* This function finds the right table above and sets the registers on
* the virtual CPU struct to their architecturally defined reset
* values.
+ *
+ * Note: This function can be called from two paths: The KVM_ARM_VCPU_INIT
+ * ioctl or as part of handling a request issued by another VCPU in the PSCI
+ * handling code. In the first case, the VCPU will not be loaded, and in the
+ * second case the VCPU will be loaded. Because this function operates purely
+ * on the memory-backed valus of system registers, we want to do a full put if
+ * we were loaded (handling a request) and load the values back at the end of
+ * the function. Otherwise we leave the state alone. In both cases, we
+ * disable preemption around the vcpu reset as we would otherwise race with
+ * preempt notifiers which also call put/load.
*/
int kvm_reset_vcpu(struct kvm_vcpu *vcpu)
{
const struct kvm_regs *cpu_reset;
+ int ret = -EINVAL;
+ bool loaded;
+
+ preempt_disable();
+ loaded = (vcpu->cpu != -1);
+ if (loaded)
+ kvm_arch_vcpu_put(vcpu);
switch (vcpu->arch.target) {
default:
if (test_bit(KVM_ARM_VCPU_EL1_32BIT, vcpu->arch.features)) {
if (!cpu_has_32bit_el1())
- return -EINVAL;
+ goto out;
cpu_reset = &default_regs_reset32;
} else {
cpu_reset = &default_regs_reset;
vcpu->arch.workaround_flags |= VCPU_WORKAROUND_2_FLAG;
/* Reset timer */
- return kvm_timer_vcpu_reset(vcpu);
+ ret = kvm_timer_vcpu_reset(vcpu);
+out:
+ if (loaded)
+ kvm_arch_vcpu_load(vcpu, smp_processor_id());
+ preempt_enable();
+ return ret;
}
void kvm_set_ipa_limit(void)