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authorPeter Maydell <peter.maydell@linaro.org>2017-01-09 14:30:36 +0000
committerPeter Maydell <peter.maydell@linaro.org>2017-01-09 15:27:25 +0000
commitc518f892452e880f36983cb89f0b4e10c6229a7c (patch)
tree4cbe7f0852d7f48651e52a95e870d1cc740e1e07
parent2ed59eccfbc5ae6606d4780ef32a95199f4f14bb (diff)
downloadqemu-arm-c518f892452e880f36983cb89f0b4e10c6229a7c.tar.gz
target/arm/psci.c: If EL2 implemented, start CPUs in EL2
The PSCI spec states that a CPU_ON call should cause the new CPU to be started in the highest implemented Non-secure exception level. We were incorrectly starting it at the exception level of the caller, which happens to be correct if EL2 is not implemented. Implement the correct logic as described in the PSCI 1.0 spec section 6.4: * if EL2 exists and SCR_EL3.HCE is set: start in EL2 * otherwise start in EL1 Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
-rw-r--r--target/arm/psci.c25
1 files changed, 18 insertions, 7 deletions
diff --git a/target/arm/psci.c b/target/arm/psci.c
index 14316eb0ae..64bf82eea1 100644
--- a/target/arm/psci.c
+++ b/target/arm/psci.c
@@ -148,17 +148,28 @@ void arm_handle_psci_call(ARMCPU *cpu)
case QEMU_PSCI_0_1_FN_CPU_ON:
case QEMU_PSCI_0_2_FN_CPU_ON:
case QEMU_PSCI_0_2_FN64_CPU_ON:
+ {
+ /* The PSCI spec mandates that newly brought up CPUs start
+ * in the highest exception level which exists and is enabled
+ * on the calling CPU. Since the QEMU PSCI implementation is
+ * acting as a "fake EL3" or "fake EL2" firmware, this for us
+ * means that we want to start at the highest NS exception level
+ * that we are providing to the guest.
+ * The execution mode should be that which is currently in use
+ * by the same exception level on the calling CPU.
+ * The CPU should be started with the context_id value
+ * in x0 (if AArch64) or r0 (if AArch32).
+ */
+ int target_el = arm_feature(env, ARM_FEATURE_EL2) ? 2 : 1;
+ bool target_aarch64 = arm_el_is_aa64(env, target_el);
+
mpidr = param[1];
entry = param[2];
context_id = param[3];
- /*
- * The PSCI spec mandates that newly brought up CPUs enter the
- * exception level of the caller in the same execution mode as
- * the caller, with context_id in x0/r0, respectively.
- */
- ret = arm_set_cpu_on(mpidr, entry, context_id, arm_current_el(env),
- is_a64(env));
+ ret = arm_set_cpu_on(mpidr, entry, context_id,
+ target_el, target_aarch64);
break;
+ }
case QEMU_PSCI_0_1_FN_CPU_OFF:
case QEMU_PSCI_0_2_FN_CPU_OFF:
goto cpu_off;