| Message ID | 20210919063848.1476776-16-yi.l.liu@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Introduce /dev/iommu for userspace I/O address space management | expand |
On Sun, Sep 19, 2021 at 02:38:43PM +0800, Liu Yi L wrote: > This patch adds interface for userspace to attach device to specified > IOASID. > > Note: > One device can only be attached to one IOASID in this version. This is > on par with what vfio provides today. In the future this restriction can > be relaxed when multiple I/O address spaces are supported per device ?? In VFIO the container is the IOS and the container can be shared with multiple devices. This needs to start at about the same functionality. > + } else if (cmd == VFIO_DEVICE_ATTACH_IOASID) { This should be in the core code, right? There is nothing PCI specific here. Jason
> From: Jason Gunthorpe <jgg@nvidia.com> > Sent: Wednesday, September 22, 2021 2:04 AM > > On Sun, Sep 19, 2021 at 02:38:43PM +0800, Liu Yi L wrote: > > This patch adds interface for userspace to attach device to specified > > IOASID. > > > > Note: > > One device can only be attached to one IOASID in this version. This is > > on par with what vfio provides today. In the future this restriction can > > be relaxed when multiple I/O address spaces are supported per device > > ?? In VFIO the container is the IOS and the container can be shared > with multiple devices. This needs to start at about the same > functionality. a device can be only attached to one container. One container can be shared by multiple devices. a device can be only attached to one IOASID. One IOASID can be shared by multiple devices. it does start at the same functionality. > > > + } else if (cmd == VFIO_DEVICE_ATTACH_IOASID) { > > This should be in the core code, right? There is nothing PCI specific > here. > but if you insist on a pci-wrapper attach function, we still need something here (e.g. with .attach_ioasid() callback)?
On Wed, Sep 22, 2021 at 03:56:18AM +0000, Tian, Kevin wrote: > > From: Jason Gunthorpe <jgg@nvidia.com> > > Sent: Wednesday, September 22, 2021 2:04 AM > > > > On Sun, Sep 19, 2021 at 02:38:43PM +0800, Liu Yi L wrote: > > > This patch adds interface for userspace to attach device to specified > > > IOASID. > > > > > > Note: > > > One device can only be attached to one IOASID in this version. This is > > > on par with what vfio provides today. In the future this restriction can > > > be relaxed when multiple I/O address spaces are supported per device > > > > ?? In VFIO the container is the IOS and the container can be shared > > with multiple devices. This needs to start at about the same > > functionality. > > a device can be only attached to one container. One container can be > shared by multiple devices. > > a device can be only attached to one IOASID. One IOASID can be shared > by multiple devices. > > it does start at the same functionality. > > > > > > + } else if (cmd == VFIO_DEVICE_ATTACH_IOASID) { > > > > This should be in the core code, right? There is nothing PCI specific > > here. > > > > but if you insist on a pci-wrapper attach function, we still need something > here (e.g. with .attach_ioasid() callback)? I would like to stop adding ioctls to this switch, the core code should decode the ioctl and call an per-ioctl op like every other subsystem does.. If you do that then you could have an op .attach_ioasid = vfio_full_device_attach, And that is it for driver changes. Every driver that use type1 today should be updated to have the above line and will work with iommufd. mdevs will not be updated and won't work. Jason
> From: Jason Gunthorpe <jgg@nvidia.com> > Sent: Wednesday, September 22, 2021 8:59 PM > > On Wed, Sep 22, 2021 at 03:56:18AM +0000, Tian, Kevin wrote: > > > From: Jason Gunthorpe <jgg@nvidia.com> > > > Sent: Wednesday, September 22, 2021 2:04 AM > > > > > > On Sun, Sep 19, 2021 at 02:38:43PM +0800, Liu Yi L wrote: > > > > This patch adds interface for userspace to attach device to specified > > > > IOASID. > > > > > > > > Note: > > > > One device can only be attached to one IOASID in this version. This is > > > > on par with what vfio provides today. In the future this restriction can > > > > be relaxed when multiple I/O address spaces are supported per device > > > > > > ?? In VFIO the container is the IOS and the container can be shared > > > with multiple devices. This needs to start at about the same > > > functionality. > > > > a device can be only attached to one container. One container can be > > shared by multiple devices. > > > > a device can be only attached to one IOASID. One IOASID can be shared > > by multiple devices. > > > > it does start at the same functionality. > > > > > > > > > + } else if (cmd == VFIO_DEVICE_ATTACH_IOASID) { > > > > > > This should be in the core code, right? There is nothing PCI specific > > > here. > > > > > > > but if you insist on a pci-wrapper attach function, we still need something > > here (e.g. with .attach_ioasid() callback)? > > I would like to stop adding ioctls to this switch, the core code > should decode the ioctl and call an per-ioctl op like every other > subsystem does.. > > If you do that then you could have an op > > .attach_ioasid = vfio_full_device_attach, > > And that is it for driver changes. > > Every driver that use type1 today should be updated to have the above > line and will work with iommufd. mdevs will not be updated and won't > work. > will do.
diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c index 20006bb66430..5b1fda333122 100644 --- a/drivers/vfio/pci/vfio_pci.c +++ b/drivers/vfio/pci/vfio_pci.c @@ -557,6 +557,11 @@ static void vfio_pci_release(struct vfio_device *core_vdev) if (vdev->videv) { struct vfio_iommufd_device *videv = vdev->videv; + if (videv->ioasid != IOMMUFD_INVALID_IOASID) { + iommufd_device_detach_ioasid(videv->idev, + videv->ioasid); + videv->ioasid = IOMMUFD_INVALID_IOASID; + } vdev->videv = NULL; iommufd_unbind_device(videv->idev); kfree(videv); @@ -839,6 +844,7 @@ static long vfio_pci_ioctl(struct vfio_device *core_vdev, } videv->idev = idev; videv->iommu_fd = bind_data.iommu_fd; + videv->ioasid = IOMMUFD_INVALID_IOASID; /* * A security context has been established. Unblock * user access. @@ -848,6 +854,82 @@ static long vfio_pci_ioctl(struct vfio_device *core_vdev, vdev->videv = videv; mutex_unlock(&vdev->videv_lock); + return 0; + } else if (cmd == VFIO_DEVICE_ATTACH_IOASID) { + struct vfio_device_attach_ioasid attach; + unsigned long minsz; + struct vfio_iommufd_device *videv; + int ret = 0; + + /* not allowed if the device is opened in legacy interface */ + if (vfio_device_in_container(core_vdev)) + return -ENOTTY; + + minsz = offsetofend(struct vfio_device_attach_ioasid, ioasid); + if (copy_from_user(&attach, (void __user *)arg, minsz)) + return -EFAULT; + + if (attach.argsz < minsz || attach.flags || + attach.iommu_fd < 0 || attach.ioasid < 0) + return -EINVAL; + + mutex_lock(&vdev->videv_lock); + + videv = vdev->videv; + if (!videv || videv->iommu_fd != attach.iommu_fd) { + mutex_unlock(&vdev->videv_lock); + return -EINVAL; + } + + /* Currently only allows one IOASID attach */ + if (videv->ioasid != IOMMUFD_INVALID_IOASID) { + mutex_unlock(&vdev->videv_lock); + return -EBUSY; + } + + ret = __pci_iommufd_device_attach_ioasid(vdev->pdev, + videv->idev, + attach.ioasid); + if (!ret) + videv->ioasid = attach.ioasid; + mutex_unlock(&vdev->videv_lock); + + return ret; + } else if (cmd == VFIO_DEVICE_DETACH_IOASID) { + struct vfio_device_attach_ioasid attach; + unsigned long minsz; + struct vfio_iommufd_device *videv; + + /* not allowed if the device is opened in legacy interface */ + if (vfio_device_in_container(core_vdev)) + return -ENOTTY; + + minsz = offsetofend(struct vfio_device_attach_ioasid, ioasid); + if (copy_from_user(&attach, (void __user *)arg, minsz)) + return -EFAULT; + + if (attach.argsz < minsz || attach.flags || + attach.iommu_fd < 0 || attach.ioasid < 0) + return -EINVAL; + + mutex_lock(&vdev->videv_lock); + + videv = vdev->videv; + if (!videv || videv->iommu_fd != attach.iommu_fd) { + mutex_unlock(&vdev->videv_lock); + return -EINVAL; + } + + if (videv->ioasid == IOMMUFD_INVALID_IOASID || + videv->ioasid != attach.ioasid) { + mutex_unlock(&vdev->videv_lock); + return -EINVAL; + } + + videv->ioasid = IOMMUFD_INVALID_IOASID; + iommufd_device_detach_ioasid(videv->idev, attach.ioasid); + mutex_unlock(&vdev->videv_lock); + return 0; } else if (cmd == VFIO_DEVICE_GET_INFO) { struct vfio_device_info info; diff --git a/drivers/vfio/pci/vfio_pci_private.h b/drivers/vfio/pci/vfio_pci_private.h index bd784accac35..daa0f08ac835 100644 --- a/drivers/vfio/pci/vfio_pci_private.h +++ b/drivers/vfio/pci/vfio_pci_private.h @@ -103,6 +103,7 @@ struct vfio_pci_mmap_vma { struct vfio_iommufd_device { struct iommufd_device *idev; int iommu_fd; + int ioasid; }; struct vfio_pci_device { diff --git a/include/linux/iommufd.h b/include/linux/iommufd.h index 01a4fe934143..36d8d2fd22bb 100644 --- a/include/linux/iommufd.h +++ b/include/linux/iommufd.h @@ -17,6 +17,7 @@ #define IOMMUFD_IOASID_MAX ((unsigned int)(0x7FFFFFFF)) #define IOMMUFD_IOASID_MIN 0 +#define IOMMUFD_INVALID_IOASID -1 #define IOMMUFD_DEVID_MAX ((unsigned int)(0x7FFFFFFF)) #define IOMMUFD_DEVID_MIN 0 diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h index c902abd60339..61493ab03038 100644 --- a/include/uapi/linux/vfio.h +++ b/include/uapi/linux/vfio.h @@ -220,6 +220,32 @@ struct vfio_device_iommu_bind_data { #define VFIO_DEVICE_BIND_IOMMUFD _IO(VFIO_TYPE, VFIO_BASE + 19) +/* + * VFIO_DEVICE_ATTACH_IOASID - _IOW(VFIO_TYPE, VFIO_BASE + 21, + * struct vfio_device_attach_ioasid) + * + * Attach a vfio device to the specified IOASID + * + * Multiple vfio devices can be attached to the same IOASID. One device can + * be attached to only one ioasid at this point. + * + * @argsz: user filled size of this data. + * @flags: reserved for future extension. + * @iommu_fd: iommufd where the ioasid comes from. + * @ioasid: target I/O address space. + * + * Return: 0 on success, -errno on failure. + */ +struct vfio_device_attach_ioasid { + __u32 argsz; + __u32 flags; + __s32 iommu_fd; + __s32 ioasid; +}; + +#define VFIO_DEVICE_ATTACH_IOASID _IO(VFIO_TYPE, VFIO_BASE + 20) +#define VFIO_DEVICE_DETACH_IOASID _IO(VFIO_TYPE, VFIO_BASE + 21) + /** * VFIO_DEVICE_GET_INFO - _IOR(VFIO_TYPE, VFIO_BASE + 7, * struct vfio_device_info)
This patch adds interface for userspace to attach device to specified IOASID. Note: One device can only be attached to one IOASID in this version. This is on par with what vfio provides today. In the future this restriction can be relaxed when multiple I/O address spaces are supported per device Signed-off-by: Liu Yi L <yi.l.liu@intel.com> --- drivers/vfio/pci/vfio_pci.c | 82 +++++++++++++++++++++++++++++ drivers/vfio/pci/vfio_pci_private.h | 1 + include/linux/iommufd.h | 1 + include/uapi/linux/vfio.h | 26 +++++++++ 4 files changed, 110 insertions(+)