diff options
| -rw-r--r-- | drivers/vfio/Kconfig | 1 | ||||
| -rw-r--r-- | drivers/vfio/pci/vfio_pci_core.c | 5 | ||||
| -rw-r--r-- | drivers/vfio/vfio_main.c | 175 | ||||
| -rw-r--r-- | include/linux/vfio.h | 28 |
4 files changed, 207 insertions, 2 deletions
diff --git a/drivers/vfio/Kconfig b/drivers/vfio/Kconfig index 6130d00252ed..86c381ceb9a1 100644 --- a/drivers/vfio/Kconfig +++ b/drivers/vfio/Kconfig @@ -3,6 +3,7 @@ menuconfig VFIO tristate "VFIO Non-Privileged userspace driver framework" select IOMMU_API select VFIO_IOMMU_TYPE1 if MMU && (X86 || S390 || ARM || ARM64) + select INTERVAL_TREE help VFIO provides a framework for secure userspace device drivers. See Documentation/driver-api/vfio.rst for more details. diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c index 0d4b49f06b14..0a801aee2f2d 100644 --- a/drivers/vfio/pci/vfio_pci_core.c +++ b/drivers/vfio/pci/vfio_pci_core.c @@ -2128,6 +2128,11 @@ int vfio_pci_core_register_device(struct vfio_pci_core_device *vdev) return -EINVAL; } + if (vdev->vdev.log_ops && !(vdev->vdev.log_ops->log_start && + vdev->vdev.log_ops->log_stop && + vdev->vdev.log_ops->log_read_and_clear)) + return -EINVAL; + /* * Prevent binding to PFs with VFs enabled, the VFs might be in use * by the host or other users. We cannot capture the VFs if they diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c index 77264d836d52..27d9186f35d5 100644 --- a/drivers/vfio/vfio_main.c +++ b/drivers/vfio/vfio_main.c @@ -33,6 +33,8 @@ #include <linux/wait.h> #include <linux/sched/signal.h> #include <linux/pm_runtime.h> +#include <linux/interval_tree.h> +#include <linux/iova_bitmap.h> #include "vfio.h" #define DRIVER_VERSION "0.3" @@ -1658,6 +1660,167 @@ static int vfio_ioctl_device_feature_migration(struct vfio_device *device, return 0; } +/* Ranges should fit into a single kernel page */ +#define LOG_MAX_RANGES \ + (PAGE_SIZE / sizeof(struct vfio_device_feature_dma_logging_range)) + +static int +vfio_ioctl_device_feature_logging_start(struct vfio_device *device, + u32 flags, void __user *arg, + size_t argsz) +{ + size_t minsz = + offsetofend(struct vfio_device_feature_dma_logging_control, + ranges); + struct vfio_device_feature_dma_logging_range __user *ranges; + struct vfio_device_feature_dma_logging_control control; + struct vfio_device_feature_dma_logging_range range; + struct rb_root_cached root = RB_ROOT_CACHED; + struct interval_tree_node *nodes; + u64 iova_end; + u32 nnodes; + int i, ret; + + if (!device->log_ops) + return -ENOTTY; + + ret = vfio_check_feature(flags, argsz, + VFIO_DEVICE_FEATURE_SET, + sizeof(control)); + if (ret != 1) + return ret; + + if (copy_from_user(&control, arg, minsz)) + return -EFAULT; + + nnodes = control.num_ranges; + if (!nnodes) + return -EINVAL; + + if (nnodes > LOG_MAX_RANGES) + return -E2BIG; + + ranges = u64_to_user_ptr(control.ranges); + nodes = kmalloc_array(nnodes, sizeof(struct interval_tree_node), + GFP_KERNEL); + if (!nodes) + return -ENOMEM; + + for (i = 0; i < nnodes; i++) { + if (copy_from_user(&range, &ranges[i], sizeof(range))) { + ret = -EFAULT; + goto end; + } + if (!IS_ALIGNED(range.iova, control.page_size) || + !IS_ALIGNED(range.length, control.page_size)) { + ret = -EINVAL; + goto end; + } + + if (check_add_overflow(range.iova, range.length, &iova_end) || + iova_end > ULONG_MAX) { + ret = -EOVERFLOW; + goto end; + } + + nodes[i].start = range.iova; + nodes[i].last = range.iova + range.length - 1; + if (interval_tree_iter_first(&root, nodes[i].start, + nodes[i].last)) { + /* Range overlapping */ + ret = -EINVAL; + goto end; + } + interval_tree_insert(nodes + i, &root); + } + + ret = device->log_ops->log_start(device, &root, nnodes, + &control.page_size); + if (ret) + goto end; + + if (copy_to_user(arg, &control, sizeof(control))) { + ret = -EFAULT; + device->log_ops->log_stop(device); + } + +end: + kfree(nodes); + return ret; +} + +static int +vfio_ioctl_device_feature_logging_stop(struct vfio_device *device, + u32 flags, void __user *arg, + size_t argsz) +{ + int ret; + + if (!device->log_ops) + return -ENOTTY; + + ret = vfio_check_feature(flags, argsz, + VFIO_DEVICE_FEATURE_SET, 0); + if (ret != 1) + return ret; + + return device->log_ops->log_stop(device); +} + +static int vfio_device_log_read_and_clear(struct iova_bitmap *iter, + unsigned long iova, size_t length, + void *opaque) +{ + struct vfio_device *device = opaque; + + return device->log_ops->log_read_and_clear(device, iova, length, iter); +} + +static int +vfio_ioctl_device_feature_logging_report(struct vfio_device *device, + u32 flags, void __user *arg, + size_t argsz) +{ + size_t minsz = + offsetofend(struct vfio_device_feature_dma_logging_report, + bitmap); + struct vfio_device_feature_dma_logging_report report; + struct iova_bitmap *iter; + u64 iova_end; + int ret; + + if (!device->log_ops) + return -ENOTTY; + + ret = vfio_check_feature(flags, argsz, + VFIO_DEVICE_FEATURE_GET, + sizeof(report)); + if (ret != 1) + return ret; + + if (copy_from_user(&report, arg, minsz)) + return -EFAULT; + + if (report.page_size < SZ_4K || !is_power_of_2(report.page_size)) + return -EINVAL; + + if (check_add_overflow(report.iova, report.length, &iova_end) || + iova_end > ULONG_MAX) + return -EOVERFLOW; + + iter = iova_bitmap_alloc(report.iova, report.length, + report.page_size, + u64_to_user_ptr(report.bitmap)); + if (IS_ERR(iter)) + return PTR_ERR(iter); + + ret = iova_bitmap_for_each(iter, device, + vfio_device_log_read_and_clear); + + iova_bitmap_free(iter); + return ret; +} + static int vfio_ioctl_device_feature(struct vfio_device *device, struct vfio_device_feature __user *arg) { @@ -1691,6 +1854,18 @@ static int vfio_ioctl_device_feature(struct vfio_device *device, return vfio_ioctl_device_feature_mig_device_state( device, feature.flags, arg->data, feature.argsz - minsz); + case VFIO_DEVICE_FEATURE_DMA_LOGGING_START: + return vfio_ioctl_device_feature_logging_start( + device, feature.flags, arg->data, + feature.argsz - minsz); + case VFIO_DEVICE_FEATURE_DMA_LOGGING_STOP: + return vfio_ioctl_device_feature_logging_stop( + device, feature.flags, arg->data, + feature.argsz - minsz); + case VFIO_DEVICE_FEATURE_DMA_LOGGING_REPORT: + return vfio_ioctl_device_feature_logging_report( + device, feature.flags, arg->data, + feature.argsz - minsz); default: if (unlikely(!device->ops->device_feature)) return -EINVAL; diff --git a/include/linux/vfio.h b/include/linux/vfio.h index e05ddc6fe6a5..0e2826559091 100644 --- a/include/linux/vfio.h +++ b/include/linux/vfio.h @@ -14,6 +14,7 @@ #include <linux/workqueue.h> #include <linux/poll.h> #include <uapi/linux/vfio.h> +#include <linux/iova_bitmap.h> struct kvm; @@ -33,10 +34,11 @@ struct vfio_device { struct device *dev; const struct vfio_device_ops *ops; /* - * mig_ops is a static property of the vfio_device which must be set - * prior to registering the vfio_device. + * mig_ops/log_ops is a static property of the vfio_device which must + * be set prior to registering the vfio_device. */ const struct vfio_migration_ops *mig_ops; + const struct vfio_log_ops *log_ops; struct vfio_group *group; struct vfio_device_set *dev_set; struct list_head dev_set_list; @@ -109,6 +111,28 @@ struct vfio_migration_ops { }; /** + * @log_start: Optional callback to ask the device start DMA logging. + * @log_stop: Optional callback to ask the device stop DMA logging. + * @log_read_and_clear: Optional callback to ask the device read + * and clear the dirty DMAs in some given range. + * + * The vfio core implementation of the DEVICE_FEATURE_DMA_LOGGING_ set + * of features does not track logging state relative to the device, + * therefore the device implementation of vfio_log_ops must handle + * arbitrary user requests. This includes rejecting subsequent calls + * to log_start without an intervening log_stop, as well as graceful + * handling of log_stop and log_read_and_clear from invalid states. + */ +struct vfio_log_ops { + int (*log_start)(struct vfio_device *device, + struct rb_root_cached *ranges, u32 nnodes, u64 *page_size); + int (*log_stop)(struct vfio_device *device); + int (*log_read_and_clear)(struct vfio_device *device, + unsigned long iova, unsigned long length, + struct iova_bitmap *dirty); +}; + +/** * vfio_check_feature - Validate user input for the VFIO_DEVICE_FEATURE ioctl * @flags: Arg from the device_feature op * @argsz: Arg from the device_feature op |