From: James Morse <james.morse@xxxxxxx>
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: Marc Zyngier <marc.zyngier@xxxxxxx>
Acked-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx>
Fixes: 1e947bad0b6 ("arm64: KVM: Skip HYP setup when already running in HYP")
Signed-off-by: James Morse <james.morse@xxxxxxx>
Signed-off-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx>
---
arch/arm/kvm/arm.c | 52 +++++++++++++++++++++++++++++++++-------------------
1 file changed, 33 insertions(+), 19 deletions(-)
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 6accd66..b538431 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -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;
}
@@ -1128,6 +1139,22 @@ 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
*/
err = kvm_vgic_hyp_init();
@@ -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);
--
2.1.2.330.g565301e.dirty
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