diff options
| -rw-r--r-- | drivers/virtio/virtio_mem.c | 68 | ||||
| -rw-r--r-- | include/uapi/linux/virtio_mem.h | 2 |
2 files changed, 64 insertions, 6 deletions
diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c index 8e3223294442..51088d02de32 100644 --- a/drivers/virtio/virtio_mem.c +++ b/drivers/virtio/virtio_mem.c @@ -21,6 +21,7 @@ #include <linux/bitmap.h> #include <linux/lockdep.h> #include <linux/log2.h> +#include <linux/suspend.h> #include <acpi/acpi_numa.h> @@ -252,6 +253,9 @@ struct virtio_mem { /* Memory notifier (online/offline events). */ struct notifier_block memory_notifier; + /* Notifier to block hibernation image storing/reloading. */ + struct notifier_block pm_notifier; + #ifdef CONFIG_PROC_VMCORE /* vmcore callback for /proc/vmcore handling in kdump mode */ struct vmcore_cb vmcore_cb; @@ -1111,6 +1115,25 @@ static int virtio_mem_memory_notifier_cb(struct notifier_block *nb, return rc; } +static int virtio_mem_pm_notifier_cb(struct notifier_block *nb, + unsigned long action, void *arg) +{ + struct virtio_mem *vm = container_of(nb, struct virtio_mem, + pm_notifier); + switch (action) { + case PM_HIBERNATION_PREPARE: + case PM_RESTORE_PREPARE: + /* + * When restarting the VM, all memory is unplugged. Don't + * allow to hibernate and restore from an image. + */ + dev_err(&vm->vdev->dev, "hibernation is not supported.\n"); + return NOTIFY_BAD; + default: + return NOTIFY_OK; + } +} + /* * Set a range of pages PG_offline. Remember pages that were never onlined * (via generic_online_page()) using PageDirty(). @@ -2615,11 +2638,19 @@ static int virtio_mem_init_hotplug(struct virtio_mem *vm) rc = register_memory_notifier(&vm->memory_notifier); if (rc) goto out_unreg_group; - rc = register_virtio_mem_device(vm); + /* Block hibernation as early as possible. */ + vm->pm_notifier.priority = INT_MAX; + vm->pm_notifier.notifier_call = virtio_mem_pm_notifier_cb; + rc = register_pm_notifier(&vm->pm_notifier); if (rc) goto out_unreg_mem; + rc = register_virtio_mem_device(vm); + if (rc) + goto out_unreg_pm; return 0; +out_unreg_pm: + unregister_pm_notifier(&vm->pm_notifier); out_unreg_mem: unregister_memory_notifier(&vm->memory_notifier); out_unreg_group: @@ -2897,6 +2928,7 @@ static void virtio_mem_deinit_hotplug(struct virtio_mem *vm) /* unregister callbacks */ unregister_virtio_mem_device(vm); + unregister_pm_notifier(&vm->pm_notifier); unregister_memory_notifier(&vm->memory_notifier); /* @@ -2960,17 +2992,40 @@ static void virtio_mem_config_changed(struct virtio_device *vdev) #ifdef CONFIG_PM_SLEEP static int virtio_mem_freeze(struct virtio_device *vdev) { + struct virtio_mem *vm = vdev->priv; + /* - * When restarting the VM, all memory is usually unplugged. Don't - * allow to suspend/hibernate. + * We block hibernation using the PM notifier completely. The workqueue + * is already frozen by the PM core at this point, so we simply + * reset the device and cleanup the queues. */ - dev_err(&vdev->dev, "save/restore not supported.\n"); - return -EPERM; + if (pm_suspend_target_state != PM_SUSPEND_TO_IDLE && + vm->plugged_size && + !virtio_has_feature(vm->vdev, VIRTIO_MEM_F_PERSISTENT_SUSPEND)) { + dev_err(&vm->vdev->dev, + "suspending with plugged memory is not supported\n"); + return -EPERM; + } + + virtio_reset_device(vdev); + vdev->config->del_vqs(vdev); + vm->vq = NULL; + return 0; } static int virtio_mem_restore(struct virtio_device *vdev) { - return -EPERM; + struct virtio_mem *vm = vdev->priv; + int ret; + + ret = virtio_mem_init_vq(vm); + if (ret) + return ret; + virtio_device_ready(vdev); + + /* Let's check if anything changed. */ + virtio_mem_config_changed(vdev); + return 0; } #endif @@ -2979,6 +3034,7 @@ static unsigned int virtio_mem_features[] = { VIRTIO_MEM_F_ACPI_PXM, #endif VIRTIO_MEM_F_UNPLUGGED_INACCESSIBLE, + VIRTIO_MEM_F_PERSISTENT_SUSPEND, }; static const struct virtio_device_id virtio_mem_id_table[] = { diff --git a/include/uapi/linux/virtio_mem.h b/include/uapi/linux/virtio_mem.h index e9122f1d0e0c..6e4b2cf6b7f1 100644 --- a/include/uapi/linux/virtio_mem.h +++ b/include/uapi/linux/virtio_mem.h @@ -90,6 +90,8 @@ #define VIRTIO_MEM_F_ACPI_PXM 0 /* unplugged memory must not be accessed */ #define VIRTIO_MEM_F_UNPLUGGED_INACCESSIBLE 1 +/* plugged memory will remain plugged when suspending+resuming */ +#define VIRTIO_MEM_F_PERSISTENT_SUSPEND 2 /* --- virtio-mem: guest -> host requests --- */ |