module_param(unplug_online, bool, 0644);
MODULE_PARM_DESC(unplug_online, "Try to unplug online memory");
+static bool force_bbm;
+module_param(force_bbm, bool, 0444);
+MODULE_PARM_DESC(force_bbm,
+ "Force Big Block Mode. Default is 0 (auto-selection)");
+
+static unsigned long bbm_block_size;
+module_param(bbm_block_size, ulong, 0444);
+MODULE_PARM_DESC(bbm_block_size,
+ "Big Block size in bytes. Default is 0 (auto-detection).");
+
+static bool bbm_safe_unplug = true;
+module_param(bbm_safe_unplug, bool, 0444);
+MODULE_PARM_DESC(bbm_safe_unplug,
+ "Use a safe unplug mechanism in BBM, avoiding long/endless loops");
+
/*
* virtio-mem currently supports the following modes of operation:
*
- * * Sub Block Mode (SBM): A Linux memory block spans 1..X subblocks (SB). The
+ * * Sub Block Mode (SBM): A Linux memory block spans 2..X subblocks (SB). The
* size of a Sub Block (SB) is determined based on the device block size, the
* pageblock size, and the maximum allocation granularity of the buddy.
* Subblocks within a Linux memory block might either be plugged or unplugged.
* Memory is added/removed to Linux MM in Linux memory block granularity.
*
+ * * Big Block Mode (BBM): A Big Block (BB) spans 1..X Linux memory blocks.
+ * Memory is added/removed to Linux MM in Big Block granularity.
+ *
+ * The mode is determined automatically based on the Linux memory block size
+ * and the device block size.
+ *
* User space / core MM (auto onlining) is responsible for onlining added
* Linux memory blocks - and for selecting a zone. Linux Memory Blocks are
* always onlined separately, and all memory within a Linux memory block is
VIRTIO_MEM_SBM_MB_COUNT
};
+/*
+ * State of a Big Block (BB) in BBM, covering 1..X Linux memory blocks.
+ */
+enum virtio_mem_bbm_bb_state {
+ /* Unplugged, not added to Linux. Can be reused later. */
+ VIRTIO_MEM_BBM_BB_UNUSED = 0,
+ /* Plugged, not added to Linux. Error on add_memory(). */
+ VIRTIO_MEM_BBM_BB_PLUGGED,
+ /* Plugged and added to Linux. */
+ VIRTIO_MEM_BBM_BB_ADDED,
+ /* All online parts are fake-offline, ready to remove. */
+ VIRTIO_MEM_BBM_BB_FAKE_OFFLINE,
+ VIRTIO_MEM_BBM_BB_COUNT
+};
+
struct virtio_mem {
struct virtio_device *vdev;
atomic64_t offline_size;
uint64_t offline_threshold;
- struct {
- /* Id of the first memory block of this device. */
- unsigned long first_mb_id;
- /* Id of the last usable memory block of this device. */
- unsigned long last_usable_mb_id;
- /* Id of the next memory bock to prepare when needed. */
- unsigned long next_mb_id;
-
- /* The subblock size. */
- uint64_t sb_size;
- /* The number of subblocks per Linux memory block. */
- uint32_t sbs_per_mb;
-
- /* Summary of all memory block states. */
- unsigned long mb_count[VIRTIO_MEM_SBM_MB_COUNT];
-
- /*
- * One byte state per memory block. Allocated via vmalloc().
- * Resized (alloc+copy+free) on demand.
- *
- * With 128 MiB memory blocks, we have states for 512 GiB of
- * memory in one 4 KiB page.
- */
- uint8_t *mb_states;
-
- /*
- * Bitmap: one bit per subblock. Allocated similar to
- * sbm.mb_states.
- *
- * A set bit means the corresponding subblock is plugged,
- * otherwise it's unblocked.
- *
- * With 4 MiB subblocks, we manage 128 GiB of memory in one
- * 4 KiB page.
- */
- unsigned long *sb_states;
- } sbm;
+ /* If set, the driver is in SBM, otherwise in BBM. */
+ bool in_sbm;
+
+ union {
+ struct {
+ /* Id of the first memory block of this device. */
+ unsigned long first_mb_id;
+ /* Id of the last usable memory block of this device. */
+ unsigned long last_usable_mb_id;
+ /* Id of the next memory bock to prepare when needed. */
+ unsigned long next_mb_id;
+
+ /* The subblock size. */
+ uint64_t sb_size;
+ /* The number of subblocks per Linux memory block. */
+ uint32_t sbs_per_mb;
+
+ /* Summary of all memory block states. */
+ unsigned long mb_count[VIRTIO_MEM_SBM_MB_COUNT];
+
+ /*
+ * One byte state per memory block. Allocated via
+ * vmalloc(). Resized (alloc+copy+free) on demand.
+ *
+ * With 128 MiB memory blocks, we have states for 512
+ * GiB of memory in one 4 KiB page.
+ */
+ uint8_t *mb_states;
+
+ /*
+ * Bitmap: one bit per subblock. Allocated similar to
+ * sbm.mb_states.
+ *
+ * A set bit means the corresponding subblock is
+ * plugged, otherwise it's unblocked.
+ *
+ * With 4 MiB subblocks, we manage 128 GiB of memory
+ * in one 4 KiB page.
+ */
+ unsigned long *sb_states;
+ } sbm;
+
+ struct {
+ /* Id of the first big block of this device. */
+ unsigned long first_bb_id;
+ /* Id of the last usable big block of this device. */
+ unsigned long last_usable_bb_id;
+ /* Id of the next device bock to prepare when needed. */
+ unsigned long next_bb_id;
+
+ /* Summary of all big block states. */
+ unsigned long bb_count[VIRTIO_MEM_BBM_BB_COUNT];
+
+ /* One byte state per big block. See sbm.mb_states. */
+ uint8_t *bb_states;
+
+ /* The block size used for plugging/adding/removing. */
+ uint64_t bb_size;
+ } bbm;
+ };
/*
- * Mutex that protects the sbm.mb_count, sbm.mb_states, and
- * sbm.sb_states.
+ * Mutex that protects the sbm.mb_count, sbm.mb_states,
+ * sbm.sb_states, bbm.bb_count, and bbm.bb_states
*
* When this lock is held the pointers can't change, ONLINE and
* OFFLINE blocks can't change the state and no subblocks will get
return mb_id * memory_block_size_bytes();
}
+/*
+ * Calculate the big block id of a given address.
+ */
+static unsigned long virtio_mem_phys_to_bb_id(struct virtio_mem *vm,
+ uint64_t addr)
+{
+ return addr / vm->bbm.bb_size;
+}
+
+/*
+ * Calculate the physical start address of a given big block id.
+ */
+static uint64_t virtio_mem_bb_id_to_phys(struct virtio_mem *vm,
+ unsigned long bb_id)
+{
+ return bb_id * vm->bbm.bb_size;
+}
+
/*
* Calculate the subblock id of a given address.
*/
return (addr - mb_addr) / vm->sbm.sb_size;
}
+/*
+ * Set the state of a big block, taking care of the state counter.
+ */
+static void virtio_mem_bbm_set_bb_state(struct virtio_mem *vm,
+ unsigned long bb_id,
+ enum virtio_mem_bbm_bb_state state)
+{
+ const unsigned long idx = bb_id - vm->bbm.first_bb_id;
+ enum virtio_mem_bbm_bb_state old_state;
+
+ old_state = vm->bbm.bb_states[idx];
+ vm->bbm.bb_states[idx] = state;
+
+ BUG_ON(vm->bbm.bb_count[old_state] == 0);
+ vm->bbm.bb_count[old_state]--;
+ vm->bbm.bb_count[state]++;
+}
+
+/*
+ * Get the state of a big block.
+ */
+static enum virtio_mem_bbm_bb_state virtio_mem_bbm_get_bb_state(struct virtio_mem *vm,
+ unsigned long bb_id)
+{
+ return vm->bbm.bb_states[bb_id - vm->bbm.first_bb_id];
+}
+
+/*
+ * Prepare the big block state array for the next big block.
+ */
+static int virtio_mem_bbm_bb_states_prepare_next_bb(struct virtio_mem *vm)
+{
+ unsigned long old_bytes = vm->bbm.next_bb_id - vm->bbm.first_bb_id;
+ unsigned long new_bytes = old_bytes + 1;
+ int old_pages = PFN_UP(old_bytes);
+ int new_pages = PFN_UP(new_bytes);
+ uint8_t *new_array;
+
+ if (vm->bbm.bb_states && old_pages == new_pages)
+ return 0;
+
+ new_array = vzalloc(new_pages * PAGE_SIZE);
+ if (!new_array)
+ return -ENOMEM;
+
+ mutex_lock(&vm->hotplug_mutex);
+ if (vm->bbm.bb_states)
+ memcpy(new_array, vm->bbm.bb_states, old_pages * PAGE_SIZE);
+ vfree(vm->bbm.bb_states);
+ vm->bbm.bb_states = new_array;
+ mutex_unlock(&vm->hotplug_mutex);
+
+ return 0;
+}
+
+#define virtio_mem_bbm_for_each_bb(_vm, _bb_id, _state) \
+ for (_bb_id = vm->bbm.first_bb_id; \
+ _bb_id < vm->bbm.next_bb_id && _vm->bbm.bb_count[_state]; \
+ _bb_id++) \
+ if (virtio_mem_bbm_get_bb_state(_vm, _bb_id) == _state)
+
+#define virtio_mem_bbm_for_each_bb_rev(_vm, _bb_id, _state) \
+ for (_bb_id = vm->bbm.next_bb_id - 1; \
+ _bb_id >= vm->bbm.first_bb_id && _vm->bbm.bb_count[_state]; \
+ _bb_id--) \
+ if (virtio_mem_bbm_get_bb_state(_vm, _bb_id) == _state)
+
/*
* Set the state of a memory block, taking care of the state counter.
*/
}
/*
- * Try to add a memory block to Linux. This will usually only fail
- * if out of memory.
+ * Try adding memory to Linux. Will usually only fail if out of memory.
*
* Must not be called with the vm->hotplug_mutex held (possible deadlock with
* onlining code).
*
- * Will not modify the state of the memory block.
+ * Will not modify the state of memory blocks in virtio-mem.
*/
-static int virtio_mem_mb_add(struct virtio_mem *vm, unsigned long mb_id)
+static int virtio_mem_add_memory(struct virtio_mem *vm, uint64_t addr,
+ uint64_t size)
{
- const uint64_t addr = virtio_mem_mb_id_to_phys(mb_id);
- const uint64_t size = memory_block_size_bytes();
int rc;
/*
return -ENOMEM;
}
- dev_dbg(&vm->vdev->dev, "adding memory block: %lu\n", mb_id);
+ dev_dbg(&vm->vdev->dev, "adding memory: 0x%llx - 0x%llx\n", addr,
+ addr + size - 1);
/* Memory might get onlined immediately. */
atomic64_add(size, &vm->offline_size);
rc = add_memory_driver_managed(vm->nid, addr, size, vm->resource_name,
MEMHP_MERGE_RESOURCE);
- if (rc)
+ if (rc) {
atomic64_sub(size, &vm->offline_size);
+ dev_warn(&vm->vdev->dev, "adding memory failed: %d\n", rc);
+ /*
+ * TODO: Linux MM does not properly clean up yet in all cases
+ * where adding of memory failed - especially on -ENOMEM.
+ */
+ }
return rc;
}
/*
- * Try to remove a memory block from Linux. Will only fail if the memory block
- * is not offline.
+ * See virtio_mem_add_memory(): Try adding a single Linux memory block.
+ */
+static int virtio_mem_sbm_add_mb(struct virtio_mem *vm, unsigned long mb_id)
+{
+ const uint64_t addr = virtio_mem_mb_id_to_phys(mb_id);
+ const uint64_t size = memory_block_size_bytes();
+
+ return virtio_mem_add_memory(vm, addr, size);
+}
+
+/*
+ * See virtio_mem_add_memory(): Try adding a big block.
+ */
+static int virtio_mem_bbm_add_bb(struct virtio_mem *vm, unsigned long bb_id)
+{
+ const uint64_t addr = virtio_mem_bb_id_to_phys(vm, bb_id);
+ const uint64_t size = vm->bbm.bb_size;
+
+ return virtio_mem_add_memory(vm, addr, size);
+}
+
+/*
+ * Try removing memory from Linux. Will only fail if memory blocks aren't
+ * offline.
*
* Must not be called with the vm->hotplug_mutex held (possible deadlock with
* onlining code).
*
- * Will not modify the state of the memory block.
+ * Will not modify the state of memory blocks in virtio-mem.
*/
-static int virtio_mem_mb_remove(struct virtio_mem *vm, unsigned long mb_id)
+static int virtio_mem_remove_memory(struct virtio_mem *vm, uint64_t addr,
+ uint64_t size)
{
- const uint64_t addr = virtio_mem_mb_id_to_phys(mb_id);
- const uint64_t size = memory_block_size_bytes();
int rc;
- dev_dbg(&vm->vdev->dev, "removing memory block: %lu\n", mb_id);
+ dev_dbg(&vm->vdev->dev, "removing memory: 0x%llx - 0x%llx\n", addr,
+ addr + size - 1);
rc = remove_memory(vm->nid, addr, size);
if (!rc) {
atomic64_sub(size, &vm->offline_size);
* immediately instead of waiting.
*/
virtio_mem_retry(vm);
+ } else {
+ dev_dbg(&vm->vdev->dev, "removing memory failed: %d\n", rc);
}
return rc;
}
/*
- * Try to offline and remove a memory block from Linux.
+ * See virtio_mem_remove_memory(): Try removing a single Linux memory block.
+ */
+static int virtio_mem_sbm_remove_mb(struct virtio_mem *vm, unsigned long mb_id)
+{
+ const uint64_t addr = virtio_mem_mb_id_to_phys(mb_id);
+ const uint64_t size = memory_block_size_bytes();
+
+ return virtio_mem_remove_memory(vm, addr, size);
+}
+
+/*
+ * See virtio_mem_remove_memory(): Try to remove all Linux memory blocks covered
+ * by the big block.
+ */
+static int virtio_mem_bbm_remove_bb(struct virtio_mem *vm, unsigned long bb_id)
+{
+ const uint64_t addr = virtio_mem_bb_id_to_phys(vm, bb_id);
+ const uint64_t size = vm->bbm.bb_size;
+
+ return virtio_mem_remove_memory(vm, addr, size);
+}
+
+/*
+ * Try offlining and removing memory from Linux.
*
* Must not be called with the vm->hotplug_mutex held (possible deadlock with
* onlining code).
*
- * Will not modify the state of the memory block.
+ * Will not modify the state of memory blocks in virtio-mem.
*/
-static int virtio_mem_mb_offline_and_remove(struct virtio_mem *vm,
- unsigned long mb_id)
+static int virtio_mem_offline_and_remove_memory(struct virtio_mem *vm,
+ uint64_t addr,
+ uint64_t size)
{
- const uint64_t addr = virtio_mem_mb_id_to_phys(mb_id);
- const uint64_t size = memory_block_size_bytes();
int rc;
- dev_dbg(&vm->vdev->dev, "offlining and removing memory block: %lu\n",
- mb_id);
+ dev_dbg(&vm->vdev->dev,
+ "offlining and removing memory: 0x%llx - 0x%llx\n", addr,
+ addr + size - 1);
+
rc = offline_and_remove_memory(vm->nid, addr, size);
if (!rc) {
atomic64_sub(size, &vm->offline_size);
* immediately instead of waiting.
*/
virtio_mem_retry(vm);
+ } else {
+ dev_dbg(&vm->vdev->dev,
+ "offlining and removing memory failed: %d\n", rc);
}
return rc;
}
+/*
+ * See virtio_mem_offline_and_remove_memory(): Try offlining and removing
+ * a single Linux memory block.
+ */
+static int virtio_mem_sbm_offline_and_remove_mb(struct virtio_mem *vm,
+ unsigned long mb_id)
+{
+ const uint64_t addr = virtio_mem_mb_id_to_phys(mb_id);
+ const uint64_t size = memory_block_size_bytes();
+
+ return virtio_mem_offline_and_remove_memory(vm, addr, size);
+}
+
+/*
+ * See virtio_mem_offline_and_remove_memory(): Try to offline and remove a
+ * all Linux memory blocks covered by the big block.
+ */
+static int virtio_mem_bbm_offline_and_remove_bb(struct virtio_mem *vm,
+ unsigned long bb_id)
+{
+ const uint64_t addr = virtio_mem_bb_id_to_phys(vm, bb_id);
+ const uint64_t size = vm->bbm.bb_size;
+
+ return virtio_mem_offline_and_remove_memory(vm, addr, size);
+}
+
/*
* Trigger the workqueue so the device can perform its magic.
*/
}
}
+static void virtio_mem_bbm_notify_going_offline(struct virtio_mem *vm,
+ unsigned long bb_id,
+ unsigned long pfn,
+ unsigned long nr_pages)
+{
+ /*
+ * When marked as "fake-offline", all online memory of this device block
+ * is allocated by us. Otherwise, we don't have any memory allocated.
+ */
+ if (virtio_mem_bbm_get_bb_state(vm, bb_id) !=
+ VIRTIO_MEM_BBM_BB_FAKE_OFFLINE)
+ return;
+ virtio_mem_fake_offline_going_offline(pfn, nr_pages);
+}
+
+static void virtio_mem_bbm_notify_cancel_offline(struct virtio_mem *vm,
+ unsigned long bb_id,
+ unsigned long pfn,
+ unsigned long nr_pages)
+{
+ if (virtio_mem_bbm_get_bb_state(vm, bb_id) !=
+ VIRTIO_MEM_BBM_BB_FAKE_OFFLINE)
+ return;
+ virtio_mem_fake_offline_cancel_offline(pfn, nr_pages);
+}
+
/*
* This callback will either be called synchronously from add_memory() or
* asynchronously (e.g., triggered via user space). We have to be careful
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);
int rc = NOTIFY_OK;
+ unsigned long id;
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;
+ if (vm->in_sbm) {
+ id = virtio_mem_phys_to_mb_id(start);
+ /*
+ * In SBM, we add memory in separate memory blocks - we expect
+ * it to be onlined/offlined in the same granularity. 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;
+ } else {
+ id = virtio_mem_phys_to_bb_id(vm, start);
+ /*
+ * In BBM, we only care about onlining/offlining happening
+ * within a single big block, we don't care about the
+ * actual granularity as we don't track individual Linux
+ * memory blocks.
+ */
+ if (WARN_ON_ONCE(id != virtio_mem_phys_to_bb_id(vm, start + size - 1)))
+ return NOTIFY_BAD;
+ }
/*
* Avoid circular locking lockdep warnings. We lock the mutex
break;
}
vm->hotplug_active = true;
- virtio_mem_sbm_notify_going_offline(vm, mb_id);
+ if (vm->in_sbm)
+ virtio_mem_sbm_notify_going_offline(vm, id);
+ else
+ virtio_mem_bbm_notify_going_offline(vm, id,
+ mhp->start_pfn,
+ mhp->nr_pages);
break;
case MEM_GOING_ONLINE:
mutex_lock(&vm->hotplug_mutex);
break;
}
vm->hotplug_active = true;
- rc = virtio_mem_sbm_notify_going_online(vm, mb_id);
+ if (vm->in_sbm)
+ rc = virtio_mem_sbm_notify_going_online(vm, id);
break;
case MEM_OFFLINE:
- virtio_mem_sbm_notify_offline(vm, mb_id);
+ if (vm->in_sbm)
+ virtio_mem_sbm_notify_offline(vm, id);
atomic64_add(size, &vm->offline_size);
/*
mutex_unlock(&vm->hotplug_mutex);
break;
case MEM_ONLINE:
- virtio_mem_sbm_notify_online(vm, mb_id);
+ if (vm->in_sbm)
+ virtio_mem_sbm_notify_online(vm, id);
atomic64_sub(size, &vm->offline_size);
/*
case MEM_CANCEL_OFFLINE:
if (!vm->hotplug_active)
break;
- virtio_mem_sbm_notify_cancel_offline(vm, mb_id);
+ if (vm->in_sbm)
+ virtio_mem_sbm_notify_cancel_offline(vm, id);
+ else
+ virtio_mem_bbm_notify_cancel_offline(vm, id,
+ mhp->start_pfn,
+ mhp->nr_pages);
vm->hotplug_active = false;
mutex_unlock(&vm->hotplug_mutex);
break;
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);
+ unsigned long id, sb_id;
struct virtio_mem *vm;
- int sb_id;
+ bool do_online;
- /*
- * We exploit here that subblocks have at least MAX_ORDER_NR_PAGES.
- * 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_contains_range(vm, addr, PFN_PHYS(1 << order)))
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_sbm_test_sb_plugged(vm, mb_id, sb_id, 1))
+ if (vm->in_sbm) {
+ /*
+ * We exploit here that subblocks have at least
+ * MAX_ORDER_NR_PAGES size/alignment - so we cannot
+ * cross subblocks within one call.
+ */
+ id = virtio_mem_phys_to_mb_id(addr);
+ sb_id = virtio_mem_phys_to_sb_id(vm, addr);
+ do_online = virtio_mem_sbm_test_sb_plugged(vm, id,
+ sb_id, 1);
+ } else {
+ /*
+ * If the whole block is marked fake offline, keep
+ * everything that way.
+ */
+ id = virtio_mem_phys_to_bb_id(vm, addr);
+ do_online = virtio_mem_bbm_get_bb_state(vm, id) !=
+ VIRTIO_MEM_BBM_BB_FAKE_OFFLINE;
+ }
+ if (do_online)
generic_online_page(page, order);
else
virtio_mem_set_fake_offline(PFN_DOWN(addr), 1 << order,
return rc;
}
+/*
+ * Request to unplug a big block.
+ *
+ * Will not modify the state of the big block.
+ */
+static int virtio_mem_bbm_unplug_bb(struct virtio_mem *vm, unsigned long bb_id)
+{
+ const uint64_t addr = virtio_mem_bb_id_to_phys(vm, bb_id);
+ const uint64_t size = vm->bbm.bb_size;
+
+ return virtio_mem_send_unplug_request(vm, addr, size);
+}
+
+/*
+ * Request to plug a big block.
+ *
+ * Will not modify the state of the big block.
+ */
+static int virtio_mem_bbm_plug_bb(struct virtio_mem *vm, unsigned long bb_id)
+{
+ const uint64_t addr = virtio_mem_bb_id_to_phys(vm, bb_id);
+ const uint64_t size = vm->bbm.bb_size;
+
+ return virtio_mem_send_plug_request(vm, addr, size);
+}
+
/*
* 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
VIRTIO_MEM_SBM_MB_OFFLINE_PARTIAL);
/* Add the memory block to linux - if that fails, try to unplug. */
- rc = virtio_mem_mb_add(vm, mb_id);
+ rc = virtio_mem_sbm_add_mb(vm, mb_id);
if (rc) {
int new_state = VIRTIO_MEM_SBM_MB_UNUSED;
- dev_err(&vm->vdev->dev,
- "adding memory block %lu failed with %d\n", mb_id, rc);
-
- /*
- * TODO: Linux MM does not properly clean up yet in all cases
- * where adding of memory failed - especially on -ENOMEM.
- */
if (virtio_mem_sbm_unplug_sb(vm, mb_id, 0, count))
new_state = VIRTIO_MEM_SBM_MB_PLUGGED;
virtio_mem_sbm_set_mb_state(vm, mb_id, new_state);
return 0;
}
-/*
- * Try to plug the requested amount of memory.
- */
-static int virtio_mem_plug_request(struct virtio_mem *vm, uint64_t diff)
+static int virtio_mem_sbm_plug_request(struct virtio_mem *vm, uint64_t diff)
{
uint64_t nb_sb = diff / vm->sbm.sb_size;
unsigned long mb_id;
return rc;
}
+/*
+ * Plug a big block and add it to Linux.
+ *
+ * Will modify the state of the big block.
+ */
+static int virtio_mem_bbm_plug_and_add_bb(struct virtio_mem *vm,
+ unsigned long bb_id)
+{
+ int rc;
+
+ if (WARN_ON_ONCE(virtio_mem_bbm_get_bb_state(vm, bb_id) !=
+ VIRTIO_MEM_BBM_BB_UNUSED))
+ return -EINVAL;
+
+ rc = virtio_mem_bbm_plug_bb(vm, bb_id);
+ if (rc)
+ return rc;
+ virtio_mem_bbm_set_bb_state(vm, bb_id, VIRTIO_MEM_BBM_BB_ADDED);
+
+ rc = virtio_mem_bbm_add_bb(vm, bb_id);
+ if (rc) {
+ if (!virtio_mem_bbm_unplug_bb(vm, bb_id))
+ virtio_mem_bbm_set_bb_state(vm, bb_id,
+ VIRTIO_MEM_BBM_BB_UNUSED);
+ else
+ /* Retry from the main loop. */
+ virtio_mem_bbm_set_bb_state(vm, bb_id,
+ VIRTIO_MEM_BBM_BB_PLUGGED);
+ return rc;
+ }
+ return 0;
+}
+
+/*
+ * Prepare tracking data for the next big block.
+ */
+static int virtio_mem_bbm_prepare_next_bb(struct virtio_mem *vm,
+ unsigned long *bb_id)
+{
+ int rc;
+
+ if (vm->bbm.next_bb_id > vm->bbm.last_usable_bb_id)
+ return -ENOSPC;
+
+ /* Resize the big block state array if required. */
+ rc = virtio_mem_bbm_bb_states_prepare_next_bb(vm);
+ if (rc)
+ return rc;
+
+ vm->bbm.bb_count[VIRTIO_MEM_BBM_BB_UNUSED]++;
+ *bb_id = vm->bbm.next_bb_id;
+ vm->bbm.next_bb_id++;
+ return 0;
+}
+
+static int virtio_mem_bbm_plug_request(struct virtio_mem *vm, uint64_t diff)
+{
+ uint64_t nb_bb = diff / vm->bbm.bb_size;
+ unsigned long bb_id;
+ int rc;
+
+ if (!nb_bb)
+ return 0;
+
+ /* Try to plug and add unused big blocks */
+ virtio_mem_bbm_for_each_bb(vm, bb_id, VIRTIO_MEM_BBM_BB_UNUSED) {
+ if (!virtio_mem_could_add_memory(vm, vm->bbm.bb_size))
+ return -ENOSPC;
+
+ rc = virtio_mem_bbm_plug_and_add_bb(vm, bb_id);
+ if (!rc)
+ nb_bb--;
+ if (rc || !nb_bb)
+ return rc;
+ cond_resched();
+ }
+
+ /* Try to prepare, plug and add new big blocks */
+ while (nb_bb) {
+ if (!virtio_mem_could_add_memory(vm, vm->bbm.bb_size))
+ return -ENOSPC;
+
+ rc = virtio_mem_bbm_prepare_next_bb(vm, &bb_id);
+ if (rc)
+ return rc;
+ rc = virtio_mem_bbm_plug_and_add_bb(vm, bb_id);
+ if (!rc)
+ nb_bb--;
+ if (rc)
+ return rc;
+ cond_resched();
+ }
+
+ return 0;
+}
+
+/*
+ * Try to plug the requested amount of memory.
+ */
+static int virtio_mem_plug_request(struct virtio_mem *vm, uint64_t diff)
+{
+ if (vm->in_sbm)
+ return virtio_mem_sbm_plug_request(vm, diff);
+ return virtio_mem_bbm_plug_request(vm, diff);
+}
+
/*
* Unplug the desired number of plugged subblocks of an offline memory block.
* Will fail if any subblock cannot get unplugged (instead of skipping it).
VIRTIO_MEM_SBM_MB_UNUSED);
mutex_unlock(&vm->hotplug_mutex);
- rc = virtio_mem_mb_remove(vm, mb_id);
+ rc = virtio_mem_sbm_remove_mb(vm, mb_id);
BUG_ON(rc);
mutex_lock(&vm->hotplug_mutex);
}
*/
if (virtio_mem_sbm_test_sb_unplugged(vm, mb_id, 0, vm->sbm.sbs_per_mb)) {
mutex_unlock(&vm->hotplug_mutex);
- rc = virtio_mem_mb_offline_and_remove(vm, mb_id);
+ rc = virtio_mem_sbm_offline_and_remove_mb(vm, mb_id);
mutex_lock(&vm->hotplug_mutex);
if (!rc)
virtio_mem_sbm_set_mb_state(vm, mb_id,
return 0;
}
-/*
- * Try to unplug the requested amount of memory.
- */
-static int virtio_mem_unplug_request(struct virtio_mem *vm, uint64_t diff)
+static int virtio_mem_sbm_unplug_request(struct virtio_mem *vm, uint64_t diff)
{
uint64_t nb_sb = diff / vm->sbm.sb_size;
unsigned long mb_id;
return rc;
}
+/*
+ * Try to offline and remove a big block from Linux and unplug it. Will fail
+ * with -EBUSY if some memory is busy and cannot get unplugged.
+ *
+ * Will modify the state of the memory block. Might temporarily drop the
+ * hotplug_mutex.
+ */
+static int virtio_mem_bbm_offline_remove_and_unplug_bb(struct virtio_mem *vm,
+ unsigned long bb_id)
+{
+ const unsigned long start_pfn = PFN_DOWN(virtio_mem_bb_id_to_phys(vm, bb_id));
+ const unsigned long nr_pages = PFN_DOWN(vm->bbm.bb_size);
+ unsigned long end_pfn = start_pfn + nr_pages;
+ unsigned long pfn;
+ struct page *page;
+ int rc;
+
+ if (WARN_ON_ONCE(virtio_mem_bbm_get_bb_state(vm, bb_id) !=
+ VIRTIO_MEM_BBM_BB_ADDED))
+ return -EINVAL;
+
+ if (bbm_safe_unplug) {
+ /*
+ * Start by fake-offlining all memory. Once we marked the device
+ * block as fake-offline, all newly onlined memory will
+ * automatically be kept fake-offline. Protect from concurrent
+ * onlining/offlining until we have a consistent state.
+ */
+ mutex_lock(&vm->hotplug_mutex);
+ virtio_mem_bbm_set_bb_state(vm, bb_id,
+ VIRTIO_MEM_BBM_BB_FAKE_OFFLINE);
+
+ for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
+ page = pfn_to_online_page(pfn);
+ if (!page)
+ continue;
+
+ rc = virtio_mem_fake_offline(pfn, PAGES_PER_SECTION);
+ if (rc) {
+ end_pfn = pfn;
+ goto rollback_safe_unplug;
+ }
+ }
+ mutex_unlock(&vm->hotplug_mutex);
+ }
+
+ rc = virtio_mem_bbm_offline_and_remove_bb(vm, bb_id);
+ if (rc) {
+ if (bbm_safe_unplug) {
+ mutex_lock(&vm->hotplug_mutex);
+ goto rollback_safe_unplug;
+ }
+ return rc;
+ }
+
+ rc = virtio_mem_bbm_unplug_bb(vm, bb_id);
+ if (rc)
+ virtio_mem_bbm_set_bb_state(vm, bb_id,
+ VIRTIO_MEM_BBM_BB_PLUGGED);
+ else
+ virtio_mem_bbm_set_bb_state(vm, bb_id,
+ VIRTIO_MEM_BBM_BB_UNUSED);
+ return rc;
+
+rollback_safe_unplug:
+ for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
+ page = pfn_to_online_page(pfn);
+ if (!page)
+ continue;
+ virtio_mem_fake_online(pfn, PAGES_PER_SECTION);
+ }
+ virtio_mem_bbm_set_bb_state(vm, bb_id, VIRTIO_MEM_BBM_BB_ADDED);
+ mutex_unlock(&vm->hotplug_mutex);
+ return rc;
+}
+
+/*
+ * Try to remove a big block from Linux and unplug it. Will fail with
+ * -EBUSY if some memory is online.
+ *
+ * Will modify the state of the memory block.
+ */
+static int virtio_mem_bbm_remove_and_unplug_bb(struct virtio_mem *vm,
+ unsigned long bb_id)
+{
+ int rc;
+
+ if (WARN_ON_ONCE(virtio_mem_bbm_get_bb_state(vm, bb_id) !=
+ VIRTIO_MEM_BBM_BB_ADDED))
+ return -EINVAL;
+
+ rc = virtio_mem_bbm_remove_bb(vm, bb_id);
+ if (rc)
+ return -EBUSY;
+
+ rc = virtio_mem_bbm_unplug_bb(vm, bb_id);
+ if (rc)
+ virtio_mem_bbm_set_bb_state(vm, bb_id,
+ VIRTIO_MEM_BBM_BB_PLUGGED);
+ else
+ virtio_mem_bbm_set_bb_state(vm, bb_id,
+ VIRTIO_MEM_BBM_BB_UNUSED);
+ return rc;
+}
+
+/*
+ * Test if a big block is completely offline.
+ */
+static bool virtio_mem_bbm_bb_is_offline(struct virtio_mem *vm,
+ unsigned long bb_id)
+{
+ const unsigned long start_pfn = PFN_DOWN(virtio_mem_bb_id_to_phys(vm, bb_id));
+ const unsigned long nr_pages = PFN_DOWN(vm->bbm.bb_size);
+ unsigned long pfn;
+
+ for (pfn = start_pfn; pfn < start_pfn + nr_pages;
+ pfn += PAGES_PER_SECTION) {
+ if (pfn_to_online_page(pfn))
+ return false;
+ }
+
+ return true;
+}
+
+static int virtio_mem_bbm_unplug_request(struct virtio_mem *vm, uint64_t diff)
+{
+ uint64_t nb_bb = diff / vm->bbm.bb_size;
+ uint64_t bb_id;
+ int rc;
+
+ if (!nb_bb)
+ return 0;
+
+ /* Try to unplug completely offline big blocks first. */
+ virtio_mem_bbm_for_each_bb_rev(vm, bb_id, VIRTIO_MEM_BBM_BB_ADDED) {
+ cond_resched();
+ /*
+ * As we're holding no locks, this check is racy as memory
+ * can get onlined in the meantime - but we'll fail gracefully.
+ */
+ if (!virtio_mem_bbm_bb_is_offline(vm, bb_id))
+ continue;
+ rc = virtio_mem_bbm_remove_and_unplug_bb(vm, bb_id);
+ if (rc == -EBUSY)
+ continue;
+ if (!rc)
+ nb_bb--;
+ if (rc || !nb_bb)
+ return rc;
+ }
+
+ if (!unplug_online)
+ return 0;
+
+ /* Try to unplug any big blocks. */
+ virtio_mem_bbm_for_each_bb_rev(vm, bb_id, VIRTIO_MEM_BBM_BB_ADDED) {
+ cond_resched();
+ rc = virtio_mem_bbm_offline_remove_and_unplug_bb(vm, bb_id);
+ if (rc == -EBUSY)
+ continue;
+ if (!rc)
+ nb_bb--;
+ if (rc || !nb_bb)
+ return rc;
+ }
+
+ return nb_bb ? -EBUSY : 0;
+}
+
+/*
+ * Try to unplug the requested amount of memory.
+ */
+static int virtio_mem_unplug_request(struct virtio_mem *vm, uint64_t diff)
+{
+ if (vm->in_sbm)
+ return virtio_mem_sbm_unplug_request(vm, diff);
+ return virtio_mem_bbm_unplug_request(vm, diff);
+}
+
/*
* 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;
+ unsigned long id;
int rc;
- virtio_mem_sbm_for_each_mb(vm, mb_id, VIRTIO_MEM_SBM_MB_PLUGGED) {
- rc = virtio_mem_sbm_unplug_mb(vm, mb_id);
+ if (!vm->in_sbm) {
+ virtio_mem_bbm_for_each_bb(vm, id,
+ VIRTIO_MEM_BBM_BB_PLUGGED) {
+ rc = virtio_mem_bbm_unplug_bb(vm, id);
+ if (rc)
+ return rc;
+ virtio_mem_bbm_set_bb_state(vm, id,
+ VIRTIO_MEM_BBM_BB_UNUSED);
+ }
+ return 0;
+ }
+
+ virtio_mem_sbm_for_each_mb(vm, id, VIRTIO_MEM_SBM_MB_PLUGGED) {
+ rc = virtio_mem_sbm_unplug_mb(vm, id);
if (rc)
return rc;
- virtio_mem_sbm_set_mb_state(vm, mb_id,
+ virtio_mem_sbm_set_mb_state(vm, id,
VIRTIO_MEM_SBM_MB_UNUSED);
}
usable_region_size, &usable_region_size);
end_addr = vm->addr + usable_region_size;
end_addr = min(end_addr, phys_limit);
- vm->sbm.last_usable_mb_id = virtio_mem_phys_to_mb_id(end_addr) - 1;
+
+ if (vm->in_sbm)
+ vm->sbm.last_usable_mb_id =
+ virtio_mem_phys_to_mb_id(end_addr) - 1;
+ else
+ vm->bbm.last_usable_bb_id =
+ virtio_mem_phys_to_bb_id(vm, end_addr) - 1;
/* see if there is a request to change the size */
virtio_cread_le(vm->vdev, struct virtio_mem_config, requested_size,
static int virtio_mem_init(struct virtio_mem *vm)
{
const uint64_t phys_limit = 1UL << MAX_PHYSMEM_BITS;
+ uint64_t sb_size, addr;
uint16_t node_id;
if (!vm->vdev->config->get) {
if (vm->nid == NUMA_NO_NODE)
vm->nid = memory_add_physaddr_to_nid(vm->addr);
- /*
- * 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,
* - Is required for now for alloc_contig_range() to work reliably -
* it doesn't properly handle smaller granularity on ZONE_NORMAL.
*/
- vm->sbm.sb_size = max_t(uint64_t, MAX_ORDER_NR_PAGES,
- pageblock_nr_pages) * PAGE_SIZE;
- vm->sbm.sb_size = max_t(uint64_t, vm->device_block_size,
- vm->sbm.sb_size);
- vm->sbm.sbs_per_mb = memory_block_size_bytes() / vm->sbm.sb_size;
+ sb_size = max_t(uint64_t, MAX_ORDER_NR_PAGES,
+ pageblock_nr_pages) * PAGE_SIZE;
+ sb_size = max_t(uint64_t, vm->device_block_size, sb_size);
+
+ if (sb_size < memory_block_size_bytes() && !force_bbm) {
+ /* SBM: At least two subblocks per Linux memory block. */
+ vm->in_sbm = true;
+ vm->sbm.sb_size = sb_size;
+ vm->sbm.sbs_per_mb = memory_block_size_bytes() /
+ vm->sbm.sb_size;
+
+ /* Round up to the next full memory block */
+ addr = vm->addr + memory_block_size_bytes() - 1;
+ vm->sbm.first_mb_id = virtio_mem_phys_to_mb_id(addr);
+ vm->sbm.next_mb_id = vm->sbm.first_mb_id;
+ } else {
+ /* BBM: At least one Linux memory block. */
+ vm->bbm.bb_size = max_t(uint64_t, vm->device_block_size,
+ memory_block_size_bytes());
+
+ if (bbm_block_size) {
+ if (!is_power_of_2(bbm_block_size)) {
+ dev_warn(&vm->vdev->dev,
+ "bbm_block_size is not a power of 2");
+ } else if (bbm_block_size < vm->bbm.bb_size) {
+ dev_warn(&vm->vdev->dev,
+ "bbm_block_size is too small");
+ } else {
+ vm->bbm.bb_size = bbm_block_size;
+ }
+ }
- /* Round up to the next full memory block */
- vm->sbm.first_mb_id = virtio_mem_phys_to_mb_id(vm->addr - 1 +
- memory_block_size_bytes());
- vm->sbm.next_mb_id = vm->sbm.first_mb_id;
+ /* Round up to the next aligned big block */
+ addr = vm->addr + vm->bbm.bb_size - 1;
+ vm->bbm.first_bb_id = virtio_mem_phys_to_bb_id(vm, addr);
+ vm->bbm.next_bb_id = vm->bbm.first_bb_id;
+ }
/* Prepare the offline threshold - make sure we can add two blocks. */
vm->offline_threshold = max_t(uint64_t, 2 * memory_block_size_bytes(),
VIRTIO_MEM_DEFAULT_OFFLINE_THRESHOLD);
+ /* In BBM, we also want at least two big blocks. */
+ vm->offline_threshold = max_t(uint64_t, 2 * vm->bbm.bb_size,
+ vm->offline_threshold);
dev_info(&vm->vdev->dev, "start address: 0x%llx", vm->addr);
dev_info(&vm->vdev->dev, "region size: 0x%llx", vm->region_size);
(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->sbm.sb_size);
+ if (vm->in_sbm)
+ dev_info(&vm->vdev->dev, "subblock size: 0x%llx",
+ (unsigned long long)vm->sbm.sb_size);
+ else
+ dev_info(&vm->vdev->dev, "big block size: 0x%llx",
+ (unsigned long long)vm->bbm.bb_size);
if (vm->nid != NUMA_NO_NODE && IS_ENABLED(CONFIG_NUMA))
dev_info(&vm->vdev->dev, "nid: %d", vm->nid);
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_sbm_for_each_mb(vm, mb_id,
- VIRTIO_MEM_SBM_MB_OFFLINE_PARTIAL) {
- rc = virtio_mem_mb_remove(vm, mb_id);
- BUG_ON(rc);
- virtio_mem_sbm_set_mb_state(vm, mb_id,
- VIRTIO_MEM_SBM_MB_UNUSED);
+ if (vm->in_sbm) {
+ /*
+ * After we unregistered our callbacks, user space can online
+ * partially plugged offline blocks. Make sure to remove them.
+ */
+ virtio_mem_sbm_for_each_mb(vm, mb_id,
+ VIRTIO_MEM_SBM_MB_OFFLINE_PARTIAL) {
+ rc = virtio_mem_sbm_remove_mb(vm, mb_id);
+ BUG_ON(rc);
+ virtio_mem_sbm_set_mb_state(vm, mb_id,
+ VIRTIO_MEM_SBM_MB_UNUSED);
+ }
+ /*
+ * After we unregistered our callbacks, user space can no longer
+ * offline partially plugged online memory blocks. No need to
+ * worry about them.
+ */
}
- /*
- * 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);
}
/* remove all tracking data - no locking needed */
- vfree(vm->sbm.mb_states);
- vfree(vm->sbm.sb_states);
+ if (vm->in_sbm) {
+ vfree(vm->sbm.mb_states);
+ vfree(vm->sbm.sb_states);
+ } else {
+ vfree(vm->bbm.bb_states);
+ }
/* reset the device and cleanup the queues */
vdev->config->reset(vdev);
projects / linux-2.6-microblaze.git / blobdiff