From: Philippe Mathieu-Daudé <philmd@linaro.org>
Date: Tue, 28 Oct 2025 05:42:05 +0000 (+0100)
Subject: target/arm/hvf/hvf: Document $pc adjustment in HVF & SMC
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=31e1b9823056f4d1d95b5a76029411954aaaf2af;p=thirdparty%2Fqemu.git

target/arm/hvf/hvf: Document $pc adjustment in HVF & SMC

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---

diff --git a/target/arm/hvf/hvf.c b/target/arm/hvf/hvf.c
index f31b6e54ee..805fe75e6b 100644
--- a/target/arm/hvf/hvf.c
+++ b/target/arm/hvf/hvf.c
@@ -1936,6 +1936,7 @@ static int hvf_handle_exception(CPUState *cpu, hv_vcpu_exit_exception_t *excp)
     case EC_AA64_HVC:
         cpu_synchronize_state(cpu);
         if (arm_is_psci_call(arm_cpu, EXCP_HVC)) {
+            /* Do NOT advance $pc for HVC */
             if (!hvf_handle_psci_call(cpu)) {
                 trace_hvf_unknown_hvc(env->pc, env->xregs[0]);
                 /* SMCCC 1.3 section 5.2 says every unknown SMCCC call returns -1 */
@@ -1949,6 +1950,7 @@ static int hvf_handle_exception(CPUState *cpu, hv_vcpu_exit_exception_t *excp)
     case EC_AA64_SMC:
         cpu_synchronize_state(cpu);
         if (arm_is_psci_call(arm_cpu, EXCP_SMC)) {
+            /* Secure Monitor Call exception, we need to advance $pc */
             advance_pc = true;
 
             if (!hvf_handle_psci_call(cpu)) {