diff --git a/drivers/vfio/iommufd.c b/drivers/vfio/iommufd.c index 88b00c501015..afda47ee9663 100644 --- a/drivers/vfio/iommufd.c +++ b/drivers/vfio/iommufd.c @@ -66,6 +66,50 @@ void vfio_iommufd_unbind(struct vfio_device *vdev) vdev->ops->unbind_iommufd(vdev); } +struct iommufd_ctx *vfio_iommufd_device_ictx(struct vfio_device *vdev) +{ + if (vdev->iommufd_device) + return iommufd_device_to_ictx(vdev->iommufd_device); + return NULL; +} +EXPORT_SYMBOL_GPL(vfio_iommufd_device_ictx); + +static int vfio_iommufd_device_id(struct vfio_device *vdev) +{ + if (vdev->iommufd_device) + return iommufd_device_to_id(vdev->iommufd_device); + return -EINVAL; +} + +/* + * Return devid for a device. + * valid ID for the device that is owned by the ictx + * -ENOENT = device is owned but there is no ID + * -ENODEV or other error = device is not owned + */ +int vfio_iommufd_get_dev_id(struct vfio_device *vdev, struct iommufd_ctx *ictx) +{ + struct iommu_group *group; + int devid; + + if (vfio_iommufd_device_ictx(vdev) == ictx) + return vfio_iommufd_device_id(vdev); + + group = iommu_group_get(vdev->dev); + if (!group) + return -ENODEV; + + if (iommufd_ctx_has_group(ictx, group)) + devid = -ENOENT; + else + devid = -ENODEV; + + iommu_group_put(group); + + return devid; +} +EXPORT_SYMBOL_GPL(vfio_iommufd_get_dev_id); + /* * The physical standard ops mean that the iommufd_device is bound to the * physical device vdev->dev that was provided to vfio_init_group_dev(). Drivers diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c index 5b5316a5484a..32506c5539b9 100644 --- a/drivers/vfio/pci/vfio_pci_core.c +++ b/drivers/vfio/pci/vfio_pci_core.c @@ -27,6 +27,7 @@ #include #include #include +#include #if IS_ENABLED(CONFIG_EEH) #include #endif @@ -779,26 +780,56 @@ struct vfio_pci_fill_info { int max; int cur; struct vfio_pci_dependent_device *devices; + struct vfio_device *vdev; + u32 flags; }; static int vfio_pci_fill_devs(struct pci_dev *pdev, void *data) { struct vfio_pci_fill_info *fill = data; - struct iommu_group *iommu_group; if (fill->cur == fill->max) return -EAGAIN; /* Something changed, try again */ - iommu_group = iommu_group_get(&pdev->dev); - if (!iommu_group) - return -EPERM; /* Cannot reset non-isolated devices */ + if (fill->flags & VFIO_PCI_HOT_RESET_FLAG_DEV_ID) { + struct iommufd_ctx *iommufd = vfio_iommufd_device_ictx(fill->vdev); + struct vfio_device_set *dev_set = fill->vdev->dev_set; + struct vfio_device *vdev; - fill->devices[fill->cur].group_id = iommu_group_id(iommu_group); + /* + * hot-reset requires all affected devices be represented in + * the dev_set. + */ + vdev = vfio_find_device_in_devset(dev_set, &pdev->dev); + if (!vdev) { + fill->devices[fill->cur].devid = VFIO_PCI_DEVID_NOT_OWNED; + } else { + int id = vfio_iommufd_get_dev_id(vdev, iommufd); + + if (id > 0) + fill->devices[fill->cur].devid = id; + else if (id == -ENOENT) + fill->devices[fill->cur].devid = VFIO_PCI_DEVID_OWNED; + else + fill->devices[fill->cur].devid = VFIO_PCI_DEVID_NOT_OWNED; + } + /* If devid is VFIO_PCI_DEVID_NOT_OWNED, clear owned flag. */ + if (fill->devices[fill->cur].devid == VFIO_PCI_DEVID_NOT_OWNED) + fill->flags &= ~VFIO_PCI_HOT_RESET_FLAG_DEV_ID_OWNED; + } else { + struct iommu_group *iommu_group; + + iommu_group = iommu_group_get(&pdev->dev); + if (!iommu_group) + return -EPERM; /* Cannot reset non-isolated devices */ + + fill->devices[fill->cur].group_id = iommu_group_id(iommu_group); + iommu_group_put(iommu_group); + } fill->devices[fill->cur].segment = pci_domain_nr(pdev->bus); fill->devices[fill->cur].bus = pdev->bus->number; fill->devices[fill->cur].devfn = pdev->devfn; fill->cur++; - iommu_group_put(iommu_group); return 0; } @@ -1270,17 +1301,26 @@ static int vfio_pci_ioctl_get_pci_hot_reset_info( return -ENOMEM; fill.devices = devices; + fill.vdev = &vdev->vdev; + if (vfio_device_cdev_opened(&vdev->vdev)) + fill.flags |= VFIO_PCI_HOT_RESET_FLAG_DEV_ID | + VFIO_PCI_HOT_RESET_FLAG_DEV_ID_OWNED; + + mutex_lock(&vdev->vdev.dev_set->lock); ret = vfio_pci_for_each_slot_or_bus(vdev->pdev, vfio_pci_fill_devs, &fill, slot); + mutex_unlock(&vdev->vdev.dev_set->lock); /* * If a device was removed between counting and filling, we may come up * short of fill.max. If a device was added, we'll have a return of * -EAGAIN above. */ - if (!ret) + if (!ret) { hdr.count = fill.cur; + hdr.flags = fill.flags; + } reset_info_exit: if (copy_to_user(arg, &hdr, minsz)) diff --git a/include/linux/vfio.h b/include/linux/vfio.h index ee120d2d530b..7079911edfb1 100644 --- a/include/linux/vfio.h +++ b/include/linux/vfio.h @@ -114,6 +114,8 @@ struct vfio_device_ops { }; #if IS_ENABLED(CONFIG_IOMMUFD) +struct iommufd_ctx *vfio_iommufd_device_ictx(struct vfio_device *vdev); +int vfio_iommufd_get_dev_id(struct vfio_device *vdev, struct iommufd_ctx *ictx); int vfio_iommufd_physical_bind(struct vfio_device *vdev, struct iommufd_ctx *ictx, u32 *out_device_id); void vfio_iommufd_physical_unbind(struct vfio_device *vdev); @@ -123,6 +125,18 @@ int vfio_iommufd_emulated_bind(struct vfio_device *vdev, void vfio_iommufd_emulated_unbind(struct vfio_device *vdev); int vfio_iommufd_emulated_attach_ioas(struct vfio_device *vdev, u32 *pt_id); #else +static inline struct iommufd_ctx * +vfio_iommufd_device_ictx(struct vfio_device *vdev) +{ + return NULL; +} + +static inline int +vfio_iommufd_get_dev_id(struct vfio_device *vdev, struct iommufd_ctx *ictx) +{ + return VFIO_PCI_DEVID_NOT_OWNED; +} + #define vfio_iommufd_physical_bind \ ((int (*)(struct vfio_device *vdev, struct iommufd_ctx *ictx, \ u32 *out_device_id)) NULL) diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h index 20c804bdc09c..e680720ddddc 100644 --- a/include/uapi/linux/vfio.h +++ b/include/uapi/linux/vfio.h @@ -677,11 +677,57 @@ enum { * VFIO_DEVICE_GET_PCI_HOT_RESET_INFO - _IOWR(VFIO_TYPE, VFIO_BASE + 12, * struct vfio_pci_hot_reset_info) * + * This command is used to query the affected devices in the hot reset for + * a given device. + * + * This command always reports the segment, bus, and devfn information for + * each affected device, and selectively reports the group_id or devid per + * the way how the calling device is opened. + * + * - If the calling device is opened via the traditional group/container + * API, group_id is reported. User should check if it has owned all + * the affected devices and provides a set of group fds to prove the + * ownership in VFIO_DEVICE_PCI_HOT_RESET ioctl. + * + * - If the calling device is opened as a cdev, devid is reported. + * Flag VFIO_PCI_HOT_RESET_FLAG_DEV_ID is set to indicate this + * data type. All the affected devices should be represented in + * the dev_set, ex. bound to a vfio driver, and also be owned by + * this interface which is determined by the following conditions: + * 1) Has a valid devid within the iommufd_ctx of the calling device. + * Ownership cannot be determined across separate iommufd_ctx and + * the cdev calling conventions do not support a proof-of-ownership + * model as provided in the legacy group interface. In this case + * valid devid with value greater than zero is provided in the return + * structure. + * 2) Does not have a valid devid within the iommufd_ctx of the calling + * device, but belongs to the same IOMMU group as the calling device + * or another opened device that has a valid devid within the + * iommufd_ctx of the calling device. This provides implicit ownership + * for devices within the same DMA isolation context. In this case + * the devid value of VFIO_PCI_DEVID_OWNED is provided in the return + * structure. + * + * A devid value of VFIO_PCI_DEVID_NOT_OWNED is provided in the return + * structure for affected devices where device is NOT represented in the + * dev_set or ownership is not available. Such devices prevent the use + * of VFIO_DEVICE_PCI_HOT_RESET ioctl outside of the proof-of-ownership + * calling conventions (ie. via legacy group accessed devices). Flag + * VFIO_PCI_HOT_RESET_FLAG_DEV_ID_OWNED would be set when all the + * affected devices are represented in the dev_set and also owned by + * the user. This flag is available only when + * flag VFIO_PCI_HOT_RESET_FLAG_DEV_ID is set, otherwise reserved. + * * Return: 0 on success, -errno on failure: * -enospc = insufficient buffer, -enodev = unsupported for device. */ struct vfio_pci_dependent_device { - __u32 group_id; + union { + __u32 group_id; + __u32 devid; +#define VFIO_PCI_DEVID_OWNED 0 +#define VFIO_PCI_DEVID_NOT_OWNED -1 + }; __u16 segment; __u8 bus; __u8 devfn; /* Use PCI_SLOT/PCI_FUNC */ @@ -690,6 +736,8 @@ struct vfio_pci_dependent_device { struct vfio_pci_hot_reset_info { __u32 argsz; __u32 flags; +#define VFIO_PCI_HOT_RESET_FLAG_DEV_ID (1 << 0) +#define VFIO_PCI_HOT_RESET_FLAG_DEV_ID_OWNED (1 << 1) __u32 count; struct vfio_pci_dependent_device devices[]; };