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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.c199
1 files changed, 199 insertions, 0 deletions
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index 71763e2ac561..b37ab27b511f 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -1557,6 +1557,197 @@ 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_RESUMING + 1 };
+ /*
+ * The coding in this table requires the driver to implement 6
+ * FSM arcs:
+ * RESUMING -> STOP
+ * RUNNING -> STOP
+ * STOP -> RESUMING
+ * STOP -> RUNNING
+ * STOP -> STOP_COPY
+ * STOP_COPY -> STOP
+ *
+ * The coding will step through multiple states for these combination
+ * transitions:
+ * RESUMING -> STOP -> RUNNING
+ * RESUMING -> STOP -> STOP_COPY
+ * RUNNING -> STOP -> RESUMING
+ * RUNNING -> STOP -> STOP_COPY
+ * STOP_COPY -> STOP -> RESUMING
+ * STOP_COPY -> STOP -> 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,
+ [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_STOP_COPY,
+ [VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_RESUMING,
+ [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR,
+ },
+ [VFIO_DEVICE_STATE_RUNNING] = {
+ [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_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_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_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_ERROR] = VFIO_DEVICE_STATE_ERROR,
+ },
+ };
+
+ if (WARN_ON(cur_fsm >= ARRAY_SIZE(vfio_from_fsm_table)))
+ return -EINVAL;
+
+ if (new_fsm >= ARRAY_SIZE(vfio_from_fsm_table))
+ return -EINVAL;
+
+ *next_fsm = vfio_from_fsm_table[cur_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 = VFIO_MIGRATION_STOP_COPY,
+ };
+ 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)
{
@@ -1582,6 +1773,14 @@ static int vfio_ioctl_device_feature(struct vfio_device *device,
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;
generated by cgit v1.2.3 (git 2.39.0) at 2025-03-01 01:38:28 +0300