From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Morse Subject: [PATCH v2] arm64: KVM: Register CPU notifiers when the kernel runs at HYP Date: Wed, 30 Mar 2016 18:33:04 +0100 Message-ID: <1459359184-15601-1-git-send-email-james.morse@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 1E1DC41390 for ; Wed, 30 Mar 2016 13:33:45 -0400 (EDT) Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id JjzkkOi1W0K0 for ; Wed, 30 Mar 2016 13:33:43 -0400 (EDT) Received: from foss.arm.com (foss.arm.com [217.140.101.70]) by mm01.cs.columbia.edu (Postfix) with ESMTP id D9FA2412ED for ; Wed, 30 Mar 2016 13:33:43 -0400 (EDT) List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu To: kvmarm@lists.cs.columbia.edu Cc: Marc Zyngier , linux-arm-kernel@lists.infradead.org List-Id: kvmarm@lists.cs.columbia.edu 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. Fixes: 1e947bad0b6 ("arm64: KVM: Skip HYP setup when already running in HYP") Signed-off-by: James Morse --- Change since v1: * Moved common re-init code to cpu_hyp_reinit(). 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; } @@ -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); -- 2.8.0.rc3