVM with (as of writing, out-of-tree) support for FEAT_S2PIE
on -cpu max gets stuck in an infinite loop of stage-2 permission faults
due to the PTW incorrectly using an effective value of 0 for S2PIR_EL2.

Similar to how S1PIE is handled, only use the IMPLEMENTATION SPECIFIC
value of 0 for S2PIR_EL2 if EL3 is implemented and PIEN=0.

Fixes: a811c5dafb ("target/arm: Implement get_S2prot_indirect")
Signed-off-by: Oliver Upton <oupton@kernel.org>
---
 target/arm/ptw.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/target/arm/ptw.c b/target/arm/ptw.c
index 1470de3010..4a7aeb140c 100644
--- a/target/arm/ptw.c
+++ b/target/arm/ptw.c
@@ -1414,9 +1414,13 @@ static int get_S2prot_indirect(CPUARMState *env, GetPhysAddrResult *result,
                   PAGE_READ | PAGE_WRITE },
     };
 
-    uint64_t pir = (env->cp15.scr_el3 & SCR_PIEN ? env->cp15.s2pir_el2 : 0);
-    int s2pi = extract64(pir, pi_index * 4, 4);
+    uint64_t pir = env->cp15.s2pir_el2;
+    int s2pi;
 
+    if (arm_feature(env, ARM_FEATURE_EL3) && !(env->cp15.scr_el3 & SCR_PIEN))
+	pir = 0;
+
+    s2pi = extract64(pir, pi_index * 4, 4);
     result->f.prot = perm_table[s2pi][2];
     return perm_table[s2pi][s1_is_el0];
 }

base-commit: 8f1d3b586f1265023f75ea9c227c35d463321aef
-- 
2.47.3