[Qemu-devel] [PATCH] arm: Fix SMC reporting to EL2 when QEMU provides PSCI

[Jan Kiszka]

From: Jan Kiszka <address@hidden>

This properly forwards SMC events to EL2 when PSCI is provided by QEMU
itself and, thus, ARM_FEATURE_EL3 is off.

Found and tested with the Jailhouse hypervisor.

Signed-off-by: Jan Kiszka <address@hidden>
---
 target/arm/helper.c    | 2 +-
 target/arm/op_helper.c | 8 ++++----
 target/arm/psci.c      | 6 ++++++
 3 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/target/arm/helper.c b/target/arm/helper.c
index 4f41841ef6..8c3929762c 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -3717,7 +3717,7 @@ static void hcr_write(CPUARMState *env, const 
ARMCPRegInfo *ri, uint64_t value)
 
     if (arm_feature(env, ARM_FEATURE_EL3)) {
         valid_mask &= ~HCR_HCD;
-    } else {
+    } else if (cpu->psci_conduit != QEMU_PSCI_CONDUIT_SMC) {
         valid_mask &= ~HCR_TSC;
     }
 
diff --git a/target/arm/op_helper.c b/target/arm/op_helper.c
index 6a60464ab9..4b0ef6a234 100644
--- a/target/arm/op_helper.c
+++ b/target/arm/op_helper.c
@@ -960,12 +960,12 @@ void HELPER(pre_smc)(CPUARMState *env, uint32_t syndrome)
         return;
     }
 
-    if (!arm_feature(env, ARM_FEATURE_EL3)) {
-        /* If we have no EL3 then SMC always UNDEFs */
-        undef = true;
-    } else if (!secure && cur_el == 1 && (env->cp15.hcr_el2 & HCR_TSC)) {
+    if (!secure && cur_el == 1 && (env->cp15.hcr_el2 & HCR_TSC)) {
         /* In NS EL1, HCR controlled routing to EL2 has priority over SMD. */
         raise_exception(env, EXCP_HYP_TRAP, syndrome, 2);
+    } else if (!arm_feature(env, ARM_FEATURE_EL3)) {
+        /* If we have no EL3 then SMC always UNDEFs */
+        undef = true;
     }
 
     if (undef) {
diff --git a/target/arm/psci.c b/target/arm/psci.c
index fc34b263d3..637987ff46 100644
--- a/target/arm/psci.c
+++ b/target/arm/psci.c
@@ -35,6 +35,8 @@ bool arm_is_psci_call(ARMCPU *cpu, int excp_type)
      */
     CPUARMState *env = &cpu->env;
     uint64_t param = is_a64(env) ? env->xregs[0] : env->regs[0];
+    int cur_el = arm_current_el(env);
+    bool secure = arm_is_secure(env);
 
     switch (excp_type) {
     case EXCP_HVC:
@@ -46,6 +48,10 @@ bool arm_is_psci_call(ARMCPU *cpu, int excp_type)
         if (cpu->psci_conduit != QEMU_PSCI_CONDUIT_SMC) {
             return false;
         }
+        if (!secure && cur_el == 1 && (env->cp15.hcr_el2 & HCR_TSC)) {
+            /* The EL2 will handle this. */
+            return false;
+        }
         break;
     default:
         return false;
-- 
2.12.3