On Tue, Mar 17, 2015 at 06:02:41PM +0000, Andre Przywara wrote: > Hej, > > On 14/03/15 14:30, Christoffer Dall wrote: > > On Fri, Mar 13, 2015 at 04:10:09PM +0000, Andre Przywara wrote: > >> Using the framework provided by the recent vgic.c changes we register > >> a kvm_io_bus device when initializing the virtual GICv2. > >> > >> Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx> > >> --- > >> include/kvm/arm_vgic.h | 1 + > >> virt/kvm/arm/vgic-v2-emul.c | 13 +++++++++---- > >> virt/kvm/arm/vgic.c | 16 ++++++++++++++++ > >> 3 files changed, 26 insertions(+), 4 deletions(-) > >> > >> diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h > >> index 4bfc6a3..74a4ac4 100644 > >> --- a/include/kvm/arm_vgic.h > >> +++ b/include/kvm/arm_vgic.h > >> @@ -245,6 +245,7 @@ struct vgic_dist { > >> unsigned long *irq_pending_on_cpu; > >> > >> struct vgic_vm_ops vm_ops; > >> + struct vgic_io_device dist_iodev; > >> }; > >> > >> struct vgic_v2_cpu_if { > >> diff --git a/virt/kvm/arm/vgic-v2-emul.c b/virt/kvm/arm/vgic-v2-emul.c > >> index 0defac6..6f685c9 100644 > >> --- a/virt/kvm/arm/vgic-v2-emul.c > >> +++ b/virt/kvm/arm/vgic-v2-emul.c > >> @@ -490,6 +490,7 @@ static bool vgic_v2_queue_sgi(struct kvm_vcpu *vcpu, int irq) > >> static int vgic_v2_map_resources(struct kvm *kvm, > >> const struct vgic_params *params) > >> { > >> + struct vgic_dist *dist = &kvm->arch.vgic; > >> int ret = 0; > >> > >> if (!irqchip_in_kernel(kvm)) > >> @@ -500,13 +501,17 @@ static int vgic_v2_map_resources(struct kvm *kvm, > >> if (vgic_ready(kvm)) > >> goto out; > >> > >> - if (IS_VGIC_ADDR_UNDEF(kvm->arch.vgic.vgic_dist_base) || > >> - IS_VGIC_ADDR_UNDEF(kvm->arch.vgic.vgic_cpu_base)) { > >> + if (IS_VGIC_ADDR_UNDEF(dist->vgic_dist_base) || > >> + IS_VGIC_ADDR_UNDEF(dist->vgic_cpu_base)) { > >> kvm_err("Need to set vgic cpu and dist addresses first\n"); > >> ret = -ENXIO; > >> goto out; > >> } > >> > >> + vgic_register_kvm_io_dev(kvm, dist->vgic_dist_base, > >> + KVM_VGIC_V2_DIST_SIZE, > >> + vgic_dist_ranges, -1, &dist->dist_iodev); > >> + > >> /* > >> * Initialize the vgic if this hasn't already been done on demand by > >> * accessing the vgic state from userspace. > >> @@ -517,7 +522,7 @@ static int vgic_v2_map_resources(struct kvm *kvm, > >> goto out; > >> } > >> > >> - ret = kvm_phys_addr_ioremap(kvm, kvm->arch.vgic.vgic_cpu_base, > >> + ret = kvm_phys_addr_ioremap(kvm, dist->vgic_cpu_base, > >> params->vcpu_base, KVM_VGIC_V2_CPU_SIZE, > >> true); > >> if (ret) { > >> @@ -525,7 +530,7 @@ static int vgic_v2_map_resources(struct kvm *kvm, > >> goto out; > >> } > >> > >> - kvm->arch.vgic.ready = true; > >> + dist->ready = true; > >> out: > >> if (ret) > >> kvm_vgic_destroy(kvm); > >> diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c > >> index 71389b8..b1dd717 100644 > >> --- a/virt/kvm/arm/vgic.c > >> +++ b/virt/kvm/arm/vgic.c > >> @@ -908,6 +908,20 @@ int vgic_register_kvm_io_dev(struct kvm *kvm, gpa_t base, int len, > >> return 0; > >> } > >> > >> +static void vgic_unregister_kvm_io_dev(struct kvm *kvm) > >> +{ > >> + struct vgic_dist *dist = &kvm->arch.vgic; > >> + > >> + if (!dist || !kvm->buses[KVM_MMIO_BUS]) > >> + return; > >> + > >> + mutex_lock(&kvm->slots_lock); > >> + if (dist->dist_iodev.dev.ops) > >> + kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS, > >> + &dist->dist_iodev.dev); > > > > why are we only unregisttering the iodev when we have ops? > > Because vgic_unregister_kvm_io_dev() is called by kvm_vgic_destroy(), > which we call on some occasions during vgic_init() when we encounter an > error. There is quite a window of cases where the kvm_io_bus devices > haven't been registered yet, so we shouldn't try to unregister them at > this place. Using the .ops parameter seemed like an elegant way to > detect this case. > Does that make sense? Or have I missed something? > That's ok, but it derserves a comment explaining this. -Christoffer -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html