Commit 733c758e authored by Oliver Upton's avatar Oliver Upton
Browse files

KVM: arm64: Rephrase percpu enable/disable tracking in terms of hyp 



kvm_arm_hardware_enabled is rather misleading, since it doesn't track
the state of all hardware resources needed for running a VM. What it
actually tracks is whether or not the hyp cpu context has been
initialized.

Since we're now at the point where vgic + timer irq management has
been separated from kvm_arm_hardware_enabled, rephrase it (and the
associated helpers) to make it clear what state is being tracked.

Acked-by: default avatarMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230719231855.262973-1-oliver.upton@linux.dev


Signed-off-by: default avatarOliver Upton <oliver.upton@linux.dev>
parent c718ca0e

arch/arm64/kvm/arm.c

+23 −23
Original line number Diff line number Diff line
@@ -55,7 +55,7 @@ DECLARE_KVM_NVHE_PER_CPU(struct kvm_cpu_context, kvm_hyp_ctxt); 


static bool vgic_present, kvm_arm_initialised;



static DEFINE_PER_CPU(unsigned char, kvm_arm_hardware_enabled);

static DEFINE_PER_CPU(unsigned char, kvm_hyp_initialized);

DEFINE_STATIC_KEY_FALSE(userspace_irqchip_in_use);



bool is_kvm_arm_initialised(void)
@@ -1864,11 +1864,19 @@ static void cpu_hyp_reinit(void) 
	cpu_hyp_init_features();

}



static void _kvm_arch_hardware_enable(void *discard)

static void cpu_hyp_init(void *discard)

{

	if (!__this_cpu_read(kvm_arm_hardware_enabled)) {

	if (!__this_cpu_read(kvm_hyp_initialized)) {

		cpu_hyp_reinit();

		__this_cpu_write(kvm_arm_hardware_enabled, 1);

		__this_cpu_write(kvm_hyp_initialized, 1);

	}

}



static void cpu_hyp_uninit(void *discard)

{

	if (__this_cpu_read(kvm_hyp_initialized)) {

		cpu_hyp_reset();

		__this_cpu_write(kvm_hyp_initialized, 0);

	}

}
@@ -1882,7 +1890,7 @@ int kvm_arch_hardware_enable(void) 
	 */

	preempt_disable();



	_kvm_arch_hardware_enable(NULL);

	cpu_hyp_init(NULL);



	kvm_vgic_cpu_up();

	kvm_timer_cpu_up();
@@ -1892,21 +1900,13 @@ int kvm_arch_hardware_enable(void) 
	return 0;

}



static void _kvm_arch_hardware_disable(void *discard)

{

	if (__this_cpu_read(kvm_arm_hardware_enabled)) {

		cpu_hyp_reset();

		__this_cpu_write(kvm_arm_hardware_enabled, 0);

	}

}



void kvm_arch_hardware_disable(void)

{

	kvm_timer_cpu_down();

	kvm_vgic_cpu_down();



	if (!is_protected_kvm_enabled())

		_kvm_arch_hardware_disable(NULL);

		cpu_hyp_uninit(NULL);

}



#ifdef CONFIG_CPU_PM
@@ -1915,16 +1915,16 @@ static int hyp_init_cpu_pm_notifier(struct notifier_block *self, 
				    void *v)

{

	/*

	 * kvm_arm_hardware_enabled is left with its old value over

	 * kvm_hyp_initialized is left with its old value over

	 * PM_ENTER->PM_EXIT. It is used to indicate PM_EXIT should

	 * re-enable hyp.

	 */

	switch (cmd) {

	case CPU_PM_ENTER:

		if (__this_cpu_read(kvm_arm_hardware_enabled))

		if (__this_cpu_read(kvm_hyp_initialized))

			/*

			 * don't update kvm_arm_hardware_enabled here

			 * so that the hardware will be re-enabled

			 * don't update kvm_hyp_initialized here

			 * so that the hyp will be re-enabled

			 * when we resume. See below.

			 */

			cpu_hyp_reset();
@@ -1932,8 +1932,8 @@ static int hyp_init_cpu_pm_notifier(struct notifier_block *self, 
		return NOTIFY_OK;

	case CPU_PM_ENTER_FAILED:

	case CPU_PM_EXIT:

		if (__this_cpu_read(kvm_arm_hardware_enabled))

			/* The hardware was enabled before suspend. */

		if (__this_cpu_read(kvm_hyp_initialized))

			/* The hyp was enabled before suspend. */

			cpu_hyp_reinit();



		return NOTIFY_OK;
@@ -2014,7 +2014,7 @@ static int __init init_subsystems(void) 
	/*

	 * Enable hardware so that subsystem initialisation can access EL2.

	 */

	on_each_cpu(_kvm_arch_hardware_enable, NULL, 1);

	on_each_cpu(cpu_hyp_init, NULL, 1);



	/*

	 * Register CPU lower-power notifier
@@ -2052,7 +2052,7 @@ static int __init init_subsystems(void) 
		hyp_cpu_pm_exit();



	if (err || !is_protected_kvm_enabled())

		on_each_cpu(_kvm_arch_hardware_disable, NULL, 1);

		on_each_cpu(cpu_hyp_uninit, NULL, 1);



	return err;

}
@@ -2090,7 +2090,7 @@ static int __init do_pkvm_init(u32 hyp_va_bits) 
	 * The stub hypercalls are now disabled, so set our local flag to

	 * prevent a later re-init attempt in kvm_arch_hardware_enable().

	 */

	__this_cpu_write(kvm_arm_hardware_enabled, 1);

	__this_cpu_write(kvm_hyp_initialized, 1);

	preempt_enable();



	return ret;