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-rw-r--r--target/arm/op_helper.c54
1 files changed, 46 insertions, 8 deletions
diff --git a/target/arm/op_helper.c b/target/arm/op_helper.c
index eb6fb82fb8..0d6e89e474 100644
--- a/target/arm/op_helper.c
+++ b/target/arm/op_helper.c
@@ -939,7 +939,38 @@ void HELPER(pre_smc)(CPUARMState *env, uint32_t syndrome)
ARMCPU *cpu = arm_env_get_cpu(env);
int cur_el = arm_current_el(env);
bool secure = arm_is_secure(env);
- bool smd = env->cp15.scr_el3 & SCR_SMD;
+ bool smd_flag = env->cp15.scr_el3 & SCR_SMD;
+
+ /*
+ * SMC behaviour is summarized in the following table.
+ * This helper handles the "Trap to EL2" and "Undef insn" cases.
+ * The "Trap to EL3" and "PSCI call" cases are handled in the exception
+ * helper.
+ *
+ * -> ARM_FEATURE_EL3 and !SMD
+ * HCR_TSC && NS EL1 !HCR_TSC || !NS EL1
+ *
+ * Conduit SMC, valid call Trap to EL2 PSCI Call
+ * Conduit SMC, inval call Trap to EL2 Trap to EL3
+ * Conduit not SMC Trap to EL2 Trap to EL3
+ *
+ *
+ * -> ARM_FEATURE_EL3 and SMD
+ * HCR_TSC && NS EL1 !HCR_TSC || !NS EL1
+ *
+ * Conduit SMC, valid call Trap to EL2 PSCI Call
+ * Conduit SMC, inval call Trap to EL2 Undef insn
+ * Conduit not SMC Trap to EL2 Undef insn
+ *
+ *
+ * -> !ARM_FEATURE_EL3
+ * HCR_TSC && NS EL1 !HCR_TSC || !NS EL1
+ *
+ * Conduit SMC, valid call Trap to EL2 PSCI Call
+ * Conduit SMC, inval call Trap to EL2 Undef insn
+ * Conduit not SMC Undef insn Undef insn
+ */
+
/* On ARMv8 with EL3 AArch64, SMD applies to both S and NS state.
* On ARMv8 with EL3 AArch32, or ARMv7 with the Virtualization
* extensions, SMD only applies to NS state.
@@ -947,7 +978,8 @@ void HELPER(pre_smc)(CPUARMState *env, uint32_t syndrome)
* doesn't exist, but we forbid the guest to set it to 1 in scr_write(),
* so we need not special case this here.
*/
- bool undef = arm_feature(env, ARM_FEATURE_AARCH64) ? smd : smd && !secure;
+ bool smd = arm_feature(env, ARM_FEATURE_AARCH64) ? smd_flag
+ : smd_flag && !secure;
if (!arm_feature(env, ARM_FEATURE_EL3) &&
cpu->psci_conduit != QEMU_PSCI_CONDUIT_SMC) {
@@ -957,21 +989,27 @@ void HELPER(pre_smc)(CPUARMState *env, uint32_t syndrome)
* to forbid its EL1 from making PSCI calls into QEMU's
* "firmware" via HCR.TSC, so for these purposes treat
* PSCI-via-SMC as implying an EL3.
+ * This handles the very last line of the previous table.
*/
- undef = true;
- } else if (!secure && cur_el == 1 && (env->cp15.hcr_el2 & HCR_TSC)) {
+ raise_exception(env, EXCP_UDEF, syn_uncategorized(),
+ exception_target_el(env));
+ }
+
+ if (!secure && cur_el == 1 && (env->cp15.hcr_el2 & HCR_TSC)) {
/* In NS EL1, HCR controlled routing to EL2 has priority over SMD.
* We also want an EL2 guest to be able to forbid its EL1 from
* making PSCI calls into QEMU's "firmware" via HCR.TSC.
+ * This handles all the "Trap to EL2" cases of the previous table.
*/
raise_exception(env, EXCP_HYP_TRAP, syndrome, 2);
}
- /* If PSCI is enabled and this looks like a valid PSCI call then
- * suppress the UNDEF -- we'll catch the SMC exception and
- * implement the PSCI call behaviour there.
+ /* Catch the two remaining "Undef insn" cases of the previous table:
+ * - PSCI conduit is SMC but we don't have a valid PCSI call,
+ * - We don't have EL3 or SMD is set.
*/
- if (undef && !arm_is_psci_call(cpu, EXCP_SMC)) {
+ if (!arm_is_psci_call(cpu, EXCP_SMC) &&
+ (smd || !arm_feature(env, ARM_FEATURE_EL3))) {
raise_exception(env, EXCP_UDEF, syn_uncategorized(),
exception_target_el(env));
}