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path: root/drivers/vfio/vfio.c
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Diffstat (limited to 'drivers/vfio/vfio.c')
-rw-r--r--drivers/vfio/vfio.c296
1 files changed, 292 insertions, 4 deletions
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index 735d1d344af9..a4555014bd1e 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -1557,15 +1557,303 @@ static int vfio_device_fops_release(struct inode *inode, struct file *filep)
return 0;
}
+/*
+ * vfio_mig_get_next_state - Compute the next step in the FSM
+ * @cur_fsm - The current state the device is in
+ * @new_fsm - The target state to reach
+ * @next_fsm - Pointer to the next step to get to new_fsm
+ *
+ * Return 0 upon success, otherwise -errno
+ * Upon success the next step in the state progression between cur_fsm and
+ * new_fsm will be set in next_fsm.
+ *
+ * This breaks down requests for combination transitions into smaller steps and
+ * returns the next step to get to new_fsm. The function may need to be called
+ * multiple times before reaching new_fsm.
+ *
+ */
+int vfio_mig_get_next_state(struct vfio_device *device,
+ enum vfio_device_mig_state cur_fsm,
+ enum vfio_device_mig_state new_fsm,
+ enum vfio_device_mig_state *next_fsm)
+{
+ enum { VFIO_DEVICE_NUM_STATES = VFIO_DEVICE_STATE_RUNNING_P2P + 1 };
+ /*
+ * The coding in this table requires the driver to implement the
+ * following FSM arcs:
+ * RESUMING -> STOP
+ * STOP -> RESUMING
+ * STOP -> STOP_COPY
+ * STOP_COPY -> STOP
+ *
+ * If P2P is supported then the driver must also implement these FSM
+ * arcs:
+ * RUNNING -> RUNNING_P2P
+ * RUNNING_P2P -> RUNNING
+ * RUNNING_P2P -> STOP
+ * STOP -> RUNNING_P2P
+ * Without P2P the driver must implement:
+ * RUNNING -> STOP
+ * STOP -> RUNNING
+ *
+ * The coding will step through multiple states for some combination
+ * transitions; if all optional features are supported, this means the
+ * following ones:
+ * RESUMING -> STOP -> RUNNING_P2P
+ * RESUMING -> STOP -> RUNNING_P2P -> RUNNING
+ * RESUMING -> STOP -> STOP_COPY
+ * RUNNING -> RUNNING_P2P -> STOP
+ * RUNNING -> RUNNING_P2P -> STOP -> RESUMING
+ * RUNNING -> RUNNING_P2P -> STOP -> STOP_COPY
+ * RUNNING_P2P -> STOP -> RESUMING
+ * RUNNING_P2P -> STOP -> STOP_COPY
+ * STOP -> RUNNING_P2P -> RUNNING
+ * STOP_COPY -> STOP -> RESUMING
+ * STOP_COPY -> STOP -> RUNNING_P2P
+ * STOP_COPY -> STOP -> RUNNING_P2P -> RUNNING
+ */
+ static const u8 vfio_from_fsm_table[VFIO_DEVICE_NUM_STATES][VFIO_DEVICE_NUM_STATES] = {
+ [VFIO_DEVICE_STATE_STOP] = {
+ [VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_STOP,
+ [VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_RUNNING_P2P,
+ [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_STOP_COPY,
+ [VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_RESUMING,
+ [VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_RUNNING_P2P,
+ [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR,
+ },
+ [VFIO_DEVICE_STATE_RUNNING] = {
+ [VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_RUNNING_P2P,
+ [VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_RUNNING,
+ [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_RUNNING_P2P,
+ [VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_RUNNING_P2P,
+ [VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_RUNNING_P2P,
+ [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR,
+ },
+ [VFIO_DEVICE_STATE_STOP_COPY] = {
+ [VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_STOP,
+ [VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_STOP,
+ [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_STOP_COPY,
+ [VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_STOP,
+ [VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_STOP,
+ [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR,
+ },
+ [VFIO_DEVICE_STATE_RESUMING] = {
+ [VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_STOP,
+ [VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_STOP,
+ [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_STOP,
+ [VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_RESUMING,
+ [VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_STOP,
+ [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR,
+ },
+ [VFIO_DEVICE_STATE_RUNNING_P2P] = {
+ [VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_STOP,
+ [VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_RUNNING,
+ [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_STOP,
+ [VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_STOP,
+ [VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_RUNNING_P2P,
+ [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR,
+ },
+ [VFIO_DEVICE_STATE_ERROR] = {
+ [VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_ERROR,
+ [VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_ERROR,
+ [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_ERROR,
+ [VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_ERROR,
+ [VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_ERROR,
+ [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR,
+ },
+ };
+
+ static const unsigned int state_flags_table[VFIO_DEVICE_NUM_STATES] = {
+ [VFIO_DEVICE_STATE_STOP] = VFIO_MIGRATION_STOP_COPY,
+ [VFIO_DEVICE_STATE_RUNNING] = VFIO_MIGRATION_STOP_COPY,
+ [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_MIGRATION_STOP_COPY,
+ [VFIO_DEVICE_STATE_RESUMING] = VFIO_MIGRATION_STOP_COPY,
+ [VFIO_DEVICE_STATE_RUNNING_P2P] =
+ VFIO_MIGRATION_STOP_COPY | VFIO_MIGRATION_P2P,
+ [VFIO_DEVICE_STATE_ERROR] = ~0U,
+ };
+
+ if (WARN_ON(cur_fsm >= ARRAY_SIZE(vfio_from_fsm_table) ||
+ (state_flags_table[cur_fsm] & device->migration_flags) !=
+ state_flags_table[cur_fsm]))
+ return -EINVAL;
+
+ if (new_fsm >= ARRAY_SIZE(vfio_from_fsm_table) ||
+ (state_flags_table[new_fsm] & device->migration_flags) !=
+ state_flags_table[new_fsm])
+ return -EINVAL;
+
+ /*
+ * Arcs touching optional and unsupported states are skipped over. The
+ * driver will instead see an arc from the original state to the next
+ * logical state, as per the above comment.
+ */
+ *next_fsm = vfio_from_fsm_table[cur_fsm][new_fsm];
+ while ((state_flags_table[*next_fsm] & device->migration_flags) !=
+ state_flags_table[*next_fsm])
+ *next_fsm = vfio_from_fsm_table[*next_fsm][new_fsm];
+
+ return (*next_fsm != VFIO_DEVICE_STATE_ERROR) ? 0 : -EINVAL;
+}
+EXPORT_SYMBOL_GPL(vfio_mig_get_next_state);
+
+/*
+ * Convert the drivers's struct file into a FD number and return it to userspace
+ */
+static int vfio_ioct_mig_return_fd(struct file *filp, void __user *arg,
+ struct vfio_device_feature_mig_state *mig)
+{
+ int ret;
+ int fd;
+
+ fd = get_unused_fd_flags(O_CLOEXEC);
+ if (fd < 0) {
+ ret = fd;
+ goto out_fput;
+ }
+
+ mig->data_fd = fd;
+ if (copy_to_user(arg, mig, sizeof(*mig))) {
+ ret = -EFAULT;
+ goto out_put_unused;
+ }
+ fd_install(fd, filp);
+ return 0;
+
+out_put_unused:
+ put_unused_fd(fd);
+out_fput:
+ fput(filp);
+ return ret;
+}
+
+static int
+vfio_ioctl_device_feature_mig_device_state(struct vfio_device *device,
+ u32 flags, void __user *arg,
+ size_t argsz)
+{
+ size_t minsz =
+ offsetofend(struct vfio_device_feature_mig_state, data_fd);
+ struct vfio_device_feature_mig_state mig;
+ struct file *filp = NULL;
+ int ret;
+
+ if (!device->ops->migration_set_state ||
+ !device->ops->migration_get_state)
+ return -ENOTTY;
+
+ ret = vfio_check_feature(flags, argsz,
+ VFIO_DEVICE_FEATURE_SET |
+ VFIO_DEVICE_FEATURE_GET,
+ sizeof(mig));
+ if (ret != 1)
+ return ret;
+
+ if (copy_from_user(&mig, arg, minsz))
+ return -EFAULT;
+
+ if (flags & VFIO_DEVICE_FEATURE_GET) {
+ enum vfio_device_mig_state curr_state;
+
+ ret = device->ops->migration_get_state(device, &curr_state);
+ if (ret)
+ return ret;
+ mig.device_state = curr_state;
+ goto out_copy;
+ }
+
+ /* Handle the VFIO_DEVICE_FEATURE_SET */
+ filp = device->ops->migration_set_state(device, mig.device_state);
+ if (IS_ERR(filp) || !filp)
+ goto out_copy;
+
+ return vfio_ioct_mig_return_fd(filp, arg, &mig);
+out_copy:
+ mig.data_fd = -1;
+ if (copy_to_user(arg, &mig, sizeof(mig)))
+ return -EFAULT;
+ if (IS_ERR(filp))
+ return PTR_ERR(filp);
+ return 0;
+}
+
+static int vfio_ioctl_device_feature_migration(struct vfio_device *device,
+ u32 flags, void __user *arg,
+ size_t argsz)
+{
+ struct vfio_device_feature_migration mig = {
+ .flags = device->migration_flags,
+ };
+ int ret;
+
+ if (!device->ops->migration_set_state ||
+ !device->ops->migration_get_state)
+ return -ENOTTY;
+
+ ret = vfio_check_feature(flags, argsz, VFIO_DEVICE_FEATURE_GET,
+ sizeof(mig));
+ if (ret != 1)
+ return ret;
+ if (copy_to_user(arg, &mig, sizeof(mig)))
+ return -EFAULT;
+ return 0;
+}
+
+static int vfio_ioctl_device_feature(struct vfio_device *device,
+ struct vfio_device_feature __user *arg)
+{
+ size_t minsz = offsetofend(struct vfio_device_feature, flags);
+ struct vfio_device_feature feature;
+
+ if (copy_from_user(&feature, arg, minsz))
+ return -EFAULT;
+
+ if (feature.argsz < minsz)
+ return -EINVAL;
+
+ /* Check unknown flags */
+ if (feature.flags &
+ ~(VFIO_DEVICE_FEATURE_MASK | VFIO_DEVICE_FEATURE_SET |
+ VFIO_DEVICE_FEATURE_GET | VFIO_DEVICE_FEATURE_PROBE))
+ return -EINVAL;
+
+ /* GET & SET are mutually exclusive except with PROBE */
+ if (!(feature.flags & VFIO_DEVICE_FEATURE_PROBE) &&
+ (feature.flags & VFIO_DEVICE_FEATURE_SET) &&
+ (feature.flags & VFIO_DEVICE_FEATURE_GET))
+ return -EINVAL;
+
+ switch (feature.flags & VFIO_DEVICE_FEATURE_MASK) {
+ case VFIO_DEVICE_FEATURE_MIGRATION:
+ return vfio_ioctl_device_feature_migration(
+ device, feature.flags, arg->data,
+ feature.argsz - minsz);
+ case VFIO_DEVICE_FEATURE_MIG_DEVICE_STATE:
+ return vfio_ioctl_device_feature_mig_device_state(
+ device, feature.flags, arg->data,
+ feature.argsz - minsz);
+ default:
+ if (unlikely(!device->ops->device_feature))
+ return -EINVAL;
+ return device->ops->device_feature(device, feature.flags,
+ arg->data,
+ feature.argsz - minsz);
+ }
+}
+
static long vfio_device_fops_unl_ioctl(struct file *filep,
unsigned int cmd, unsigned long arg)
{
struct vfio_device *device = filep->private_data;
- if (unlikely(!device->ops->ioctl))
- return -EINVAL;
-
- return device->ops->ioctl(device, cmd, arg);
+ switch (cmd) {
+ case VFIO_DEVICE_FEATURE:
+ return vfio_ioctl_device_feature(device, (void __user *)arg);
+ default:
+ if (unlikely(!device->ops->ioctl))
+ return -EINVAL;
+ return device->ops->ioctl(device, cmd, arg);
+ }
}
static ssize_t vfio_device_fops_read(struct file *filep, char __user *buf,
generated by cgit v1.2.3-58-ga151 (git 2.39.0) at 2024-12-13 17:36:18 +0000