From 5f5560b1c5f3a80e91c6babb2da34a51943bbdec Mon Sep 17 00:00:00 2001 From: James Morse Date: Wed, 30 Mar 2016 18:33:04 +0100 Subject: [PATCH] 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: Marc Zyngier Acked-by: Christoffer Dall Fixes: 1e947bad0b6 ("arm64: KVM: Skip HYP setup when already running in HYP") Signed-off-by: James Morse Signed-off-by: Christoffer Dall --- 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 6accd66d26f0..b5384311dec4 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; } @@ -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);