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: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230719231855.262973-1-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index d854056..d1cb298 100644 (file)
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -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 @@ out:
                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;