RE: [PATCH 08/10] vfio: Move vfio_group_set_kvm() into vfio_file_ops

Tian, Kevin
2022-04-15T04:09:09Z

> From: Jason Gunthorpe <jgg@nvidia.com>
> Sent: Friday, April 15, 2022 2:46 AM
>
> Just move the exported function into the op and have it accept the struct
> file instead of vfio_group.
>
> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

Reviewed-by: Kevin Tian <kevin.tian@intel.com>

> ---
> drivers/vfio/vfio.c | 26 ++++++++++++++++++--------
> include/linux/vfio.h | 5 +++--
> virt/kvm/vfio.c | 19 +++----------------
> 3 files changed, 24 insertions(+), 26 deletions(-)
>
> diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
> index c08093fb6d28d5..2eb63d9dded8fb 100644
> --- a/drivers/vfio/vfio.c
> +++ b/drivers/vfio/vfio.c
> @@ -2029,9 +2029,27 @@ static bool vfio_file_enforced_coherent(struct file
> *filep)
> return ret;
> }
>
> +/**
> + * vfio_file_set_kvm - Link a kvm with VFIO drivers
> + * @filep: VFIO file
> + * @kvm: KVM to link
> + *
> + * The kvm pointer will be forwarded to all the vfio_device's attached to the
> + * VFIO file via the VFIO_GROUP_NOTIFY_SET_KVM notifier.
> + */
> +static void vfio_file_set_kvm(struct file *filep, struct kvm *kvm)
> +{
> + struct vfio_group *group = filep->private_data;
> +
> + group->kvm = kvm;
> + blocking_notifier_call_chain(&group->notifier,
> + VFIO_GROUP_NOTIFY_SET_KVM, kvm);
> +}
> +
> static const struct vfio_file_ops vfio_file_group_ops = {
> .get_iommu_group = vfio_file_iommu_group,
> .is_enforced_coherent = vfio_file_enforced_coherent,
> + .set_kvm = vfio_file_set_kvm,
> };
>
> /**
> @@ -2461,14 +2479,6 @@ static int vfio_unregister_iommu_notifier(struct
> vfio_group *group,
> return ret;
> }
>
> -void vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm)
> -{
> - group->kvm = kvm;
> - blocking_notifier_call_chain(&group->notifier,
> - VFIO_GROUP_NOTIFY_SET_KVM, kvm);
> -}
> -EXPORT_SYMBOL_GPL(vfio_group_set_kvm);
> -
> static int vfio_register_group_notifier(struct vfio_group *group,
> unsigned long *events,
> struct notifier_block *nb)
> diff --git a/include/linux/vfio.h b/include/linux/vfio.h
> index b1583eb80f12e6..bc6e47f3f26560 100644
> --- a/include/linux/vfio.h
> +++ b/include/linux/vfio.h
> @@ -15,6 +15,8 @@
> #include <linux/poll.h>
> #include <uapi/linux/vfio.h>
>
> +struct kvm;
> +
> /*
> * VFIO devices can be placed in a set, this allows all devices to share this
> * structure and the VFIO core will provide a lock that is held around
> @@ -141,6 +143,7 @@ int vfio_mig_get_next_state(struct vfio_device
> *device,
> struct vfio_file_ops {
> struct iommu_group *(*get_iommu_group)(struct file *filep);
> bool (*is_enforced_coherent)(struct file *filep);
> + void (*set_kvm)(struct file *filep, struct kvm *kvm);
> };
> extern struct vfio_group *vfio_group_get_external_user(struct file *filep);
> extern void vfio_group_put_external_user(struct vfio_group *group);
> @@ -186,8 +189,6 @@ extern int vfio_unregister_notifier(struct device *dev,
> enum vfio_notify_type type,
> struct notifier_block *nb);
>
> -struct kvm;
> -extern void vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm);
>
> /*
> * Sub-module helpers
> diff --git a/virt/kvm/vfio.c b/virt/kvm/vfio.c
> index f5ef78192a97ab..9baf04c5b0cc3d 100644
> --- a/virt/kvm/vfio.c
> +++ b/virt/kvm/vfio.c
> @@ -73,19 +73,6 @@ static void kvm_vfio_group_put_external_user(struct
> vfio_group *vfio_group)
> symbol_put(vfio_group_put_external_user);
> }
>
> -static void kvm_vfio_group_set_kvm(struct vfio_group *group, struct kvm
> *kvm)
> -{
> - void (*fn)(struct vfio_group *, struct kvm *);
> -
> - fn = symbol_get(vfio_group_set_kvm);
> - if (!fn)
> - return;
> -
> - fn(group, kvm);
> -
> - symbol_put(vfio_group_set_kvm);
> -}
> -
> static void kvm_spapr_tce_release_vfio_group(struct kvm *kvm,
> struct kvm_vfio_group *kvg)
> {
> @@ -184,7 +171,7 @@ static int kvm_vfio_group_add(struct kvm_device
> *dev, unsigned int fd)
>
> mutex_unlock(&kv->lock);
>
> - kvm_vfio_group_set_kvm(vfio_group, dev->kvm);
> + kvg->ops->set_kvm(kvg->filp, dev->kvm);
> kvm_vfio_update_coherency(dev);
>
> return 0;
> @@ -218,7 +205,7 @@ static int kvm_vfio_group_del(struct kvm_device
> *dev, unsigned int fd)
> list_del(&kvg->node);
> kvm_arch_end_assignment(dev->kvm);
> kvm_spapr_tce_release_vfio_group(dev->kvm, kvg);
> - kvm_vfio_group_set_kvm(kvg->vfio_group, NULL);
> + kvg->ops->set_kvm(kvg->filp, NULL);
> kvm_vfio_group_put_external_user(kvg->vfio_group);
> fput(kvg->filp);
> kfree(kvg);
> @@ -334,7 +321,7 @@ static void kvm_vfio_destroy(struct kvm_device *dev)
>
> list_for_each_entry_safe(kvg, tmp, &kv->group_list, node) {
> kvm_spapr_tce_release_vfio_group(dev->kvm, kvg);
> - kvm_vfio_group_set_kvm(kvg->vfio_group, NULL);
> + kvg->ops->set_kvm(kvg->filp, NULL);
> kvm_vfio_group_put_external_user(kvg->vfio_group);
> fput(kvg->filp);
> list_del(&kvg->node);
> --
> 2.35.1