From: Wanpeng Li Date: Sun, 25 Mar 2018 04:17:24 +0000 (-0700) Subject: KVM: X86: Fix setup the virt_spin_lock_key before static key get initialized X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=34226b6b70980a8f81fff3c09a2c889f77edeeff;p=openwrt%2Fstaging%2Fblogic.git KVM: X86: Fix setup the virt_spin_lock_key before static key get initialized static_key_disable_cpuslocked(): static key 'virt_spin_lock_key+0x0/0x20' used before call to jump_label_init() WARNING: CPU: 0 PID: 0 at kernel/jump_label.c:161 static_key_disable_cpuslocked+0x61/0x80 RIP: 0010:static_key_disable_cpuslocked+0x61/0x80 Call Trace: static_key_disable+0x16/0x20 start_kernel+0x192/0x4b3 secondary_startup_64+0xa5/0xb0 Qspinlock will be choosed when dedicated pCPUs are available, however, the static virt_spin_lock_key is set in kvm_spinlock_init() before jump_label_init() has been called, which will result in a WARN(). This patch fixes it by delaying the virt_spin_lock_key setup to .smp_prepare_cpus(). Reported-by: Davidlohr Bueso Cc: Paolo Bonzini Cc: Radim Krčmář Cc: Davidlohr Bueso Signed-off-by: Wanpeng Li Fixes: b2798ba0b876 ("KVM: X86: Choose qspinlock when dedicated physical CPUs are available") Signed-off-by: Radim Krčmář --- diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c index 4ccbff63cb86..747c61be0f51 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -454,6 +454,13 @@ static void __init sev_map_percpu_data(void) } #ifdef CONFIG_SMP +static void __init kvm_smp_prepare_cpus(unsigned int max_cpus) +{ + native_smp_prepare_cpus(max_cpus); + if (kvm_para_has_hint(KVM_HINTS_DEDICATED)) + static_branch_disable(&virt_spin_lock_key); +} + static void __init kvm_smp_prepare_boot_cpu(void) { /* @@ -557,6 +564,7 @@ static void __init kvm_guest_init(void) kvm_setup_vsyscall_timeinfo(); #ifdef CONFIG_SMP + smp_ops.smp_prepare_cpus = kvm_smp_prepare_cpus; smp_ops.smp_prepare_boot_cpu = kvm_smp_prepare_boot_cpu; if (cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "x86/kvm:online", kvm_cpu_online, kvm_cpu_down_prepare) < 0) @@ -737,10 +745,8 @@ void __init kvm_spinlock_init(void) if (!kvm_para_has_feature(KVM_FEATURE_PV_UNHALT)) return; - if (kvm_para_has_hint(KVM_HINTS_DEDICATED)) { - static_branch_disable(&virt_spin_lock_key); + if (kvm_para_has_hint(KVM_HINTS_DEDICATED)) return; - } __pv_init_lock_hash(); pv_lock_ops.queued_spin_lock_slowpath = __pv_queued_spin_lock_slowpath;