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Commit 5f5560b1 authored by James Morse's avatar James Morse Committed by Christoffer Dall
Browse files

arm64: KVM: Register CPU notifiers when the kernel runs at HYP 



When the kernel is running at EL2, it doesn't need init_hyp_mode() to
configure page tables for HYP. This function also registers the CPU
hotplug and lower power notifiers that cause HYP to be re-initialised
after the CPU has been reset.

To avoid losing the register state that controls stage2 translation, move
the registering of these notifiers into init_subsystems(), and add a
is_kernel_in_hyp_mode() path to each callback.

Acked-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Acked-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
Fixes: 1e947bad ("arm64: KVM: Skip HYP setup when already running in HYP")
Signed-off-by: default avatarJames Morse <james.morse@arm.com>
Signed-off-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
parent cb678d60

arch/arm/kvm/arm.c

+33 −19
Original line number Diff line number Diff line
@@ -1061,15 +1061,27 @@ static void cpu_init_hyp_mode(void *dummy) 
	kvm_arm_init_debug();

}



static void cpu_hyp_reinit(void)

{

	if (is_kernel_in_hyp_mode()) {

		/*

		 * cpu_init_stage2() is safe to call even if the PM

		 * event was cancelled before the CPU was reset.

		 */

		cpu_init_stage2(NULL);

	} else {

		if (__hyp_get_vectors() == hyp_default_vectors)

			cpu_init_hyp_mode(NULL);

	}

}



static int hyp_init_cpu_notify(struct notifier_block *self,

			       unsigned long action, void *cpu)

{

	switch (action) {

	case CPU_STARTING:

	case CPU_STARTING_FROZEN:

		if (__hyp_get_vectors() == hyp_default_vectors)

			cpu_init_hyp_mode(NULL);

		break;

		cpu_hyp_reinit();

	}



	return NOTIFY_OK;
@@ -1084,9 +1096,8 @@ static int hyp_init_cpu_pm_notifier(struct notifier_block *self, 
				    unsigned long cmd,

				    void *v)

{

	if (cmd == CPU_PM_EXIT &&

	    __hyp_get_vectors() == hyp_default_vectors) {

		cpu_init_hyp_mode(NULL);

	if (cmd == CPU_PM_EXIT) {

		cpu_hyp_reinit();

		return NOTIFY_OK;

	}
@@ -1127,6 +1138,22 @@ static int init_subsystems(void) 
{

	int err;



	/*

	 * Register CPU Hotplug notifier

	 */

	cpu_notifier_register_begin();

	err = __register_cpu_notifier(&hyp_init_cpu_nb);

	cpu_notifier_register_done();

	if (err) {

		kvm_err("Cannot register KVM init CPU notifier (%d)\n", err);

		return err;

	}



	/*

	 * Register CPU lower-power notifier

	 */

	hyp_cpu_pm_init();



	/*

	 * Init HYP view of VGIC

	 */
@@ -1270,19 +1297,6 @@ static int init_hyp_mode(void) 
	free_boot_hyp_pgd();

#endif



	cpu_notifier_register_begin();



	err = __register_cpu_notifier(&hyp_init_cpu_nb);



	cpu_notifier_register_done();



	if (err) {

		kvm_err("Cannot register HYP init CPU notifier (%d)\n", err);

		goto out_err;

	}



	hyp_cpu_pm_init();



	/* set size of VMID supported by CPU */

	kvm_vmid_bits = kvm_get_vmid_bits();

	kvm_info("%d-bit VMID\n", kvm_vmid_bits);