lkml.org 
[lkml]   [2021]   [Dec]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH 26/32] vfio-pci/zdev: wire up group notifier
    On Tue,  7 Dec 2021 15:57:37 -0500
    Matthew Rosato <mjrosato@linux.ibm.com> wrote:

    > KVM zPCI passthrough device logic will need a reference to the associated
    > kvm guest that has access to the device. Let's register a group notifier
    > for VFIO_GROUP_NOTIFY_SET_KVM to catch this information in order to create
    > an association between a kvm guest and the host zdev.
    >
    > Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
    > ---
    > arch/s390/include/asm/kvm_pci.h | 2 ++
    > drivers/vfio/pci/vfio_pci_core.c | 2 ++
    > drivers/vfio/pci/vfio_pci_zdev.c | 54 ++++++++++++++++++++++++++++++++
    > include/linux/vfio_pci_core.h | 12 +++++++
    > 4 files changed, 70 insertions(+)
    >
    > diff --git a/arch/s390/include/asm/kvm_pci.h b/arch/s390/include/asm/kvm_pci.h
    > index 97e3a369135d..6526908ac834 100644
    > --- a/arch/s390/include/asm/kvm_pci.h
    > +++ b/arch/s390/include/asm/kvm_pci.h
    > @@ -17,6 +17,7 @@
    > #include <linux/kvm.h>
    > #include <linux/pci.h>
    > #include <linux/mutex.h>
    > +#include <linux/notifier.h>
    > #include <asm/pci_insn.h>
    > #include <asm/pci_dma.h>
    >
    > @@ -33,6 +34,7 @@ struct kvm_zdev {
    > u64 rpcit_count;
    > struct kvm_zdev_ioat ioat;
    > struct zpci_fib fib;
    > + struct notifier_block nb;
    > };
    >
    > extern int kvm_s390_pci_dev_open(struct zpci_dev *zdev);
    > diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
    > index f948e6cd2993..fc57d4d0abbe 100644
    > --- a/drivers/vfio/pci/vfio_pci_core.c
    > +++ b/drivers/vfio/pci/vfio_pci_core.c
    > @@ -452,6 +452,7 @@ void vfio_pci_core_close_device(struct vfio_device *core_vdev)
    >
    > vfio_pci_vf_token_user_add(vdev, -1);
    > vfio_spapr_pci_eeh_release(vdev->pdev);
    > + vfio_pci_zdev_release(vdev);
    > vfio_pci_core_disable(vdev);
    >
    > mutex_lock(&vdev->igate);
    > @@ -470,6 +471,7 @@ EXPORT_SYMBOL_GPL(vfio_pci_core_close_device);
    > void vfio_pci_core_finish_enable(struct vfio_pci_core_device *vdev)
    > {
    > vfio_pci_probe_mmaps(vdev);
    > + vfio_pci_zdev_open(vdev);
    > vfio_spapr_pci_eeh_open(vdev->pdev);
    > vfio_pci_vf_token_user_add(vdev, 1);
    > }
    > diff --git a/drivers/vfio/pci/vfio_pci_zdev.c b/drivers/vfio/pci/vfio_pci_zdev.c
    > index ea4c0d2b0663..cfd7f44b06c1 100644
    > --- a/drivers/vfio/pci/vfio_pci_zdev.c
    > +++ b/drivers/vfio/pci/vfio_pci_zdev.c
    > @@ -13,6 +13,7 @@
    > #include <linux/vfio_zdev.h>
    > #include <asm/pci_clp.h>
    > #include <asm/pci_io.h>
    > +#include <asm/kvm_pci.h>
    >
    > #include <linux/vfio_pci_core.h>
    >
    > @@ -136,3 +137,56 @@ int vfio_pci_info_zdev_add_caps(struct vfio_pci_core_device *vdev,
    >
    > return ret;
    > }
    > +
    > +static int vfio_pci_zdev_group_notifier(struct notifier_block *nb,
    > + unsigned long action, void *data)
    > +{
    > + struct kvm_zdev *kzdev = container_of(nb, struct kvm_zdev, nb);
    > +
    > + if (action == VFIO_GROUP_NOTIFY_SET_KVM) {
    > + if (!data || !kzdev->zdev)
    > + return NOTIFY_DONE;
    > + if (kvm_s390_pci_attach_kvm(kzdev->zdev, data))
    > + return NOTIFY_DONE;
    > + }
    > +
    > + return NOTIFY_OK;
    > +}
    > +
    > +int vfio_pci_zdev_open(struct vfio_pci_core_device *vdev)
    > +{
    > + unsigned long events = VFIO_GROUP_NOTIFY_SET_KVM;
    > + struct zpci_dev *zdev = to_zpci(vdev->pdev);
    > + int ret;
    > +
    > + if (!zdev)
    > + return -ENODEV;
    > +
    > + ret = kvm_s390_pci_dev_open(zdev);
    > + if (ret)
    > + return -ENODEV;
    > +
    > + zdev->kzdev->nb.notifier_call = vfio_pci_zdev_group_notifier;
    > +
    > + ret = vfio_register_notifier(vdev->vdev.dev, VFIO_GROUP_NOTIFY,
    > + &events, &zdev->kzdev->nb);
    > + if (ret)
    > + kvm_s390_pci_dev_release(zdev);
    > +
    > + return ret;

    None of these error return paths are realized by the call site. Thanks,

    Alex

    > +}
    > +
    > +int vfio_pci_zdev_release(struct vfio_pci_core_device *vdev)
    > +{
    > + struct zpci_dev *zdev = to_zpci(vdev->pdev);
    > +
    > + if (!zdev || !zdev->kzdev)
    > + return -ENODEV;
    > +
    > + vfio_unregister_notifier(vdev->vdev.dev, VFIO_GROUP_NOTIFY,
    > + &zdev->kzdev->nb);
    > +
    > + kvm_s390_pci_dev_release(zdev);
    > +
    > + return 0;
    > +}
    > diff --git a/include/linux/vfio_pci_core.h b/include/linux/vfio_pci_core.h
    > index 5e2bca3b89db..14079da409f1 100644
    > --- a/include/linux/vfio_pci_core.h
    > +++ b/include/linux/vfio_pci_core.h
    > @@ -198,12 +198,24 @@ static inline int vfio_pci_igd_init(struct vfio_pci_core_device *vdev)
    > #ifdef CONFIG_VFIO_PCI_ZDEV
    > extern int vfio_pci_info_zdev_add_caps(struct vfio_pci_core_device *vdev,
    > struct vfio_info_cap *caps);
    > +int vfio_pci_zdev_open(struct vfio_pci_core_device *vdev);
    > +int vfio_pci_zdev_release(struct vfio_pci_core_device *vdev);
    > #else
    > static inline int vfio_pci_info_zdev_add_caps(struct vfio_pci_core_device *vdev,
    > struct vfio_info_cap *caps)
    > {
    > return -ENODEV;
    > }
    > +
    > +static inline int vfio_pci_zdev_open(struct vfio_pci_core_device *vdev)
    > +{
    > + return -ENODEV;
    > +}
    > +
    > +static inline int vfio_pci_zdev_release(struct vfio_pci_core_device *vdev)
    > +{
    > + return -ENODEV;
    > +}
    > #endif
    >
    > /* Will be exported for vfio pci drivers usage */

    \
     
     \ /
      Last update: 2021-12-21 19:48    [W:4.066 / U:0.664 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site