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| author | Peter Maydell <peter.maydell@linaro.org> | 2024-02-08 15:33:46 +0000 |
|---|---|---|
| committer | Peter Maydell <peter.maydell@linaro.org> | 2024-02-15 11:36:42 +0000 |
| commit | ac1d88e9e7ca0bed83e91e07ce6d0597f10cc77d (patch) | |
| tree | 21857c771bf28fc4668609df810f0881b258137a | |
| parent | bf25d7815b0c0d58c43c3301d8debf1c75727547 (diff) | |
| download | qemu-ac1d88e9e7ca0bed83e91e07ce6d0597f10cc77d.zip qemu-ac1d88e9e7ca0bed83e91e07ce6d0597f10cc77d.tar.gz qemu-ac1d88e9e7ca0bed83e91e07ce6d0597f10cc77d.tar.bz2 | |
target/arm: Don't get MDCR_EL2 in pmu_counter_enabled() before checking ARM_FEATURE_PMU
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 ../../target/arm/helper.c:12600
#8 0x0000555555ea6f89 in arm_is_el2_enabled (env=0x555557bc8190) at ../../target/arm/cpu.h:2595
#9 0x0000555555ea942f in arm_mdcr_el2_eff (env=0x555557bc8190) at ../../target/arm/internals.h:1512
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.
Cc: qemu-stable@nongnu.org
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2155
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20240208153346.970021-1-peter.maydell@linaro.org
| -rw-r--r-- | target/arm/helper.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/target/arm/helper.c b/target/arm/helper.c index 8c1ff16..7c531ee 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -1187,13 +1187,21 @@ 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; |