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![Michael S. Tsirkin](/assets/img/avatar_default.png)
Virtio mem is modern-only. Use LE accessors for config space. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
1984 lines
53 KiB
C
1984 lines
53 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Virtio-mem device driver.
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*
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* Copyright Red Hat, Inc. 2020
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*
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* Author(s): David Hildenbrand <david@redhat.com>
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*/
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#include <linux/virtio.h>
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#include <linux/virtio_mem.h>
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#include <linux/workqueue.h>
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#include <linux/slab.h>
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#include <linux/module.h>
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#include <linux/mm.h>
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#include <linux/memory_hotplug.h>
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#include <linux/memory.h>
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#include <linux/hrtimer.h>
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#include <linux/crash_dump.h>
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#include <linux/mutex.h>
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#include <linux/bitmap.h>
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#include <linux/lockdep.h>
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#include <acpi/acpi_numa.h>
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static bool unplug_online = true;
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module_param(unplug_online, bool, 0644);
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MODULE_PARM_DESC(unplug_online, "Try to unplug online memory");
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enum virtio_mem_mb_state {
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/* Unplugged, not added to Linux. Can be reused later. */
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VIRTIO_MEM_MB_STATE_UNUSED = 0,
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/* (Partially) plugged, not added to Linux. Error on add_memory(). */
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VIRTIO_MEM_MB_STATE_PLUGGED,
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/* Fully plugged, fully added to Linux, offline. */
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VIRTIO_MEM_MB_STATE_OFFLINE,
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/* Partially plugged, fully added to Linux, offline. */
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VIRTIO_MEM_MB_STATE_OFFLINE_PARTIAL,
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/* Fully plugged, fully added to Linux, online (!ZONE_MOVABLE). */
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VIRTIO_MEM_MB_STATE_ONLINE,
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/* Partially plugged, fully added to Linux, online (!ZONE_MOVABLE). */
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VIRTIO_MEM_MB_STATE_ONLINE_PARTIAL,
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/*
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* Fully plugged, fully added to Linux, online (ZONE_MOVABLE).
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* We are not allowed to allocate (unplug) parts of this block that
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* are not movable (similar to gigantic pages). We will never allow
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* to online OFFLINE_PARTIAL to ZONE_MOVABLE (as they would contain
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* unmovable parts).
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*/
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VIRTIO_MEM_MB_STATE_ONLINE_MOVABLE,
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VIRTIO_MEM_MB_STATE_COUNT
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};
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struct virtio_mem {
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struct virtio_device *vdev;
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/* We might first have to unplug all memory when starting up. */
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bool unplug_all_required;
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/* Workqueue that processes the plug/unplug requests. */
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struct work_struct wq;
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atomic_t config_changed;
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/* Virtqueue for guest->host requests. */
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struct virtqueue *vq;
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/* Wait for a host response to a guest request. */
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wait_queue_head_t host_resp;
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/* Space for one guest request and the host response. */
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struct virtio_mem_req req;
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struct virtio_mem_resp resp;
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/* The current size of the device. */
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uint64_t plugged_size;
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/* The requested size of the device. */
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uint64_t requested_size;
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/* The device block size (for communicating with the device). */
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uint64_t device_block_size;
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/* The translated node id. NUMA_NO_NODE in case not specified. */
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int nid;
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/* Physical start address of the memory region. */
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uint64_t addr;
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/* Maximum region size in bytes. */
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uint64_t region_size;
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/* The subblock size. */
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uint64_t subblock_size;
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/* The number of subblocks per memory block. */
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uint32_t nb_sb_per_mb;
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/* Id of the first memory block of this device. */
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unsigned long first_mb_id;
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/* Id of the last memory block of this device. */
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unsigned long last_mb_id;
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/* Id of the last usable memory block of this device. */
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unsigned long last_usable_mb_id;
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/* Id of the next memory bock to prepare when needed. */
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unsigned long next_mb_id;
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/* The parent resource for all memory added via this device. */
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struct resource *parent_resource;
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/*
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* Copy of "System RAM (virtio_mem)" to be used for
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* add_memory_driver_managed().
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*/
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const char *resource_name;
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/* Summary of all memory block states. */
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unsigned long nb_mb_state[VIRTIO_MEM_MB_STATE_COUNT];
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#define VIRTIO_MEM_NB_OFFLINE_THRESHOLD 10
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/*
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* One byte state per memory block.
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*
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* Allocated via vmalloc(). When preparing new blocks, resized
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* (alloc+copy+free) when needed (crossing pages with the next mb).
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* (when crossing pages).
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*
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* With 128MB memory blocks, we have states for 512GB of memory in one
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* page.
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*/
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uint8_t *mb_state;
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/*
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* $nb_sb_per_mb bit per memory block. Handled similar to mb_state.
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*
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* With 4MB subblocks, we manage 128GB of memory in one page.
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*/
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unsigned long *sb_bitmap;
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/*
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* Mutex that protects the nb_mb_state, mb_state, and sb_bitmap.
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*
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* When this lock is held the pointers can't change, ONLINE and
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* OFFLINE blocks can't change the state and no subblocks will get
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* plugged/unplugged.
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*/
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struct mutex hotplug_mutex;
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bool hotplug_active;
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/* An error occurred we cannot handle - stop processing requests. */
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bool broken;
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/* The driver is being removed. */
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spinlock_t removal_lock;
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bool removing;
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/* Timer for retrying to plug/unplug memory. */
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struct hrtimer retry_timer;
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unsigned int retry_timer_ms;
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#define VIRTIO_MEM_RETRY_TIMER_MIN_MS 50000
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#define VIRTIO_MEM_RETRY_TIMER_MAX_MS 300000
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/* Memory notifier (online/offline events). */
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struct notifier_block memory_notifier;
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/* Next device in the list of virtio-mem devices. */
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struct list_head next;
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};
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/*
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* We have to share a single online_page callback among all virtio-mem
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* devices. We use RCU to iterate the list in the callback.
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*/
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static DEFINE_MUTEX(virtio_mem_mutex);
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static LIST_HEAD(virtio_mem_devices);
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static void virtio_mem_online_page_cb(struct page *page, unsigned int order);
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/*
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* Register a virtio-mem device so it will be considered for the online_page
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* callback.
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*/
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static int register_virtio_mem_device(struct virtio_mem *vm)
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{
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int rc = 0;
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/* First device registers the callback. */
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mutex_lock(&virtio_mem_mutex);
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if (list_empty(&virtio_mem_devices))
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rc = set_online_page_callback(&virtio_mem_online_page_cb);
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if (!rc)
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list_add_rcu(&vm->next, &virtio_mem_devices);
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mutex_unlock(&virtio_mem_mutex);
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return rc;
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}
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/*
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* Unregister a virtio-mem device so it will no longer be considered for the
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* online_page callback.
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*/
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static void unregister_virtio_mem_device(struct virtio_mem *vm)
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{
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/* Last device unregisters the callback. */
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mutex_lock(&virtio_mem_mutex);
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list_del_rcu(&vm->next);
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if (list_empty(&virtio_mem_devices))
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restore_online_page_callback(&virtio_mem_online_page_cb);
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mutex_unlock(&virtio_mem_mutex);
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synchronize_rcu();
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}
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/*
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* Calculate the memory block id of a given address.
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*/
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static unsigned long virtio_mem_phys_to_mb_id(unsigned long addr)
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{
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return addr / memory_block_size_bytes();
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}
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/*
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* Calculate the physical start address of a given memory block id.
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*/
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static unsigned long virtio_mem_mb_id_to_phys(unsigned long mb_id)
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{
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return mb_id * memory_block_size_bytes();
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}
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/*
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* Calculate the subblock id of a given address.
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*/
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static unsigned long virtio_mem_phys_to_sb_id(struct virtio_mem *vm,
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unsigned long addr)
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{
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const unsigned long mb_id = virtio_mem_phys_to_mb_id(addr);
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const unsigned long mb_addr = virtio_mem_mb_id_to_phys(mb_id);
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return (addr - mb_addr) / vm->subblock_size;
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}
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/*
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* Set the state of a memory block, taking care of the state counter.
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*/
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static void virtio_mem_mb_set_state(struct virtio_mem *vm, unsigned long mb_id,
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enum virtio_mem_mb_state state)
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{
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const unsigned long idx = mb_id - vm->first_mb_id;
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enum virtio_mem_mb_state old_state;
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old_state = vm->mb_state[idx];
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vm->mb_state[idx] = state;
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BUG_ON(vm->nb_mb_state[old_state] == 0);
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vm->nb_mb_state[old_state]--;
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vm->nb_mb_state[state]++;
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}
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/*
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* Get the state of a memory block.
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*/
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static enum virtio_mem_mb_state virtio_mem_mb_get_state(struct virtio_mem *vm,
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unsigned long mb_id)
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{
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const unsigned long idx = mb_id - vm->first_mb_id;
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return vm->mb_state[idx];
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}
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/*
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* Prepare the state array for the next memory block.
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*/
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static int virtio_mem_mb_state_prepare_next_mb(struct virtio_mem *vm)
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{
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unsigned long old_bytes = vm->next_mb_id - vm->first_mb_id + 1;
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unsigned long new_bytes = vm->next_mb_id - vm->first_mb_id + 2;
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int old_pages = PFN_UP(old_bytes);
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int new_pages = PFN_UP(new_bytes);
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uint8_t *new_mb_state;
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if (vm->mb_state && old_pages == new_pages)
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return 0;
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new_mb_state = vzalloc(new_pages * PAGE_SIZE);
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if (!new_mb_state)
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return -ENOMEM;
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mutex_lock(&vm->hotplug_mutex);
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if (vm->mb_state)
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memcpy(new_mb_state, vm->mb_state, old_pages * PAGE_SIZE);
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vfree(vm->mb_state);
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vm->mb_state = new_mb_state;
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mutex_unlock(&vm->hotplug_mutex);
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return 0;
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}
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#define virtio_mem_for_each_mb_state(_vm, _mb_id, _state) \
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for (_mb_id = _vm->first_mb_id; \
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_mb_id < _vm->next_mb_id && _vm->nb_mb_state[_state]; \
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_mb_id++) \
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if (virtio_mem_mb_get_state(_vm, _mb_id) == _state)
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#define virtio_mem_for_each_mb_state_rev(_vm, _mb_id, _state) \
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for (_mb_id = _vm->next_mb_id - 1; \
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_mb_id >= _vm->first_mb_id && _vm->nb_mb_state[_state]; \
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_mb_id--) \
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if (virtio_mem_mb_get_state(_vm, _mb_id) == _state)
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/*
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* Mark all selected subblocks plugged.
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*
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* Will not modify the state of the memory block.
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*/
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static void virtio_mem_mb_set_sb_plugged(struct virtio_mem *vm,
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unsigned long mb_id, int sb_id,
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int count)
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{
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const int bit = (mb_id - vm->first_mb_id) * vm->nb_sb_per_mb + sb_id;
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__bitmap_set(vm->sb_bitmap, bit, count);
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}
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/*
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* Mark all selected subblocks unplugged.
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*
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* Will not modify the state of the memory block.
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*/
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static void virtio_mem_mb_set_sb_unplugged(struct virtio_mem *vm,
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unsigned long mb_id, int sb_id,
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int count)
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{
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const int bit = (mb_id - vm->first_mb_id) * vm->nb_sb_per_mb + sb_id;
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__bitmap_clear(vm->sb_bitmap, bit, count);
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}
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/*
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* Test if all selected subblocks are plugged.
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*/
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static bool virtio_mem_mb_test_sb_plugged(struct virtio_mem *vm,
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unsigned long mb_id, int sb_id,
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int count)
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{
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const int bit = (mb_id - vm->first_mb_id) * vm->nb_sb_per_mb + sb_id;
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if (count == 1)
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return test_bit(bit, vm->sb_bitmap);
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/* TODO: Helper similar to bitmap_set() */
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return find_next_zero_bit(vm->sb_bitmap, bit + count, bit) >=
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bit + count;
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}
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/*
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* Test if all selected subblocks are unplugged.
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*/
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static bool virtio_mem_mb_test_sb_unplugged(struct virtio_mem *vm,
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unsigned long mb_id, int sb_id,
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int count)
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{
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const int bit = (mb_id - vm->first_mb_id) * vm->nb_sb_per_mb + sb_id;
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/* TODO: Helper similar to bitmap_set() */
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return find_next_bit(vm->sb_bitmap, bit + count, bit) >= bit + count;
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}
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/*
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* Find the first unplugged subblock. Returns vm->nb_sb_per_mb in case there is
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* none.
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*/
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static int virtio_mem_mb_first_unplugged_sb(struct virtio_mem *vm,
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unsigned long mb_id)
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{
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const int bit = (mb_id - vm->first_mb_id) * vm->nb_sb_per_mb;
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return find_next_zero_bit(vm->sb_bitmap, bit + vm->nb_sb_per_mb, bit) -
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bit;
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}
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/*
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* Prepare the subblock bitmap for the next memory block.
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*/
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static int virtio_mem_sb_bitmap_prepare_next_mb(struct virtio_mem *vm)
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{
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const unsigned long old_nb_mb = vm->next_mb_id - vm->first_mb_id;
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const unsigned long old_nb_bits = old_nb_mb * vm->nb_sb_per_mb;
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const unsigned long new_nb_bits = (old_nb_mb + 1) * vm->nb_sb_per_mb;
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int old_pages = PFN_UP(BITS_TO_LONGS(old_nb_bits) * sizeof(long));
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int new_pages = PFN_UP(BITS_TO_LONGS(new_nb_bits) * sizeof(long));
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unsigned long *new_sb_bitmap, *old_sb_bitmap;
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if (vm->sb_bitmap && old_pages == new_pages)
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return 0;
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new_sb_bitmap = vzalloc(new_pages * PAGE_SIZE);
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if (!new_sb_bitmap)
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return -ENOMEM;
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mutex_lock(&vm->hotplug_mutex);
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if (new_sb_bitmap)
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memcpy(new_sb_bitmap, vm->sb_bitmap, old_pages * PAGE_SIZE);
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old_sb_bitmap = vm->sb_bitmap;
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vm->sb_bitmap = new_sb_bitmap;
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mutex_unlock(&vm->hotplug_mutex);
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vfree(old_sb_bitmap);
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return 0;
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}
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/*
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* Try to add a memory block to Linux. This will usually only fail
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* if out of memory.
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*
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* Must not be called with the vm->hotplug_mutex held (possible deadlock with
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* onlining code).
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*
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* Will not modify the state of the memory block.
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*/
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static int virtio_mem_mb_add(struct virtio_mem *vm, unsigned long mb_id)
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{
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const uint64_t addr = virtio_mem_mb_id_to_phys(mb_id);
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int nid = vm->nid;
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if (nid == NUMA_NO_NODE)
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nid = memory_add_physaddr_to_nid(addr);
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/*
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* When force-unloading the driver and we still have memory added to
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* Linux, the resource name has to stay.
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*/
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if (!vm->resource_name) {
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vm->resource_name = kstrdup_const("System RAM (virtio_mem)",
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GFP_KERNEL);
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if (!vm->resource_name)
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return -ENOMEM;
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}
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dev_dbg(&vm->vdev->dev, "adding memory block: %lu\n", mb_id);
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return add_memory_driver_managed(nid, addr, memory_block_size_bytes(),
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vm->resource_name);
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}
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/*
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* Try to remove a memory block from Linux. Will only fail if the memory block
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* is not offline.
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*
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* Must not be called with the vm->hotplug_mutex held (possible deadlock with
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* onlining code).
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*
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* Will not modify the state of the memory block.
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*/
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static int virtio_mem_mb_remove(struct virtio_mem *vm, unsigned long mb_id)
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{
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const uint64_t addr = virtio_mem_mb_id_to_phys(mb_id);
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int nid = vm->nid;
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if (nid == NUMA_NO_NODE)
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nid = memory_add_physaddr_to_nid(addr);
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dev_dbg(&vm->vdev->dev, "removing memory block: %lu\n", mb_id);
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return remove_memory(nid, addr, memory_block_size_bytes());
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}
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/*
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* Try to offline and remove a memory block from Linux.
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*
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* Must not be called with the vm->hotplug_mutex held (possible deadlock with
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* onlining code).
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*
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* Will not modify the state of the memory block.
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*/
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static int virtio_mem_mb_offline_and_remove(struct virtio_mem *vm,
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unsigned long mb_id)
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{
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const uint64_t addr = virtio_mem_mb_id_to_phys(mb_id);
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int nid = vm->nid;
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if (nid == NUMA_NO_NODE)
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nid = memory_add_physaddr_to_nid(addr);
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dev_dbg(&vm->vdev->dev, "offlining and removing memory block: %lu\n",
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mb_id);
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return offline_and_remove_memory(nid, addr, memory_block_size_bytes());
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}
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/*
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* Trigger the workqueue so the device can perform its magic.
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*/
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static void virtio_mem_retry(struct virtio_mem *vm)
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{
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unsigned long flags;
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spin_lock_irqsave(&vm->removal_lock, flags);
|
|
if (!vm->removing)
|
|
queue_work(system_freezable_wq, &vm->wq);
|
|
spin_unlock_irqrestore(&vm->removal_lock, flags);
|
|
}
|
|
|
|
static int virtio_mem_translate_node_id(struct virtio_mem *vm, uint16_t node_id)
|
|
{
|
|
int node = NUMA_NO_NODE;
|
|
|
|
#if defined(CONFIG_ACPI_NUMA)
|
|
if (virtio_has_feature(vm->vdev, VIRTIO_MEM_F_ACPI_PXM))
|
|
node = pxm_to_node(node_id);
|
|
#endif
|
|
return node;
|
|
}
|
|
|
|
/*
|
|
* Test if a virtio-mem device overlaps with the given range. Can be called
|
|
* from (notifier) callbacks lockless.
|
|
*/
|
|
static bool virtio_mem_overlaps_range(struct virtio_mem *vm,
|
|
unsigned long start, unsigned long size)
|
|
{
|
|
unsigned long dev_start = virtio_mem_mb_id_to_phys(vm->first_mb_id);
|
|
unsigned long dev_end = virtio_mem_mb_id_to_phys(vm->last_mb_id) +
|
|
memory_block_size_bytes();
|
|
|
|
return start < dev_end && dev_start < start + size;
|
|
}
|
|
|
|
/*
|
|
* Test if a virtio-mem device owns a memory block. Can be called from
|
|
* (notifier) callbacks lockless.
|
|
*/
|
|
static bool virtio_mem_owned_mb(struct virtio_mem *vm, unsigned long mb_id)
|
|
{
|
|
return mb_id >= vm->first_mb_id && mb_id <= vm->last_mb_id;
|
|
}
|
|
|
|
static int virtio_mem_notify_going_online(struct virtio_mem *vm,
|
|
unsigned long mb_id,
|
|
enum zone_type zone)
|
|
{
|
|
switch (virtio_mem_mb_get_state(vm, mb_id)) {
|
|
case VIRTIO_MEM_MB_STATE_OFFLINE_PARTIAL:
|
|
/*
|
|
* We won't allow to online a partially plugged memory block
|
|
* to the MOVABLE zone - it would contain unmovable parts.
|
|
*/
|
|
if (zone == ZONE_MOVABLE) {
|
|
dev_warn_ratelimited(&vm->vdev->dev,
|
|
"memory block has holes, MOVABLE not supported\n");
|
|
return NOTIFY_BAD;
|
|
}
|
|
return NOTIFY_OK;
|
|
case VIRTIO_MEM_MB_STATE_OFFLINE:
|
|
return NOTIFY_OK;
|
|
default:
|
|
break;
|
|
}
|
|
dev_warn_ratelimited(&vm->vdev->dev,
|
|
"memory block onlining denied\n");
|
|
return NOTIFY_BAD;
|
|
}
|
|
|
|
static void virtio_mem_notify_offline(struct virtio_mem *vm,
|
|
unsigned long mb_id)
|
|
{
|
|
switch (virtio_mem_mb_get_state(vm, mb_id)) {
|
|
case VIRTIO_MEM_MB_STATE_ONLINE_PARTIAL:
|
|
virtio_mem_mb_set_state(vm, mb_id,
|
|
VIRTIO_MEM_MB_STATE_OFFLINE_PARTIAL);
|
|
break;
|
|
case VIRTIO_MEM_MB_STATE_ONLINE:
|
|
case VIRTIO_MEM_MB_STATE_ONLINE_MOVABLE:
|
|
virtio_mem_mb_set_state(vm, mb_id,
|
|
VIRTIO_MEM_MB_STATE_OFFLINE);
|
|
break;
|
|
default:
|
|
BUG();
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* Trigger the workqueue, maybe we can now unplug memory. Also,
|
|
* when we offline and remove a memory block, this will re-trigger
|
|
* us immediately - which is often nice because the removal of
|
|
* the memory block (e.g., memmap) might have freed up memory
|
|
* on other memory blocks we manage.
|
|
*/
|
|
virtio_mem_retry(vm);
|
|
}
|
|
|
|
static void virtio_mem_notify_online(struct virtio_mem *vm, unsigned long mb_id,
|
|
enum zone_type zone)
|
|
{
|
|
unsigned long nb_offline;
|
|
|
|
switch (virtio_mem_mb_get_state(vm, mb_id)) {
|
|
case VIRTIO_MEM_MB_STATE_OFFLINE_PARTIAL:
|
|
BUG_ON(zone == ZONE_MOVABLE);
|
|
virtio_mem_mb_set_state(vm, mb_id,
|
|
VIRTIO_MEM_MB_STATE_ONLINE_PARTIAL);
|
|
break;
|
|
case VIRTIO_MEM_MB_STATE_OFFLINE:
|
|
if (zone == ZONE_MOVABLE)
|
|
virtio_mem_mb_set_state(vm, mb_id,
|
|
VIRTIO_MEM_MB_STATE_ONLINE_MOVABLE);
|
|
else
|
|
virtio_mem_mb_set_state(vm, mb_id,
|
|
VIRTIO_MEM_MB_STATE_ONLINE);
|
|
break;
|
|
default:
|
|
BUG();
|
|
break;
|
|
}
|
|
nb_offline = vm->nb_mb_state[VIRTIO_MEM_MB_STATE_OFFLINE] +
|
|
vm->nb_mb_state[VIRTIO_MEM_MB_STATE_OFFLINE_PARTIAL];
|
|
|
|
/* see if we can add new blocks now that we onlined one block */
|
|
if (nb_offline == VIRTIO_MEM_NB_OFFLINE_THRESHOLD - 1)
|
|
virtio_mem_retry(vm);
|
|
}
|
|
|
|
static void virtio_mem_notify_going_offline(struct virtio_mem *vm,
|
|
unsigned long mb_id)
|
|
{
|
|
const unsigned long nr_pages = PFN_DOWN(vm->subblock_size);
|
|
struct page *page;
|
|
unsigned long pfn;
|
|
int sb_id, i;
|
|
|
|
for (sb_id = 0; sb_id < vm->nb_sb_per_mb; sb_id++) {
|
|
if (virtio_mem_mb_test_sb_plugged(vm, mb_id, sb_id, 1))
|
|
continue;
|
|
/*
|
|
* Drop our reference to the pages so the memory can get
|
|
* offlined and add the unplugged pages to the managed
|
|
* page counters (so offlining code can correctly subtract
|
|
* them again).
|
|
*/
|
|
pfn = PFN_DOWN(virtio_mem_mb_id_to_phys(mb_id) +
|
|
sb_id * vm->subblock_size);
|
|
adjust_managed_page_count(pfn_to_page(pfn), nr_pages);
|
|
for (i = 0; i < nr_pages; i++) {
|
|
page = pfn_to_page(pfn + i);
|
|
if (WARN_ON(!page_ref_dec_and_test(page)))
|
|
dump_page(page, "unplugged page referenced");
|
|
}
|
|
}
|
|
}
|
|
|
|
static void virtio_mem_notify_cancel_offline(struct virtio_mem *vm,
|
|
unsigned long mb_id)
|
|
{
|
|
const unsigned long nr_pages = PFN_DOWN(vm->subblock_size);
|
|
unsigned long pfn;
|
|
int sb_id, i;
|
|
|
|
for (sb_id = 0; sb_id < vm->nb_sb_per_mb; sb_id++) {
|
|
if (virtio_mem_mb_test_sb_plugged(vm, mb_id, sb_id, 1))
|
|
continue;
|
|
/*
|
|
* Get the reference we dropped when going offline and
|
|
* subtract the unplugged pages from the managed page
|
|
* counters.
|
|
*/
|
|
pfn = PFN_DOWN(virtio_mem_mb_id_to_phys(mb_id) +
|
|
sb_id * vm->subblock_size);
|
|
adjust_managed_page_count(pfn_to_page(pfn), -nr_pages);
|
|
for (i = 0; i < nr_pages; i++)
|
|
page_ref_inc(pfn_to_page(pfn + i));
|
|
}
|
|
}
|
|
|
|
/*
|
|
* This callback will either be called synchronously from add_memory() or
|
|
* asynchronously (e.g., triggered via user space). We have to be careful
|
|
* with locking when calling add_memory().
|
|
*/
|
|
static int virtio_mem_memory_notifier_cb(struct notifier_block *nb,
|
|
unsigned long action, void *arg)
|
|
{
|
|
struct virtio_mem *vm = container_of(nb, struct virtio_mem,
|
|
memory_notifier);
|
|
struct memory_notify *mhp = arg;
|
|
const unsigned long start = PFN_PHYS(mhp->start_pfn);
|
|
const unsigned long size = PFN_PHYS(mhp->nr_pages);
|
|
const unsigned long mb_id = virtio_mem_phys_to_mb_id(start);
|
|
enum zone_type zone;
|
|
int rc = NOTIFY_OK;
|
|
|
|
if (!virtio_mem_overlaps_range(vm, start, size))
|
|
return NOTIFY_DONE;
|
|
|
|
/*
|
|
* Memory is onlined/offlined in memory block granularity. We cannot
|
|
* cross virtio-mem device boundaries and memory block boundaries. Bail
|
|
* out if this ever changes.
|
|
*/
|
|
if (WARN_ON_ONCE(size != memory_block_size_bytes() ||
|
|
!IS_ALIGNED(start, memory_block_size_bytes())))
|
|
return NOTIFY_BAD;
|
|
|
|
/*
|
|
* Avoid circular locking lockdep warnings. We lock the mutex
|
|
* e.g., in MEM_GOING_ONLINE and unlock it in MEM_ONLINE. The
|
|
* blocking_notifier_call_chain() has it's own lock, which gets unlocked
|
|
* between both notifier calls and will bail out. False positive.
|
|
*/
|
|
lockdep_off();
|
|
|
|
switch (action) {
|
|
case MEM_GOING_OFFLINE:
|
|
mutex_lock(&vm->hotplug_mutex);
|
|
if (vm->removing) {
|
|
rc = notifier_from_errno(-EBUSY);
|
|
mutex_unlock(&vm->hotplug_mutex);
|
|
break;
|
|
}
|
|
vm->hotplug_active = true;
|
|
virtio_mem_notify_going_offline(vm, mb_id);
|
|
break;
|
|
case MEM_GOING_ONLINE:
|
|
mutex_lock(&vm->hotplug_mutex);
|
|
if (vm->removing) {
|
|
rc = notifier_from_errno(-EBUSY);
|
|
mutex_unlock(&vm->hotplug_mutex);
|
|
break;
|
|
}
|
|
vm->hotplug_active = true;
|
|
zone = page_zonenum(pfn_to_page(mhp->start_pfn));
|
|
rc = virtio_mem_notify_going_online(vm, mb_id, zone);
|
|
break;
|
|
case MEM_OFFLINE:
|
|
virtio_mem_notify_offline(vm, mb_id);
|
|
vm->hotplug_active = false;
|
|
mutex_unlock(&vm->hotplug_mutex);
|
|
break;
|
|
case MEM_ONLINE:
|
|
zone = page_zonenum(pfn_to_page(mhp->start_pfn));
|
|
virtio_mem_notify_online(vm, mb_id, zone);
|
|
vm->hotplug_active = false;
|
|
mutex_unlock(&vm->hotplug_mutex);
|
|
break;
|
|
case MEM_CANCEL_OFFLINE:
|
|
if (!vm->hotplug_active)
|
|
break;
|
|
virtio_mem_notify_cancel_offline(vm, mb_id);
|
|
vm->hotplug_active = false;
|
|
mutex_unlock(&vm->hotplug_mutex);
|
|
break;
|
|
case MEM_CANCEL_ONLINE:
|
|
if (!vm->hotplug_active)
|
|
break;
|
|
vm->hotplug_active = false;
|
|
mutex_unlock(&vm->hotplug_mutex);
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
|
|
lockdep_on();
|
|
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
* Set a range of pages PG_offline. Remember pages that were never onlined
|
|
* (via generic_online_page()) using PageDirty().
|
|
*/
|
|
static void virtio_mem_set_fake_offline(unsigned long pfn,
|
|
unsigned int nr_pages, bool onlined)
|
|
{
|
|
for (; nr_pages--; pfn++) {
|
|
struct page *page = pfn_to_page(pfn);
|
|
|
|
__SetPageOffline(page);
|
|
if (!onlined) {
|
|
SetPageDirty(page);
|
|
/* FIXME: remove after cleanups */
|
|
ClearPageReserved(page);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Clear PG_offline from a range of pages. If the pages were never onlined,
|
|
* (via generic_online_page()), clear PageDirty().
|
|
*/
|
|
static void virtio_mem_clear_fake_offline(unsigned long pfn,
|
|
unsigned int nr_pages, bool onlined)
|
|
{
|
|
for (; nr_pages--; pfn++) {
|
|
struct page *page = pfn_to_page(pfn);
|
|
|
|
__ClearPageOffline(page);
|
|
if (!onlined)
|
|
ClearPageDirty(page);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Release a range of fake-offline pages to the buddy, effectively
|
|
* fake-onlining them.
|
|
*/
|
|
static void virtio_mem_fake_online(unsigned long pfn, unsigned int nr_pages)
|
|
{
|
|
const int order = MAX_ORDER - 1;
|
|
int i;
|
|
|
|
/*
|
|
* We are always called with subblock granularity, which is at least
|
|
* aligned to MAX_ORDER - 1.
|
|
*/
|
|
for (i = 0; i < nr_pages; i += 1 << order) {
|
|
struct page *page = pfn_to_page(pfn + i);
|
|
|
|
/*
|
|
* If the page is PageDirty(), it was kept fake-offline when
|
|
* onlining the memory block. Otherwise, it was allocated
|
|
* using alloc_contig_range(). All pages in a subblock are
|
|
* alike.
|
|
*/
|
|
if (PageDirty(page)) {
|
|
virtio_mem_clear_fake_offline(pfn + i, 1 << order,
|
|
false);
|
|
generic_online_page(page, order);
|
|
} else {
|
|
virtio_mem_clear_fake_offline(pfn + i, 1 << order,
|
|
true);
|
|
free_contig_range(pfn + i, 1 << order);
|
|
adjust_managed_page_count(page, 1 << order);
|
|
}
|
|
}
|
|
}
|
|
|
|
static void virtio_mem_online_page_cb(struct page *page, unsigned int order)
|
|
{
|
|
const unsigned long addr = page_to_phys(page);
|
|
const unsigned long mb_id = virtio_mem_phys_to_mb_id(addr);
|
|
struct virtio_mem *vm;
|
|
int sb_id;
|
|
|
|
/*
|
|
* We exploit here that subblocks have at least MAX_ORDER - 1
|
|
* size/alignment and that this callback is is called with such a
|
|
* size/alignment. So we cannot cross subblocks and therefore
|
|
* also not memory blocks.
|
|
*/
|
|
rcu_read_lock();
|
|
list_for_each_entry_rcu(vm, &virtio_mem_devices, next) {
|
|
if (!virtio_mem_owned_mb(vm, mb_id))
|
|
continue;
|
|
|
|
sb_id = virtio_mem_phys_to_sb_id(vm, addr);
|
|
/*
|
|
* If plugged, online the pages, otherwise, set them fake
|
|
* offline (PageOffline).
|
|
*/
|
|
if (virtio_mem_mb_test_sb_plugged(vm, mb_id, sb_id, 1))
|
|
generic_online_page(page, order);
|
|
else
|
|
virtio_mem_set_fake_offline(PFN_DOWN(addr), 1 << order,
|
|
false);
|
|
rcu_read_unlock();
|
|
return;
|
|
}
|
|
rcu_read_unlock();
|
|
|
|
/* not virtio-mem memory, but e.g., a DIMM. online it */
|
|
generic_online_page(page, order);
|
|
}
|
|
|
|
static uint64_t virtio_mem_send_request(struct virtio_mem *vm,
|
|
const struct virtio_mem_req *req)
|
|
{
|
|
struct scatterlist *sgs[2], sg_req, sg_resp;
|
|
unsigned int len;
|
|
int rc;
|
|
|
|
/* don't use the request residing on the stack (vaddr) */
|
|
vm->req = *req;
|
|
|
|
/* out: buffer for request */
|
|
sg_init_one(&sg_req, &vm->req, sizeof(vm->req));
|
|
sgs[0] = &sg_req;
|
|
|
|
/* in: buffer for response */
|
|
sg_init_one(&sg_resp, &vm->resp, sizeof(vm->resp));
|
|
sgs[1] = &sg_resp;
|
|
|
|
rc = virtqueue_add_sgs(vm->vq, sgs, 1, 1, vm, GFP_KERNEL);
|
|
if (rc < 0)
|
|
return rc;
|
|
|
|
virtqueue_kick(vm->vq);
|
|
|
|
/* wait for a response */
|
|
wait_event(vm->host_resp, virtqueue_get_buf(vm->vq, &len));
|
|
|
|
return virtio16_to_cpu(vm->vdev, vm->resp.type);
|
|
}
|
|
|
|
static int virtio_mem_send_plug_request(struct virtio_mem *vm, uint64_t addr,
|
|
uint64_t size)
|
|
{
|
|
const uint64_t nb_vm_blocks = size / vm->device_block_size;
|
|
const struct virtio_mem_req req = {
|
|
.type = cpu_to_virtio16(vm->vdev, VIRTIO_MEM_REQ_PLUG),
|
|
.u.plug.addr = cpu_to_virtio64(vm->vdev, addr),
|
|
.u.plug.nb_blocks = cpu_to_virtio16(vm->vdev, nb_vm_blocks),
|
|
};
|
|
|
|
if (atomic_read(&vm->config_changed))
|
|
return -EAGAIN;
|
|
|
|
switch (virtio_mem_send_request(vm, &req)) {
|
|
case VIRTIO_MEM_RESP_ACK:
|
|
vm->plugged_size += size;
|
|
return 0;
|
|
case VIRTIO_MEM_RESP_NACK:
|
|
return -EAGAIN;
|
|
case VIRTIO_MEM_RESP_BUSY:
|
|
return -ETXTBSY;
|
|
case VIRTIO_MEM_RESP_ERROR:
|
|
return -EINVAL;
|
|
default:
|
|
return -ENOMEM;
|
|
}
|
|
}
|
|
|
|
static int virtio_mem_send_unplug_request(struct virtio_mem *vm, uint64_t addr,
|
|
uint64_t size)
|
|
{
|
|
const uint64_t nb_vm_blocks = size / vm->device_block_size;
|
|
const struct virtio_mem_req req = {
|
|
.type = cpu_to_virtio16(vm->vdev, VIRTIO_MEM_REQ_UNPLUG),
|
|
.u.unplug.addr = cpu_to_virtio64(vm->vdev, addr),
|
|
.u.unplug.nb_blocks = cpu_to_virtio16(vm->vdev, nb_vm_blocks),
|
|
};
|
|
|
|
if (atomic_read(&vm->config_changed))
|
|
return -EAGAIN;
|
|
|
|
switch (virtio_mem_send_request(vm, &req)) {
|
|
case VIRTIO_MEM_RESP_ACK:
|
|
vm->plugged_size -= size;
|
|
return 0;
|
|
case VIRTIO_MEM_RESP_BUSY:
|
|
return -ETXTBSY;
|
|
case VIRTIO_MEM_RESP_ERROR:
|
|
return -EINVAL;
|
|
default:
|
|
return -ENOMEM;
|
|
}
|
|
}
|
|
|
|
static int virtio_mem_send_unplug_all_request(struct virtio_mem *vm)
|
|
{
|
|
const struct virtio_mem_req req = {
|
|
.type = cpu_to_virtio16(vm->vdev, VIRTIO_MEM_REQ_UNPLUG_ALL),
|
|
};
|
|
|
|
switch (virtio_mem_send_request(vm, &req)) {
|
|
case VIRTIO_MEM_RESP_ACK:
|
|
vm->unplug_all_required = false;
|
|
vm->plugged_size = 0;
|
|
/* usable region might have shrunk */
|
|
atomic_set(&vm->config_changed, 1);
|
|
return 0;
|
|
case VIRTIO_MEM_RESP_BUSY:
|
|
return -ETXTBSY;
|
|
default:
|
|
return -ENOMEM;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Plug selected subblocks. Updates the plugged state, but not the state
|
|
* of the memory block.
|
|
*/
|
|
static int virtio_mem_mb_plug_sb(struct virtio_mem *vm, unsigned long mb_id,
|
|
int sb_id, int count)
|
|
{
|
|
const uint64_t addr = virtio_mem_mb_id_to_phys(mb_id) +
|
|
sb_id * vm->subblock_size;
|
|
const uint64_t size = count * vm->subblock_size;
|
|
int rc;
|
|
|
|
dev_dbg(&vm->vdev->dev, "plugging memory block: %lu : %i - %i\n", mb_id,
|
|
sb_id, sb_id + count - 1);
|
|
|
|
rc = virtio_mem_send_plug_request(vm, addr, size);
|
|
if (!rc)
|
|
virtio_mem_mb_set_sb_plugged(vm, mb_id, sb_id, count);
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
* Unplug selected subblocks. Updates the plugged state, but not the state
|
|
* of the memory block.
|
|
*/
|
|
static int virtio_mem_mb_unplug_sb(struct virtio_mem *vm, unsigned long mb_id,
|
|
int sb_id, int count)
|
|
{
|
|
const uint64_t addr = virtio_mem_mb_id_to_phys(mb_id) +
|
|
sb_id * vm->subblock_size;
|
|
const uint64_t size = count * vm->subblock_size;
|
|
int rc;
|
|
|
|
dev_dbg(&vm->vdev->dev, "unplugging memory block: %lu : %i - %i\n",
|
|
mb_id, sb_id, sb_id + count - 1);
|
|
|
|
rc = virtio_mem_send_unplug_request(vm, addr, size);
|
|
if (!rc)
|
|
virtio_mem_mb_set_sb_unplugged(vm, mb_id, sb_id, count);
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
* Unplug the desired number of plugged subblocks of a offline or not-added
|
|
* memory block. Will fail if any subblock cannot get unplugged (instead of
|
|
* skipping it).
|
|
*
|
|
* Will not modify the state of the memory block.
|
|
*
|
|
* Note: can fail after some subblocks were unplugged.
|
|
*/
|
|
static int virtio_mem_mb_unplug_any_sb(struct virtio_mem *vm,
|
|
unsigned long mb_id, uint64_t *nb_sb)
|
|
{
|
|
int sb_id, count;
|
|
int rc;
|
|
|
|
sb_id = vm->nb_sb_per_mb - 1;
|
|
while (*nb_sb) {
|
|
/* Find the next candidate subblock */
|
|
while (sb_id >= 0 &&
|
|
virtio_mem_mb_test_sb_unplugged(vm, mb_id, sb_id, 1))
|
|
sb_id--;
|
|
if (sb_id < 0)
|
|
break;
|
|
/* Try to unplug multiple subblocks at a time */
|
|
count = 1;
|
|
while (count < *nb_sb && sb_id > 0 &&
|
|
virtio_mem_mb_test_sb_plugged(vm, mb_id, sb_id - 1, 1)) {
|
|
count++;
|
|
sb_id--;
|
|
}
|
|
|
|
rc = virtio_mem_mb_unplug_sb(vm, mb_id, sb_id, count);
|
|
if (rc)
|
|
return rc;
|
|
*nb_sb -= count;
|
|
sb_id--;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Unplug all plugged subblocks of an offline or not-added memory block.
|
|
*
|
|
* Will not modify the state of the memory block.
|
|
*
|
|
* Note: can fail after some subblocks were unplugged.
|
|
*/
|
|
static int virtio_mem_mb_unplug(struct virtio_mem *vm, unsigned long mb_id)
|
|
{
|
|
uint64_t nb_sb = vm->nb_sb_per_mb;
|
|
|
|
return virtio_mem_mb_unplug_any_sb(vm, mb_id, &nb_sb);
|
|
}
|
|
|
|
/*
|
|
* Prepare tracking data for the next memory block.
|
|
*/
|
|
static int virtio_mem_prepare_next_mb(struct virtio_mem *vm,
|
|
unsigned long *mb_id)
|
|
{
|
|
int rc;
|
|
|
|
if (vm->next_mb_id > vm->last_usable_mb_id)
|
|
return -ENOSPC;
|
|
|
|
/* Resize the state array if required. */
|
|
rc = virtio_mem_mb_state_prepare_next_mb(vm);
|
|
if (rc)
|
|
return rc;
|
|
|
|
/* Resize the subblock bitmap if required. */
|
|
rc = virtio_mem_sb_bitmap_prepare_next_mb(vm);
|
|
if (rc)
|
|
return rc;
|
|
|
|
vm->nb_mb_state[VIRTIO_MEM_MB_STATE_UNUSED]++;
|
|
*mb_id = vm->next_mb_id++;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Don't add too many blocks that are not onlined yet to avoid running OOM.
|
|
*/
|
|
static bool virtio_mem_too_many_mb_offline(struct virtio_mem *vm)
|
|
{
|
|
unsigned long nb_offline;
|
|
|
|
nb_offline = vm->nb_mb_state[VIRTIO_MEM_MB_STATE_OFFLINE] +
|
|
vm->nb_mb_state[VIRTIO_MEM_MB_STATE_OFFLINE_PARTIAL];
|
|
return nb_offline >= VIRTIO_MEM_NB_OFFLINE_THRESHOLD;
|
|
}
|
|
|
|
/*
|
|
* Try to plug the desired number of subblocks and add the memory block
|
|
* to Linux.
|
|
*
|
|
* Will modify the state of the memory block.
|
|
*/
|
|
static int virtio_mem_mb_plug_and_add(struct virtio_mem *vm,
|
|
unsigned long mb_id,
|
|
uint64_t *nb_sb)
|
|
{
|
|
const int count = min_t(int, *nb_sb, vm->nb_sb_per_mb);
|
|
int rc, rc2;
|
|
|
|
if (WARN_ON_ONCE(!count))
|
|
return -EINVAL;
|
|
|
|
/*
|
|
* Plug the requested number of subblocks before adding it to linux,
|
|
* so that onlining will directly online all plugged subblocks.
|
|
*/
|
|
rc = virtio_mem_mb_plug_sb(vm, mb_id, 0, count);
|
|
if (rc)
|
|
return rc;
|
|
|
|
/*
|
|
* Mark the block properly offline before adding it to Linux,
|
|
* so the memory notifiers will find the block in the right state.
|
|
*/
|
|
if (count == vm->nb_sb_per_mb)
|
|
virtio_mem_mb_set_state(vm, mb_id,
|
|
VIRTIO_MEM_MB_STATE_OFFLINE);
|
|
else
|
|
virtio_mem_mb_set_state(vm, mb_id,
|
|
VIRTIO_MEM_MB_STATE_OFFLINE_PARTIAL);
|
|
|
|
/* Add the memory block to linux - if that fails, try to unplug. */
|
|
rc = virtio_mem_mb_add(vm, mb_id);
|
|
if (rc) {
|
|
enum virtio_mem_mb_state new_state = VIRTIO_MEM_MB_STATE_UNUSED;
|
|
|
|
dev_err(&vm->vdev->dev,
|
|
"adding memory block %lu failed with %d\n", mb_id, rc);
|
|
rc2 = virtio_mem_mb_unplug_sb(vm, mb_id, 0, count);
|
|
|
|
/*
|
|
* TODO: Linux MM does not properly clean up yet in all cases
|
|
* where adding of memory failed - especially on -ENOMEM.
|
|
*/
|
|
if (rc2)
|
|
new_state = VIRTIO_MEM_MB_STATE_PLUGGED;
|
|
virtio_mem_mb_set_state(vm, mb_id, new_state);
|
|
return rc;
|
|
}
|
|
|
|
*nb_sb -= count;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Try to plug the desired number of subblocks of a memory block that
|
|
* is already added to Linux.
|
|
*
|
|
* Will modify the state of the memory block.
|
|
*
|
|
* Note: Can fail after some subblocks were successfully plugged.
|
|
*/
|
|
static int virtio_mem_mb_plug_any_sb(struct virtio_mem *vm, unsigned long mb_id,
|
|
uint64_t *nb_sb, bool online)
|
|
{
|
|
unsigned long pfn, nr_pages;
|
|
int sb_id, count;
|
|
int rc;
|
|
|
|
if (WARN_ON_ONCE(!*nb_sb))
|
|
return -EINVAL;
|
|
|
|
while (*nb_sb) {
|
|
sb_id = virtio_mem_mb_first_unplugged_sb(vm, mb_id);
|
|
if (sb_id >= vm->nb_sb_per_mb)
|
|
break;
|
|
count = 1;
|
|
while (count < *nb_sb &&
|
|
sb_id + count < vm->nb_sb_per_mb &&
|
|
!virtio_mem_mb_test_sb_plugged(vm, mb_id, sb_id + count,
|
|
1))
|
|
count++;
|
|
|
|
rc = virtio_mem_mb_plug_sb(vm, mb_id, sb_id, count);
|
|
if (rc)
|
|
return rc;
|
|
*nb_sb -= count;
|
|
if (!online)
|
|
continue;
|
|
|
|
/* fake-online the pages if the memory block is online */
|
|
pfn = PFN_DOWN(virtio_mem_mb_id_to_phys(mb_id) +
|
|
sb_id * vm->subblock_size);
|
|
nr_pages = PFN_DOWN(count * vm->subblock_size);
|
|
virtio_mem_fake_online(pfn, nr_pages);
|
|
}
|
|
|
|
if (virtio_mem_mb_test_sb_plugged(vm, mb_id, 0, vm->nb_sb_per_mb)) {
|
|
if (online)
|
|
virtio_mem_mb_set_state(vm, mb_id,
|
|
VIRTIO_MEM_MB_STATE_ONLINE);
|
|
else
|
|
virtio_mem_mb_set_state(vm, mb_id,
|
|
VIRTIO_MEM_MB_STATE_OFFLINE);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Try to plug the requested amount of memory.
|
|
*/
|
|
static int virtio_mem_plug_request(struct virtio_mem *vm, uint64_t diff)
|
|
{
|
|
uint64_t nb_sb = diff / vm->subblock_size;
|
|
unsigned long mb_id;
|
|
int rc;
|
|
|
|
if (!nb_sb)
|
|
return 0;
|
|
|
|
/* Don't race with onlining/offlining */
|
|
mutex_lock(&vm->hotplug_mutex);
|
|
|
|
/* Try to plug subblocks of partially plugged online blocks. */
|
|
virtio_mem_for_each_mb_state(vm, mb_id,
|
|
VIRTIO_MEM_MB_STATE_ONLINE_PARTIAL) {
|
|
rc = virtio_mem_mb_plug_any_sb(vm, mb_id, &nb_sb, true);
|
|
if (rc || !nb_sb)
|
|
goto out_unlock;
|
|
cond_resched();
|
|
}
|
|
|
|
/* Try to plug subblocks of partially plugged offline blocks. */
|
|
virtio_mem_for_each_mb_state(vm, mb_id,
|
|
VIRTIO_MEM_MB_STATE_OFFLINE_PARTIAL) {
|
|
rc = virtio_mem_mb_plug_any_sb(vm, mb_id, &nb_sb, false);
|
|
if (rc || !nb_sb)
|
|
goto out_unlock;
|
|
cond_resched();
|
|
}
|
|
|
|
/*
|
|
* We won't be working on online/offline memory blocks from this point,
|
|
* so we can't race with memory onlining/offlining. Drop the mutex.
|
|
*/
|
|
mutex_unlock(&vm->hotplug_mutex);
|
|
|
|
/* Try to plug and add unused blocks */
|
|
virtio_mem_for_each_mb_state(vm, mb_id, VIRTIO_MEM_MB_STATE_UNUSED) {
|
|
if (virtio_mem_too_many_mb_offline(vm))
|
|
return -ENOSPC;
|
|
|
|
rc = virtio_mem_mb_plug_and_add(vm, mb_id, &nb_sb);
|
|
if (rc || !nb_sb)
|
|
return rc;
|
|
cond_resched();
|
|
}
|
|
|
|
/* Try to prepare, plug and add new blocks */
|
|
while (nb_sb) {
|
|
if (virtio_mem_too_many_mb_offline(vm))
|
|
return -ENOSPC;
|
|
|
|
rc = virtio_mem_prepare_next_mb(vm, &mb_id);
|
|
if (rc)
|
|
return rc;
|
|
rc = virtio_mem_mb_plug_and_add(vm, mb_id, &nb_sb);
|
|
if (rc)
|
|
return rc;
|
|
cond_resched();
|
|
}
|
|
|
|
return 0;
|
|
out_unlock:
|
|
mutex_unlock(&vm->hotplug_mutex);
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
* Unplug the desired number of plugged subblocks of an offline memory block.
|
|
* Will fail if any subblock cannot get unplugged (instead of skipping it).
|
|
*
|
|
* Will modify the state of the memory block. Might temporarily drop the
|
|
* hotplug_mutex.
|
|
*
|
|
* Note: Can fail after some subblocks were successfully unplugged.
|
|
*/
|
|
static int virtio_mem_mb_unplug_any_sb_offline(struct virtio_mem *vm,
|
|
unsigned long mb_id,
|
|
uint64_t *nb_sb)
|
|
{
|
|
int rc;
|
|
|
|
rc = virtio_mem_mb_unplug_any_sb(vm, mb_id, nb_sb);
|
|
|
|
/* some subblocks might have been unplugged even on failure */
|
|
if (!virtio_mem_mb_test_sb_plugged(vm, mb_id, 0, vm->nb_sb_per_mb))
|
|
virtio_mem_mb_set_state(vm, mb_id,
|
|
VIRTIO_MEM_MB_STATE_OFFLINE_PARTIAL);
|
|
if (rc)
|
|
return rc;
|
|
|
|
if (virtio_mem_mb_test_sb_unplugged(vm, mb_id, 0, vm->nb_sb_per_mb)) {
|
|
/*
|
|
* Remove the block from Linux - this should never fail.
|
|
* Hinder the block from getting onlined by marking it
|
|
* unplugged. Temporarily drop the mutex, so
|
|
* any pending GOING_ONLINE requests can be serviced/rejected.
|
|
*/
|
|
virtio_mem_mb_set_state(vm, mb_id,
|
|
VIRTIO_MEM_MB_STATE_UNUSED);
|
|
|
|
mutex_unlock(&vm->hotplug_mutex);
|
|
rc = virtio_mem_mb_remove(vm, mb_id);
|
|
BUG_ON(rc);
|
|
mutex_lock(&vm->hotplug_mutex);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Unplug the given plugged subblocks of an online memory block.
|
|
*
|
|
* Will modify the state of the memory block.
|
|
*/
|
|
static int virtio_mem_mb_unplug_sb_online(struct virtio_mem *vm,
|
|
unsigned long mb_id, int sb_id,
|
|
int count)
|
|
{
|
|
const unsigned long nr_pages = PFN_DOWN(vm->subblock_size) * count;
|
|
unsigned long start_pfn;
|
|
int rc;
|
|
|
|
start_pfn = PFN_DOWN(virtio_mem_mb_id_to_phys(mb_id) +
|
|
sb_id * vm->subblock_size);
|
|
rc = alloc_contig_range(start_pfn, start_pfn + nr_pages,
|
|
MIGRATE_MOVABLE, GFP_KERNEL);
|
|
if (rc == -ENOMEM)
|
|
/* whoops, out of memory */
|
|
return rc;
|
|
if (rc)
|
|
return -EBUSY;
|
|
|
|
/* Mark it as fake-offline before unplugging it */
|
|
virtio_mem_set_fake_offline(start_pfn, nr_pages, true);
|
|
adjust_managed_page_count(pfn_to_page(start_pfn), -nr_pages);
|
|
|
|
/* Try to unplug the allocated memory */
|
|
rc = virtio_mem_mb_unplug_sb(vm, mb_id, sb_id, count);
|
|
if (rc) {
|
|
/* Return the memory to the buddy. */
|
|
virtio_mem_fake_online(start_pfn, nr_pages);
|
|
return rc;
|
|
}
|
|
|
|
virtio_mem_mb_set_state(vm, mb_id,
|
|
VIRTIO_MEM_MB_STATE_ONLINE_PARTIAL);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Unplug the desired number of plugged subblocks of an online memory block.
|
|
* Will skip subblock that are busy.
|
|
*
|
|
* Will modify the state of the memory block. Might temporarily drop the
|
|
* hotplug_mutex.
|
|
*
|
|
* Note: Can fail after some subblocks were successfully unplugged. Can
|
|
* return 0 even if subblocks were busy and could not get unplugged.
|
|
*/
|
|
static int virtio_mem_mb_unplug_any_sb_online(struct virtio_mem *vm,
|
|
unsigned long mb_id,
|
|
uint64_t *nb_sb)
|
|
{
|
|
int rc, sb_id;
|
|
|
|
/* If possible, try to unplug the complete block in one shot. */
|
|
if (*nb_sb >= vm->nb_sb_per_mb &&
|
|
virtio_mem_mb_test_sb_plugged(vm, mb_id, 0, vm->nb_sb_per_mb)) {
|
|
rc = virtio_mem_mb_unplug_sb_online(vm, mb_id, 0,
|
|
vm->nb_sb_per_mb);
|
|
if (!rc) {
|
|
*nb_sb -= vm->nb_sb_per_mb;
|
|
goto unplugged;
|
|
} else if (rc != -EBUSY)
|
|
return rc;
|
|
}
|
|
|
|
/* Fallback to single subblocks. */
|
|
for (sb_id = vm->nb_sb_per_mb - 1; sb_id >= 0 && *nb_sb; sb_id--) {
|
|
/* Find the next candidate subblock */
|
|
while (sb_id >= 0 &&
|
|
!virtio_mem_mb_test_sb_plugged(vm, mb_id, sb_id, 1))
|
|
sb_id--;
|
|
if (sb_id < 0)
|
|
break;
|
|
|
|
rc = virtio_mem_mb_unplug_sb_online(vm, mb_id, sb_id, 1);
|
|
if (rc == -EBUSY)
|
|
continue;
|
|
else if (rc)
|
|
return rc;
|
|
*nb_sb -= 1;
|
|
}
|
|
|
|
unplugged:
|
|
/*
|
|
* Once all subblocks of a memory block were unplugged, offline and
|
|
* remove it. This will usually not fail, as no memory is in use
|
|
* anymore - however some other notifiers might NACK the request.
|
|
*/
|
|
if (virtio_mem_mb_test_sb_unplugged(vm, mb_id, 0, vm->nb_sb_per_mb)) {
|
|
mutex_unlock(&vm->hotplug_mutex);
|
|
rc = virtio_mem_mb_offline_and_remove(vm, mb_id);
|
|
mutex_lock(&vm->hotplug_mutex);
|
|
if (!rc)
|
|
virtio_mem_mb_set_state(vm, mb_id,
|
|
VIRTIO_MEM_MB_STATE_UNUSED);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Try to unplug the requested amount of memory.
|
|
*/
|
|
static int virtio_mem_unplug_request(struct virtio_mem *vm, uint64_t diff)
|
|
{
|
|
uint64_t nb_sb = diff / vm->subblock_size;
|
|
unsigned long mb_id;
|
|
int rc;
|
|
|
|
if (!nb_sb)
|
|
return 0;
|
|
|
|
/*
|
|
* We'll drop the mutex a couple of times when it is safe to do so.
|
|
* This might result in some blocks switching the state (online/offline)
|
|
* and we could miss them in this run - we will retry again later.
|
|
*/
|
|
mutex_lock(&vm->hotplug_mutex);
|
|
|
|
/* Try to unplug subblocks of partially plugged offline blocks. */
|
|
virtio_mem_for_each_mb_state_rev(vm, mb_id,
|
|
VIRTIO_MEM_MB_STATE_OFFLINE_PARTIAL) {
|
|
rc = virtio_mem_mb_unplug_any_sb_offline(vm, mb_id,
|
|
&nb_sb);
|
|
if (rc || !nb_sb)
|
|
goto out_unlock;
|
|
cond_resched();
|
|
}
|
|
|
|
/* Try to unplug subblocks of plugged offline blocks. */
|
|
virtio_mem_for_each_mb_state_rev(vm, mb_id,
|
|
VIRTIO_MEM_MB_STATE_OFFLINE) {
|
|
rc = virtio_mem_mb_unplug_any_sb_offline(vm, mb_id,
|
|
&nb_sb);
|
|
if (rc || !nb_sb)
|
|
goto out_unlock;
|
|
cond_resched();
|
|
}
|
|
|
|
if (!unplug_online) {
|
|
mutex_unlock(&vm->hotplug_mutex);
|
|
return 0;
|
|
}
|
|
|
|
/* Try to unplug subblocks of partially plugged online blocks. */
|
|
virtio_mem_for_each_mb_state_rev(vm, mb_id,
|
|
VIRTIO_MEM_MB_STATE_ONLINE_PARTIAL) {
|
|
rc = virtio_mem_mb_unplug_any_sb_online(vm, mb_id,
|
|
&nb_sb);
|
|
if (rc || !nb_sb)
|
|
goto out_unlock;
|
|
mutex_unlock(&vm->hotplug_mutex);
|
|
cond_resched();
|
|
mutex_lock(&vm->hotplug_mutex);
|
|
}
|
|
|
|
/* Try to unplug subblocks of plugged online blocks. */
|
|
virtio_mem_for_each_mb_state_rev(vm, mb_id,
|
|
VIRTIO_MEM_MB_STATE_ONLINE) {
|
|
rc = virtio_mem_mb_unplug_any_sb_online(vm, mb_id,
|
|
&nb_sb);
|
|
if (rc || !nb_sb)
|
|
goto out_unlock;
|
|
mutex_unlock(&vm->hotplug_mutex);
|
|
cond_resched();
|
|
mutex_lock(&vm->hotplug_mutex);
|
|
}
|
|
|
|
mutex_unlock(&vm->hotplug_mutex);
|
|
return nb_sb ? -EBUSY : 0;
|
|
out_unlock:
|
|
mutex_unlock(&vm->hotplug_mutex);
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
* Try to unplug all blocks that couldn't be unplugged before, for example,
|
|
* because the hypervisor was busy.
|
|
*/
|
|
static int virtio_mem_unplug_pending_mb(struct virtio_mem *vm)
|
|
{
|
|
unsigned long mb_id;
|
|
int rc;
|
|
|
|
virtio_mem_for_each_mb_state(vm, mb_id, VIRTIO_MEM_MB_STATE_PLUGGED) {
|
|
rc = virtio_mem_mb_unplug(vm, mb_id);
|
|
if (rc)
|
|
return rc;
|
|
virtio_mem_mb_set_state(vm, mb_id, VIRTIO_MEM_MB_STATE_UNUSED);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Update all parts of the config that could have changed.
|
|
*/
|
|
static void virtio_mem_refresh_config(struct virtio_mem *vm)
|
|
{
|
|
const uint64_t phys_limit = 1UL << MAX_PHYSMEM_BITS;
|
|
uint64_t new_plugged_size, usable_region_size, end_addr;
|
|
|
|
/* the plugged_size is just a reflection of what _we_ did previously */
|
|
virtio_cread_le(vm->vdev, struct virtio_mem_config, plugged_size,
|
|
&new_plugged_size);
|
|
if (WARN_ON_ONCE(new_plugged_size != vm->plugged_size))
|
|
vm->plugged_size = new_plugged_size;
|
|
|
|
/* calculate the last usable memory block id */
|
|
virtio_cread_le(vm->vdev, struct virtio_mem_config,
|
|
usable_region_size, &usable_region_size);
|
|
end_addr = vm->addr + usable_region_size;
|
|
end_addr = min(end_addr, phys_limit);
|
|
vm->last_usable_mb_id = virtio_mem_phys_to_mb_id(end_addr) - 1;
|
|
|
|
/* see if there is a request to change the size */
|
|
virtio_cread_le(vm->vdev, struct virtio_mem_config, requested_size,
|
|
&vm->requested_size);
|
|
|
|
dev_info(&vm->vdev->dev, "plugged size: 0x%llx", vm->plugged_size);
|
|
dev_info(&vm->vdev->dev, "requested size: 0x%llx", vm->requested_size);
|
|
}
|
|
|
|
/*
|
|
* Workqueue function for handling plug/unplug requests and config updates.
|
|
*/
|
|
static void virtio_mem_run_wq(struct work_struct *work)
|
|
{
|
|
struct virtio_mem *vm = container_of(work, struct virtio_mem, wq);
|
|
uint64_t diff;
|
|
int rc;
|
|
|
|
hrtimer_cancel(&vm->retry_timer);
|
|
|
|
if (vm->broken)
|
|
return;
|
|
|
|
retry:
|
|
rc = 0;
|
|
|
|
/* Make sure we start with a clean state if there are leftovers. */
|
|
if (unlikely(vm->unplug_all_required))
|
|
rc = virtio_mem_send_unplug_all_request(vm);
|
|
|
|
if (atomic_read(&vm->config_changed)) {
|
|
atomic_set(&vm->config_changed, 0);
|
|
virtio_mem_refresh_config(vm);
|
|
}
|
|
|
|
/* Unplug any leftovers from previous runs */
|
|
if (!rc)
|
|
rc = virtio_mem_unplug_pending_mb(vm);
|
|
|
|
if (!rc && vm->requested_size != vm->plugged_size) {
|
|
if (vm->requested_size > vm->plugged_size) {
|
|
diff = vm->requested_size - vm->plugged_size;
|
|
rc = virtio_mem_plug_request(vm, diff);
|
|
} else {
|
|
diff = vm->plugged_size - vm->requested_size;
|
|
rc = virtio_mem_unplug_request(vm, diff);
|
|
}
|
|
}
|
|
|
|
switch (rc) {
|
|
case 0:
|
|
vm->retry_timer_ms = VIRTIO_MEM_RETRY_TIMER_MIN_MS;
|
|
break;
|
|
case -ENOSPC:
|
|
/*
|
|
* We cannot add any more memory (alignment, physical limit)
|
|
* or we have too many offline memory blocks.
|
|
*/
|
|
break;
|
|
case -ETXTBSY:
|
|
/*
|
|
* The hypervisor cannot process our request right now
|
|
* (e.g., out of memory, migrating);
|
|
*/
|
|
case -EBUSY:
|
|
/*
|
|
* We cannot free up any memory to unplug it (all plugged memory
|
|
* is busy).
|
|
*/
|
|
case -ENOMEM:
|
|
/* Out of memory, try again later. */
|
|
hrtimer_start(&vm->retry_timer, ms_to_ktime(vm->retry_timer_ms),
|
|
HRTIMER_MODE_REL);
|
|
break;
|
|
case -EAGAIN:
|
|
/* Retry immediately (e.g., the config changed). */
|
|
goto retry;
|
|
default:
|
|
/* Unknown error, mark as broken */
|
|
dev_err(&vm->vdev->dev,
|
|
"unknown error, marking device broken: %d\n", rc);
|
|
vm->broken = true;
|
|
}
|
|
}
|
|
|
|
static enum hrtimer_restart virtio_mem_timer_expired(struct hrtimer *timer)
|
|
{
|
|
struct virtio_mem *vm = container_of(timer, struct virtio_mem,
|
|
retry_timer);
|
|
|
|
virtio_mem_retry(vm);
|
|
vm->retry_timer_ms = min_t(unsigned int, vm->retry_timer_ms * 2,
|
|
VIRTIO_MEM_RETRY_TIMER_MAX_MS);
|
|
return HRTIMER_NORESTART;
|
|
}
|
|
|
|
static void virtio_mem_handle_response(struct virtqueue *vq)
|
|
{
|
|
struct virtio_mem *vm = vq->vdev->priv;
|
|
|
|
wake_up(&vm->host_resp);
|
|
}
|
|
|
|
static int virtio_mem_init_vq(struct virtio_mem *vm)
|
|
{
|
|
struct virtqueue *vq;
|
|
|
|
vq = virtio_find_single_vq(vm->vdev, virtio_mem_handle_response,
|
|
"guest-request");
|
|
if (IS_ERR(vq))
|
|
return PTR_ERR(vq);
|
|
vm->vq = vq;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int virtio_mem_init(struct virtio_mem *vm)
|
|
{
|
|
const uint64_t phys_limit = 1UL << MAX_PHYSMEM_BITS;
|
|
uint16_t node_id;
|
|
|
|
if (!vm->vdev->config->get) {
|
|
dev_err(&vm->vdev->dev, "config access disabled\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
/*
|
|
* We don't want to (un)plug or reuse any memory when in kdump. The
|
|
* memory is still accessible (but not mapped).
|
|
*/
|
|
if (is_kdump_kernel()) {
|
|
dev_warn(&vm->vdev->dev, "disabled in kdump kernel\n");
|
|
return -EBUSY;
|
|
}
|
|
|
|
/* Fetch all properties that can't change. */
|
|
virtio_cread_le(vm->vdev, struct virtio_mem_config, plugged_size,
|
|
&vm->plugged_size);
|
|
virtio_cread_le(vm->vdev, struct virtio_mem_config, block_size,
|
|
&vm->device_block_size);
|
|
virtio_cread_le(vm->vdev, struct virtio_mem_config, node_id,
|
|
&node_id);
|
|
vm->nid = virtio_mem_translate_node_id(vm, node_id);
|
|
virtio_cread_le(vm->vdev, struct virtio_mem_config, addr, &vm->addr);
|
|
virtio_cread_le(vm->vdev, struct virtio_mem_config, region_size,
|
|
&vm->region_size);
|
|
|
|
/*
|
|
* We always hotplug memory in memory block granularity. This way,
|
|
* we have to wait for exactly one memory block to online.
|
|
*/
|
|
if (vm->device_block_size > memory_block_size_bytes()) {
|
|
dev_err(&vm->vdev->dev,
|
|
"The block size is not supported (too big).\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* bad device setup - warn only */
|
|
if (!IS_ALIGNED(vm->addr, memory_block_size_bytes()))
|
|
dev_warn(&vm->vdev->dev,
|
|
"The alignment of the physical start address can make some memory unusable.\n");
|
|
if (!IS_ALIGNED(vm->addr + vm->region_size, memory_block_size_bytes()))
|
|
dev_warn(&vm->vdev->dev,
|
|
"The alignment of the physical end address can make some memory unusable.\n");
|
|
if (vm->addr + vm->region_size > phys_limit)
|
|
dev_warn(&vm->vdev->dev,
|
|
"Some memory is not addressable. This can make some memory unusable.\n");
|
|
|
|
/*
|
|
* Calculate the subblock size:
|
|
* - At least MAX_ORDER - 1 / pageblock_order.
|
|
* - At least the device block size.
|
|
* In the worst case, a single subblock per memory block.
|
|
*/
|
|
vm->subblock_size = PAGE_SIZE * 1ul << max_t(uint32_t, MAX_ORDER - 1,
|
|
pageblock_order);
|
|
vm->subblock_size = max_t(uint64_t, vm->device_block_size,
|
|
vm->subblock_size);
|
|
vm->nb_sb_per_mb = memory_block_size_bytes() / vm->subblock_size;
|
|
|
|
/* Round up to the next full memory block */
|
|
vm->first_mb_id = virtio_mem_phys_to_mb_id(vm->addr - 1 +
|
|
memory_block_size_bytes());
|
|
vm->next_mb_id = vm->first_mb_id;
|
|
vm->last_mb_id = virtio_mem_phys_to_mb_id(vm->addr +
|
|
vm->region_size) - 1;
|
|
|
|
dev_info(&vm->vdev->dev, "start address: 0x%llx", vm->addr);
|
|
dev_info(&vm->vdev->dev, "region size: 0x%llx", vm->region_size);
|
|
dev_info(&vm->vdev->dev, "device block size: 0x%llx",
|
|
(unsigned long long)vm->device_block_size);
|
|
dev_info(&vm->vdev->dev, "memory block size: 0x%lx",
|
|
memory_block_size_bytes());
|
|
dev_info(&vm->vdev->dev, "subblock size: 0x%llx",
|
|
(unsigned long long)vm->subblock_size);
|
|
if (vm->nid != NUMA_NO_NODE)
|
|
dev_info(&vm->vdev->dev, "nid: %d", vm->nid);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int virtio_mem_create_resource(struct virtio_mem *vm)
|
|
{
|
|
/*
|
|
* When force-unloading the driver and removing the device, we
|
|
* could have a garbage pointer. Duplicate the string.
|
|
*/
|
|
const char *name = kstrdup(dev_name(&vm->vdev->dev), GFP_KERNEL);
|
|
|
|
if (!name)
|
|
return -ENOMEM;
|
|
|
|
vm->parent_resource = __request_mem_region(vm->addr, vm->region_size,
|
|
name, IORESOURCE_SYSTEM_RAM);
|
|
if (!vm->parent_resource) {
|
|
kfree(name);
|
|
dev_warn(&vm->vdev->dev, "could not reserve device region\n");
|
|
dev_info(&vm->vdev->dev,
|
|
"reloading the driver is not supported\n");
|
|
return -EBUSY;
|
|
}
|
|
|
|
/* The memory is not actually busy - make add_memory() work. */
|
|
vm->parent_resource->flags &= ~IORESOURCE_BUSY;
|
|
return 0;
|
|
}
|
|
|
|
static void virtio_mem_delete_resource(struct virtio_mem *vm)
|
|
{
|
|
const char *name;
|
|
|
|
if (!vm->parent_resource)
|
|
return;
|
|
|
|
name = vm->parent_resource->name;
|
|
release_resource(vm->parent_resource);
|
|
kfree(vm->parent_resource);
|
|
kfree(name);
|
|
vm->parent_resource = NULL;
|
|
}
|
|
|
|
static int virtio_mem_probe(struct virtio_device *vdev)
|
|
{
|
|
struct virtio_mem *vm;
|
|
int rc;
|
|
|
|
BUILD_BUG_ON(sizeof(struct virtio_mem_req) != 24);
|
|
BUILD_BUG_ON(sizeof(struct virtio_mem_resp) != 10);
|
|
|
|
vdev->priv = vm = kzalloc(sizeof(*vm), GFP_KERNEL);
|
|
if (!vm)
|
|
return -ENOMEM;
|
|
|
|
init_waitqueue_head(&vm->host_resp);
|
|
vm->vdev = vdev;
|
|
INIT_WORK(&vm->wq, virtio_mem_run_wq);
|
|
mutex_init(&vm->hotplug_mutex);
|
|
INIT_LIST_HEAD(&vm->next);
|
|
spin_lock_init(&vm->removal_lock);
|
|
hrtimer_init(&vm->retry_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
|
|
vm->retry_timer.function = virtio_mem_timer_expired;
|
|
vm->retry_timer_ms = VIRTIO_MEM_RETRY_TIMER_MIN_MS;
|
|
|
|
/* register the virtqueue */
|
|
rc = virtio_mem_init_vq(vm);
|
|
if (rc)
|
|
goto out_free_vm;
|
|
|
|
/* initialize the device by querying the config */
|
|
rc = virtio_mem_init(vm);
|
|
if (rc)
|
|
goto out_del_vq;
|
|
|
|
/* create the parent resource for all memory */
|
|
rc = virtio_mem_create_resource(vm);
|
|
if (rc)
|
|
goto out_del_vq;
|
|
|
|
/*
|
|
* If we still have memory plugged, we have to unplug all memory first.
|
|
* Registering our parent resource makes sure that this memory isn't
|
|
* actually in use (e.g., trying to reload the driver).
|
|
*/
|
|
if (vm->plugged_size) {
|
|
vm->unplug_all_required = 1;
|
|
dev_info(&vm->vdev->dev, "unplugging all memory is required\n");
|
|
}
|
|
|
|
/* register callbacks */
|
|
vm->memory_notifier.notifier_call = virtio_mem_memory_notifier_cb;
|
|
rc = register_memory_notifier(&vm->memory_notifier);
|
|
if (rc)
|
|
goto out_del_resource;
|
|
rc = register_virtio_mem_device(vm);
|
|
if (rc)
|
|
goto out_unreg_mem;
|
|
|
|
virtio_device_ready(vdev);
|
|
|
|
/* trigger a config update to start processing the requested_size */
|
|
atomic_set(&vm->config_changed, 1);
|
|
queue_work(system_freezable_wq, &vm->wq);
|
|
|
|
return 0;
|
|
out_unreg_mem:
|
|
unregister_memory_notifier(&vm->memory_notifier);
|
|
out_del_resource:
|
|
virtio_mem_delete_resource(vm);
|
|
out_del_vq:
|
|
vdev->config->del_vqs(vdev);
|
|
out_free_vm:
|
|
kfree(vm);
|
|
vdev->priv = NULL;
|
|
|
|
return rc;
|
|
}
|
|
|
|
static void virtio_mem_remove(struct virtio_device *vdev)
|
|
{
|
|
struct virtio_mem *vm = vdev->priv;
|
|
unsigned long mb_id;
|
|
int rc;
|
|
|
|
/*
|
|
* Make sure the workqueue won't be triggered anymore and no memory
|
|
* blocks can be onlined/offlined until we're finished here.
|
|
*/
|
|
mutex_lock(&vm->hotplug_mutex);
|
|
spin_lock_irq(&vm->removal_lock);
|
|
vm->removing = true;
|
|
spin_unlock_irq(&vm->removal_lock);
|
|
mutex_unlock(&vm->hotplug_mutex);
|
|
|
|
/* wait until the workqueue stopped */
|
|
cancel_work_sync(&vm->wq);
|
|
hrtimer_cancel(&vm->retry_timer);
|
|
|
|
/*
|
|
* After we unregistered our callbacks, user space can online partially
|
|
* plugged offline blocks. Make sure to remove them.
|
|
*/
|
|
virtio_mem_for_each_mb_state(vm, mb_id,
|
|
VIRTIO_MEM_MB_STATE_OFFLINE_PARTIAL) {
|
|
rc = virtio_mem_mb_remove(vm, mb_id);
|
|
BUG_ON(rc);
|
|
virtio_mem_mb_set_state(vm, mb_id, VIRTIO_MEM_MB_STATE_UNUSED);
|
|
}
|
|
/*
|
|
* After we unregistered our callbacks, user space can no longer
|
|
* offline partially plugged online memory blocks. No need to worry
|
|
* about them.
|
|
*/
|
|
|
|
/* unregister callbacks */
|
|
unregister_virtio_mem_device(vm);
|
|
unregister_memory_notifier(&vm->memory_notifier);
|
|
|
|
/*
|
|
* There is no way we could reliably remove all memory we have added to
|
|
* the system. And there is no way to stop the driver/device from going
|
|
* away. Warn at least.
|
|
*/
|
|
if (vm->nb_mb_state[VIRTIO_MEM_MB_STATE_OFFLINE] ||
|
|
vm->nb_mb_state[VIRTIO_MEM_MB_STATE_OFFLINE_PARTIAL] ||
|
|
vm->nb_mb_state[VIRTIO_MEM_MB_STATE_ONLINE] ||
|
|
vm->nb_mb_state[VIRTIO_MEM_MB_STATE_ONLINE_PARTIAL] ||
|
|
vm->nb_mb_state[VIRTIO_MEM_MB_STATE_ONLINE_MOVABLE]) {
|
|
dev_warn(&vdev->dev, "device still has system memory added\n");
|
|
} else {
|
|
virtio_mem_delete_resource(vm);
|
|
kfree_const(vm->resource_name);
|
|
}
|
|
|
|
/* remove all tracking data - no locking needed */
|
|
vfree(vm->mb_state);
|
|
vfree(vm->sb_bitmap);
|
|
|
|
/* reset the device and cleanup the queues */
|
|
vdev->config->reset(vdev);
|
|
vdev->config->del_vqs(vdev);
|
|
|
|
kfree(vm);
|
|
vdev->priv = NULL;
|
|
}
|
|
|
|
static void virtio_mem_config_changed(struct virtio_device *vdev)
|
|
{
|
|
struct virtio_mem *vm = vdev->priv;
|
|
|
|
atomic_set(&vm->config_changed, 1);
|
|
virtio_mem_retry(vm);
|
|
}
|
|
|
|
#ifdef CONFIG_PM_SLEEP
|
|
static int virtio_mem_freeze(struct virtio_device *vdev)
|
|
{
|
|
/*
|
|
* When restarting the VM, all memory is usually unplugged. Don't
|
|
* allow to suspend/hibernate.
|
|
*/
|
|
dev_err(&vdev->dev, "save/restore not supported.\n");
|
|
return -EPERM;
|
|
}
|
|
|
|
static int virtio_mem_restore(struct virtio_device *vdev)
|
|
{
|
|
return -EPERM;
|
|
}
|
|
#endif
|
|
|
|
static unsigned int virtio_mem_features[] = {
|
|
#if defined(CONFIG_NUMA) && defined(CONFIG_ACPI_NUMA)
|
|
VIRTIO_MEM_F_ACPI_PXM,
|
|
#endif
|
|
};
|
|
|
|
static struct virtio_device_id virtio_mem_id_table[] = {
|
|
{ VIRTIO_ID_MEM, VIRTIO_DEV_ANY_ID },
|
|
{ 0 },
|
|
};
|
|
|
|
static struct virtio_driver virtio_mem_driver = {
|
|
.feature_table = virtio_mem_features,
|
|
.feature_table_size = ARRAY_SIZE(virtio_mem_features),
|
|
.driver.name = KBUILD_MODNAME,
|
|
.driver.owner = THIS_MODULE,
|
|
.id_table = virtio_mem_id_table,
|
|
.probe = virtio_mem_probe,
|
|
.remove = virtio_mem_remove,
|
|
.config_changed = virtio_mem_config_changed,
|
|
#ifdef CONFIG_PM_SLEEP
|
|
.freeze = virtio_mem_freeze,
|
|
.restore = virtio_mem_restore,
|
|
#endif
|
|
};
|
|
|
|
module_virtio_driver(virtio_mem_driver);
|
|
MODULE_DEVICE_TABLE(virtio, virtio_mem_id_table);
|
|
MODULE_AUTHOR("David Hildenbrand <david@redhat.com>");
|
|
MODULE_DESCRIPTION("Virtio-mem driver");
|
|
MODULE_LICENSE("GPL");
|