On Mon, Jun 29, 2009 at 12:50:31PM -0300, Marcelo Tosatti wrote: > > diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c > > index 148c52a..1851aec 100644 > > --- a/arch/x86/kvm/i8259.c > > +++ b/arch/x86/kvm/i8259.c > > @@ -548,6 +548,6 @@ struct kvm_pic *kvm_create_pic(struct kvm *kvm) > > * Initialize PIO device > > */ > > kvm_iodevice_init(&s->dev, &picdev_ops); > > - kvm_io_bus_register_dev(&kvm->pio_bus, &s->dev); > > + kvm_io_bus_register_dev(kvm, &kvm->pio_bus, &s->dev); > > return s; > > case KVM_CREATE_PIT2: > create_pit: > mutex_lock(&kvm->lock); > kvm_io_bus_register_dev > down_write(slots_lock); > > But the order is slots_lock -> kvm->lock. > > (you might want to update the comment on top of kvm_main.c to > reflect that).
Good catch. I think it's easiest to replace kvm->lock by slots_lock here as well. Does something like the following make sense? If yes I'll roll it up in the series. Signed-off-by: Michael S. Tsirkin <[email protected]> diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c index 3155ffa..add108b 100644 --- a/arch/x86/kvm/i8254.c +++ b/arch/x86/kvm/i8254.c @@ -585,6 +585,7 @@ static const struct kvm_io_device_ops speaker_dev_ops = { .write = speaker_ioport_write, }; +/* Caller must have writers lock on slots_lock */ struct kvm_pit *kvm_create_pit(struct kvm *kvm, u32 flags) { struct kvm_pit *pit; @@ -623,11 +624,11 @@ struct kvm_pit *kvm_create_pit(struct kvm *kvm, u32 flags) kvm_register_irq_mask_notifier(kvm, 0, &pit->mask_notifier); kvm_iodevice_init(&pit->dev, &pit_dev_ops); - kvm_io_bus_register_dev(kvm, &kvm->pio_bus, &pit->dev); + __kvm_io_bus_register_dev(&kvm->pio_bus, &pit->dev); if (flags & KVM_PIT_SPEAKER_DUMMY) { kvm_iodevice_init(&pit->speaker_dev, &speaker_dev_ops); - kvm_io_bus_register_dev(kvm, &kvm->pio_bus, &pit->speaker_dev); + __kvm_io_bus_register_dev(kvm, &kvm->pio_bus, &pit->speaker_dev); } return pit; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 82e76da..4c171e8 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2115,7 +2115,7 @@ long kvm_arch_vm_ioctl(struct file *filp, sizeof(struct kvm_pit_config))) goto out; create_pit: - mutex_lock(&kvm->lock); + down_write(&kvm->slots_lock); r = -EEXIST; if (kvm->arch.vpit) goto create_pit_unlock; @@ -2124,7 +2124,7 @@ long kvm_arch_vm_ioctl(struct file *filp, if (kvm->arch.vpit) r = 0; create_pit_unlock: - mutex_unlock(&kvm->lock); + up_write(&kvm->slots_lock); break; case KVM_IRQ_LINE_STATUS: case KVM_IRQ_LINE: { diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 2ca0eb5..3f95332 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -64,6 +64,8 @@ int kvm_io_bus_write(struct kvm_io_bus *bus, gpa_t addr, int len, const void *val); int kvm_io_bus_read(struct kvm_io_bus *bus, gpa_t addr, int len, void *val); +void __kvm_io_bus_register_dev(struct kvm_io_bus *bus, + struct kvm_io_device *dev); void kvm_io_bus_register_dev(struct kvm *kvm, struct kvm_io_bus *bus, struct kvm_io_device *dev); diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 3730cc4..728118f 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2509,10 +2509,17 @@ void kvm_io_bus_register_dev(struct kvm *kvm, struct kvm_io_bus *bus, struct kvm_io_device *dev) { down_write(&kvm->slots_lock); + __kvm_io_bus_register_dev(bus, dev); + up_write(&kvm->slots_lock); +} + +/* An unlocked version. Caller must have write lock on slots_lock. */ +void __kvm_io_bus_register_dev(struct kvm_io_bus *bus, + struct kvm_io_device *dev) +{ BUG_ON(bus->dev_count > (NR_IOBUS_DEVS-1)); bus->devs[bus->dev_count++] = dev; - up_write(&kvm->slots_lock); } static struct notifier_block kvm_cpu_notifier = { -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
