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

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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@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Fixes: 1e947bad0b ("arm64: KVM: Skip HYP setup when already running in HYP")
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
This commit is contained in:
James Morse 2016-03-30 18:33:04 +01:00 committed by Christoffer Dall
parent cb678d6016
commit 5f5560b1c5
1 changed files with 33 additions and 19 deletions
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52
arch/arm/kvm/arm.c
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@ -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);