From: Peter Maydell <>

It doesn't make sense to read the value of MDCR_EL2 on a non-A-profile
CPU, and in fact if you try to do it we will assert:

#6  0x00007ffff4b95e96 in __GI___assert_fail
    (assertion=0x5555565a8c70 "!arm_feature(env, ARM_FEATURE_M)", 
file=0x5555565a6e5c "../../target/arm/helper.c", line=12600, 
function=0x5555565a9560 <__PRETTY_FUNCTION__.0> "arm_security_space_below_el3") 
at ./assert/assert.c:101
#7  0x0000555555ebf412 in arm_security_space_below_el3 (env=0x555557bc8190) at 
#8  0x0000555555ea6f89 in arm_is_el2_enabled (env=0x555557bc8190) at 
#9  0x0000555555ea942f in arm_mdcr_el2_eff (env=0x555557bc8190) at 

We might call pmu_counter_enabled() on an M-profile CPU (for example
from the migration pre/post hooks in machine.c); this should always
return false because these CPUs don't set ARM_FEATURE_PMU.

Avoid the assertion by not calling arm_mdcr_el2_eff() before we
have done the early return for "PMU not present".

This fixes an assertion failure if you try to do a loadvm or
savevm for an M-profile board.

Signed-off-by: Peter Maydell <>
Reviewed-by: Philippe Mathieu-Daudé <>
Reviewed-by: Richard Henderson <>
(cherry picked from commit ac1d88e9e7ca0bed83e91e07ce6d0597f10cc77d)
Signed-off-by: Michael Tokarev <>

diff --git a/target/arm/helper.c b/target/arm/helper.c
index 343acfab3a..2e284e048c 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -1125,13 +1125,21 @@ static bool pmu_counter_enabled(CPUARMState *env, 
uint8_t counter)
     bool enabled, prohibited = false, filtered;
     bool secure = arm_is_secure(env);
     int el = arm_current_el(env);
-    uint64_t mdcr_el2 = arm_mdcr_el2_eff(env);
-    uint8_t hpmn = mdcr_el2 & MDCR_HPMN;
+    uint64_t mdcr_el2;
+    uint8_t hpmn;
+    /*
+     * We might be called for M-profile cores where MDCR_EL2 doesn't
+     * exist and arm_mdcr_el2_eff() will assert, so this early-exit check
+     * must be before we read that value.
+     */
     if (!arm_feature(env, ARM_FEATURE_PMU)) {
         return false;
+    mdcr_el2 = arm_mdcr_el2_eff(env);
+    hpmn = mdcr_el2 & MDCR_HPMN;
     if (!arm_feature(env, ARM_FEATURE_EL2) ||
             (counter < hpmn || counter == 31)) {
         e = env->cp15.c9_pmcr & PMCRE;

Reply via email to