From: Marcelo Tosatti mtosatti@redhat.com
commit 5f02ef741a785678930f3ff0a8b6b2b0ef1bb402 upstream.
blocked_vcpu_on_cpu_lock is taken from hard interrupt context (pi_wakeup_handler), therefore it cannot sleep.
Switch it to a raw spinlock.
Fixes:
[41297.066254] BUG: scheduling while atomic: CPU 0/KVM/635218/0x00010001 [41297.066323] Preemption disabled at: [41297.066324] [<ffffffff902ee47f>] irq_enter_rcu+0xf/0x60 [41297.066339] Call Trace: [41297.066342] <IRQ> [41297.066346] dump_stack_lvl+0x34/0x44 [41297.066353] ? irq_enter_rcu+0xf/0x60 [41297.066356] __schedule_bug.cold+0x7d/0x8b [41297.066361] __schedule+0x439/0x5b0 [41297.066365] ? task_blocks_on_rt_mutex.constprop.0.isra.0+0x1b0/0x440 [41297.066369] schedule_rtlock+0x1e/0x40 [41297.066371] rtlock_slowlock_locked+0xf1/0x260 [41297.066374] rt_spin_lock+0x3b/0x60 [41297.066378] pi_wakeup_handler+0x31/0x90 [kvm_intel] [41297.066388] sysvec_kvm_posted_intr_wakeup_ipi+0x9d/0xd0 [41297.066392] </IRQ> [41297.066392] asm_sysvec_kvm_posted_intr_wakeup_ipi+0x12/0x20 ...
Signed-off-by: Marcelo Tosatti mtosatti@redhat.com Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini pbonzini@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/kvm/vmx/posted_intr.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-)
--- a/arch/x86/kvm/vmx/posted_intr.c +++ b/arch/x86/kvm/vmx/posted_intr.c @@ -15,7 +15,7 @@ * can find which vCPU should be waken up. */ static DEFINE_PER_CPU(struct list_head, blocked_vcpu_on_cpu); -static DEFINE_PER_CPU(spinlock_t, blocked_vcpu_on_cpu_lock); +static DEFINE_PER_CPU(raw_spinlock_t, blocked_vcpu_on_cpu_lock);
static inline struct pi_desc *vcpu_to_pi_desc(struct kvm_vcpu *vcpu) { @@ -121,9 +121,9 @@ static void __pi_post_block(struct kvm_v new.control) != old.control);
if (!WARN_ON_ONCE(vcpu->pre_pcpu == -1)) { - spin_lock(&per_cpu(blocked_vcpu_on_cpu_lock, vcpu->pre_pcpu)); + raw_spin_lock(&per_cpu(blocked_vcpu_on_cpu_lock, vcpu->pre_pcpu)); list_del(&vcpu->blocked_vcpu_list); - spin_unlock(&per_cpu(blocked_vcpu_on_cpu_lock, vcpu->pre_pcpu)); + raw_spin_unlock(&per_cpu(blocked_vcpu_on_cpu_lock, vcpu->pre_pcpu)); vcpu->pre_pcpu = -1; } } @@ -154,11 +154,11 @@ int pi_pre_block(struct kvm_vcpu *vcpu) local_irq_disable(); if (!WARN_ON_ONCE(vcpu->pre_pcpu != -1)) { vcpu->pre_pcpu = vcpu->cpu; - spin_lock(&per_cpu(blocked_vcpu_on_cpu_lock, vcpu->pre_pcpu)); + raw_spin_lock(&per_cpu(blocked_vcpu_on_cpu_lock, vcpu->pre_pcpu)); list_add_tail(&vcpu->blocked_vcpu_list, &per_cpu(blocked_vcpu_on_cpu, vcpu->pre_pcpu)); - spin_unlock(&per_cpu(blocked_vcpu_on_cpu_lock, vcpu->pre_pcpu)); + raw_spin_unlock(&per_cpu(blocked_vcpu_on_cpu_lock, vcpu->pre_pcpu)); }
do { @@ -215,7 +215,7 @@ void pi_wakeup_handler(void) struct kvm_vcpu *vcpu; int cpu = smp_processor_id();
- spin_lock(&per_cpu(blocked_vcpu_on_cpu_lock, cpu)); + raw_spin_lock(&per_cpu(blocked_vcpu_on_cpu_lock, cpu)); list_for_each_entry(vcpu, &per_cpu(blocked_vcpu_on_cpu, cpu), blocked_vcpu_list) { struct pi_desc *pi_desc = vcpu_to_pi_desc(vcpu); @@ -223,13 +223,13 @@ void pi_wakeup_handler(void) if (pi_test_on(pi_desc) == 1) kvm_vcpu_kick(vcpu); } - spin_unlock(&per_cpu(blocked_vcpu_on_cpu_lock, cpu)); + raw_spin_unlock(&per_cpu(blocked_vcpu_on_cpu_lock, cpu)); }
void __init pi_init_cpu(int cpu) { INIT_LIST_HEAD(&per_cpu(blocked_vcpu_on_cpu, cpu)); - spin_lock_init(&per_cpu(blocked_vcpu_on_cpu_lock, cpu)); + raw_spin_lock_init(&per_cpu(blocked_vcpu_on_cpu_lock, cpu)); }
bool pi_has_pending_interrupt(struct kvm_vcpu *vcpu)