!405 kvm: arm64: fix some pvsched bugs

Merge Pull Request from: @yezengruan 
 
kvm: arm64: fix some pvsched bugs

1. Clear kvm_vcpu_arch::pvsched::base on vcpu reset
The guest memory will otherwise be corrupted by KVM if we reboot into
an old guest kernel which is **not** aware of the pvsched feature.

2. Fix boot cpu pvsched init abnormal
The pv_sched_init was called too early in the boot in setup_arch, hence
pvsched_vcpu_state was not initializedfo vcpu 0.

https://gitee.com/openeuler/kernel/issues/I6E2VI?from=project-issue 
 
Link:https://gitee.com/openeuler/kernel/pulls/405 

Reviewed-by: Kevin Zhu <zhukeqian1@huawei.com> 
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> 

arch/arm64/kernel/paravirt.c

@@ -351,3 +351,4 @@ int __init pv_sched_init(void)
 
 	return 0;
 }
+early_initcall(pv_sched_init);

arch/arm64/kernel/setup.c

@@ -407,8 +407,6 @@ void __init __no_sanitize_address setup_arch(char **cmdline_p)
 	smp_init_cpus();
 	smp_build_mpidr_hash();
 
-	pv_sched_init();
-
 	/* Init percpu seeds for random tags after cpus are set up. */
 	kasan_init_tags();
 

arch/arm64/kvm/arm.c

@@ -1140,6 +1140,8 @@ static int kvm_arch_vcpu_ioctl_vcpu_init(struct kvm_vcpu *vcpu,
 	else
 		vcpu->arch.power_off = false;
 
+	kvm_arm_pvsched_vcpu_init(&vcpu->arch);
+
 	return 0;
 }