kvm_ioctl_create_device currently has knowledge of all the device types and their associated ops. This is fairly inflexible when adding support for new in-kernel device emulations, so move what we currently have out into a table, which can support dynamic registration of ops by new drivers for virtual hardware.
I didn't try to port all current drivers over, as it's not always clear which initialisation hook the ops should be registered from. Cc: Gleb Natapov <[email protected]> Cc: Paolo Bonzini <[email protected]> Cc: Marc Zyngier <[email protected]> Cc: Christoffer Dall <[email protected]> Signed-off-by: Will Deacon <[email protected]> --- Hi guys, I've just started writing a virtual IOMMU for the ARM SMMU and figured a registration mechanism for kvm_device_ops would be a nice cleanup for that. Will include/linux/kvm_host.h | 1 + include/uapi/linux/kvm.h | 1 + virt/kvm/kvm_main.c | 65 ++++++++++++++++++++++++++++-------------------- 3 files changed, 40 insertions(+), 27 deletions(-) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index ec4e3bd83d47..b75faaf0d76d 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -1083,6 +1083,7 @@ struct kvm_device_ops { void kvm_device_get(struct kvm_device *dev); void kvm_device_put(struct kvm_device *dev); struct kvm_device *kvm_device_from_filp(struct file *filp); +int kvm_register_device_ops(struct kvm_device_ops *ops, u32 type); extern struct kvm_device_ops kvm_mpic_ops; extern struct kvm_device_ops kvm_xics_ops; diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index e11d8f170a62..3b368166286f 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -949,6 +949,7 @@ struct kvm_device_attr { #define KVM_DEV_VFIO_GROUP_DEL 2 #define KVM_DEV_TYPE_ARM_VGIC_V2 5 #define KVM_DEV_TYPE_FLIC 6 +#define KVM_DEV_TYPE_MAX 7 /* * ioctls for VM fds diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 4b6c01b477f9..a0c6cc31a1f6 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2257,44 +2257,55 @@ struct kvm_device *kvm_device_from_filp(struct file *filp) return filp->private_data; } -static int kvm_ioctl_create_device(struct kvm *kvm, - struct kvm_create_device *cd) -{ - struct kvm_device_ops *ops = NULL; - struct kvm_device *dev; - bool test = cd->flags & KVM_CREATE_DEVICE_TEST; - int ret; - - switch (cd->type) { +static struct kvm_device_ops *kvm_device_ops_table[KVM_DEV_TYPE_MAX] = { #ifdef CONFIG_KVM_MPIC - case KVM_DEV_TYPE_FSL_MPIC_20: - case KVM_DEV_TYPE_FSL_MPIC_42: - ops = &kvm_mpic_ops; - break; + [KVM_DEV_TYPE_FSL_MPIC_20] = &kvm_mpic_ops, + [KVM_DEV_TYPE_FSL_MPIC_42] = &kvm_mpic_ops, #endif + #ifdef CONFIG_KVM_XICS - case KVM_DEV_TYPE_XICS: - ops = &kvm_xics_ops; - break; + [KVM_DEV_TYPE_XICS] = &kvm_xics_ops, #endif + #ifdef CONFIG_KVM_VFIO - case KVM_DEV_TYPE_VFIO: - ops = &kvm_vfio_ops; - break; + [KVM_DEV_TYPE_VFIO] = &kvm_vfio_ops, #endif + #ifdef CONFIG_KVM_ARM_VGIC - case KVM_DEV_TYPE_ARM_VGIC_V2: - ops = &kvm_arm_vgic_v2_ops; - break; + [KVM_DEV_TYPE_ARM_VGIC_V2] = &kvm_arm_vgic_v2_ops, #endif + #ifdef CONFIG_S390 - case KVM_DEV_TYPE_FLIC: - ops = &kvm_flic_ops; - break; + [KVM_DEV_TYPE_FLIC] = &kvm_flic_ops; #endif - default: +}; + +int kvm_register_device_ops(struct kvm_device_ops *ops, u32 type) +{ + if (type >= KVM_DEV_TYPE_MAX) + return -ENOSPC; + + if (kvm_device_ops_table[type] != NULL) + return -EEXIST; + + kvm_device_ops_table[type] = ops; + return 0; +} + +static int kvm_ioctl_create_device(struct kvm *kvm, + struct kvm_create_device *cd) +{ + struct kvm_device_ops *ops = NULL; + struct kvm_device *dev; + bool test = cd->flags & KVM_CREATE_DEVICE_TEST; + int ret; + + if (cd->type >= KVM_DEV_TYPE_MAX) + return -ENODEV; + + ops = kvm_device_ops_table[cd->type]; + if (ops == NULL) return -ENODEV; - } if (test) return 0; -- 2.0.0 -- 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
