diff options
| -rw-r--r-- | drivers/virtio/virtio_mem.c | 103 |
1 files changed, 57 insertions, 46 deletions
diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c index c0e6ea6244e4..d54bb34a7ed8 100644 --- a/drivers/virtio/virtio_mem.c +++ b/drivers/virtio/virtio_mem.c @@ -1453,8 +1453,8 @@ static int virtio_mem_bbm_plug_bb(struct virtio_mem *vm, unsigned long bb_id) * * Note: can fail after some subblocks were unplugged. */ -static int virtio_mem_sbm_unplug_any_sb(struct virtio_mem *vm, - unsigned long mb_id, uint64_t *nb_sb) +static int virtio_mem_sbm_unplug_any_sb_raw(struct virtio_mem *vm, + unsigned long mb_id, uint64_t *nb_sb) { int sb_id, count; int rc; @@ -1496,7 +1496,7 @@ static int virtio_mem_sbm_unplug_mb(struct virtio_mem *vm, unsigned long mb_id) { uint64_t nb_sb = vm->sbm.sbs_per_mb; - return virtio_mem_sbm_unplug_any_sb(vm, mb_id, &nb_sb); + return virtio_mem_sbm_unplug_any_sb_raw(vm, mb_id, &nb_sb); } /* @@ -1806,7 +1806,7 @@ static int virtio_mem_sbm_unplug_any_sb_offline(struct virtio_mem *vm, { int rc; - rc = virtio_mem_sbm_unplug_any_sb(vm, mb_id, nb_sb); + rc = virtio_mem_sbm_unplug_any_sb_raw(vm, mb_id, nb_sb); /* some subblocks might have been unplugged even on failure */ if (!virtio_mem_sbm_test_sb_plugged(vm, mb_id, 0, vm->sbm.sbs_per_mb)) @@ -1929,11 +1929,46 @@ unplugged: return 0; } +/* + * Unplug the desired number of plugged subblocks of a memory block that is + * already added to Linux. Will skip subblock of online memory blocks that are + * busy (by the OS). Will fail if any subblock that's not busy cannot get + * unplugged. + * + * 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_sbm_unplug_any_sb(struct virtio_mem *vm, + unsigned long mb_id, + uint64_t *nb_sb) +{ + const int old_state = virtio_mem_sbm_get_mb_state(vm, mb_id); + + switch (old_state) { + case VIRTIO_MEM_SBM_MB_ONLINE_PARTIAL: + case VIRTIO_MEM_SBM_MB_ONLINE: + return virtio_mem_sbm_unplug_any_sb_online(vm, mb_id, nb_sb); + case VIRTIO_MEM_SBM_MB_OFFLINE_PARTIAL: + case VIRTIO_MEM_SBM_MB_OFFLINE: + return virtio_mem_sbm_unplug_any_sb_offline(vm, mb_id, nb_sb); + } + return -EINVAL; +} + static int virtio_mem_sbm_unplug_request(struct virtio_mem *vm, uint64_t diff) { + const int mb_states[] = { + VIRTIO_MEM_SBM_MB_OFFLINE_PARTIAL, + VIRTIO_MEM_SBM_MB_OFFLINE, + VIRTIO_MEM_SBM_MB_ONLINE_PARTIAL, + VIRTIO_MEM_SBM_MB_ONLINE, + }; uint64_t nb_sb = diff / vm->sbm.sb_size; unsigned long mb_id; - int rc; + int rc, i; if (!nb_sb) return 0; @@ -1945,47 +1980,23 @@ static int virtio_mem_sbm_unplug_request(struct virtio_mem *vm, uint64_t diff) */ mutex_lock(&vm->hotplug_mutex); - /* Try to unplug subblocks of partially plugged offline blocks. */ - virtio_mem_sbm_for_each_mb_rev(vm, mb_id, - VIRTIO_MEM_SBM_MB_OFFLINE_PARTIAL) { - rc = virtio_mem_sbm_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_sbm_for_each_mb_rev(vm, mb_id, VIRTIO_MEM_SBM_MB_OFFLINE) { - rc = virtio_mem_sbm_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_sbm_for_each_mb_rev(vm, mb_id, - VIRTIO_MEM_SBM_MB_ONLINE_PARTIAL) { - rc = virtio_mem_sbm_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_sbm_for_each_mb_rev(vm, mb_id, VIRTIO_MEM_SBM_MB_ONLINE) { - rc = virtio_mem_sbm_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); + /* + * We try unplug from partially plugged blocks first, to try removing + * whole memory blocks along with metadata. + */ + for (i = 0; i < ARRAY_SIZE(mb_states); i++) { + virtio_mem_sbm_for_each_mb_rev(vm, mb_id, mb_states[i]) { + rc = virtio_mem_sbm_unplug_any_sb(vm, mb_id, &nb_sb); + if (rc || !nb_sb) + goto out_unlock; + mutex_unlock(&vm->hotplug_mutex); + cond_resched(); + mutex_lock(&vm->hotplug_mutex); + } + if (!unplug_online && i == 1) { + mutex_unlock(&vm->hotplug_mutex); + return 0; + } } mutex_unlock(&vm->hotplug_mutex); |