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virtio-mem: Big Block Mode (BBM) memory hotplug

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Currently, we do not support device block sizes that exceed the Linux
memory block size. For example, having a device block size of 1 GiB (e.g.,
gigantic pages in the hypervisor) won't work with 128 MiB Linux memory
blocks.

Let's implement Big Block Mode (BBM), whereby we add/remove at least
one Linux memory block at a time. With a 1 GiB device block size, a Big
Block (BB) will cover 8 Linux memory blocks.

We'll keep registering the online_page_callback machinery, it will be used
for safe memory hotunplug in BBM next.

Note: BBM is properly prepared for variable-sized Linux memory
blocks that we might see in the future. So we won't care how many Linux
memory blocks a big block actually spans, and how the memory notifier is
called.

Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20201112133815.13332-26-david@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
David Hildenbrand 2020-11-12 14:38:11 +01:00 committed by Michael S. Tsirkin
parent 01afdee29a
commit 4ba50cd335
1 changed files with 437 additions and 115 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

552
drivers/virtio/virtio_mem.c
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@ -30,12 +30,18 @@ MODULE_PARM_DESC(unplug_online, "Try to unplug online memory");
/*
* 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
@ -61,6 +67,19 @@ enum virtio_mem_sbm_mb_state {
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,
VIRTIO_MEM_BBM_BB_COUNT
};
struct virtio_mem {
struct virtio_device *vdev;
@ -113,47 +132,70 @@ struct virtio_mem {
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;
/* If set, the driver is in SBM, otherwise in BBM. */
bool in_sbm;
/* The subblock size. */
uint64_t sb_size;
/* The number of subblocks per Linux memory block. */
uint32_t sbs_per_mb;
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;
/* Summary of all memory block states. */
unsigned long mb_count[VIRTIO_MEM_SBM_MB_COUNT];
/* The subblock size. */
uint64_t sb_size;
/* The number of subblocks per Linux memory block. */
uint32_t sbs_per_mb;
/*
* 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;
/* Summary of all memory block states. */
unsigned long mb_count[VIRTIO_MEM_SBM_MB_COUNT];
/*
* 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;
/*
* 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
@ -247,6 +289,24 @@ static unsigned long virtio_mem_mb_id_to_phys(unsigned long mb_id)
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.
*/
@ -259,6 +319,67 @@ static unsigned long virtio_mem_phys_to_sb_id(struct virtio_mem *vm,
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)
/*
* Set the state of a memory block, taking care of the state counter.
*/
@ -502,6 +623,17 @@ static int virtio_mem_sbm_add_mb(struct virtio_mem *vm, unsigned long mb_id)
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.
@ -729,20 +861,33 @@ static int virtio_mem_memory_notifier_cb(struct notifier_block *nb,
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
@ -761,7 +906,8 @@ static int virtio_mem_memory_notifier_cb(struct notifier_block *nb,
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);
break;
case MEM_GOING_ONLINE:
mutex_lock(&vm->hotplug_mutex);
@ -771,10 +917,12 @@ static int virtio_mem_memory_notifier_cb(struct notifier_block *nb,
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);
/*
@ -788,7 +936,8 @@ static int virtio_mem_memory_notifier_cb(struct notifier_block *nb,
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);
/*
@ -807,7 +956,8 @@ static int virtio_mem_memory_notifier_cb(struct notifier_block *nb,
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);
vm->hotplug_active = false;
mutex_unlock(&vm->hotplug_mutex);
break;
@ -978,27 +1128,29 @@ static void virtio_mem_fake_offline_cancel_offline(unsigned long pfn,
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 {
do_online = true;
}
if (do_online)
generic_online_page(page, order);
else
virtio_mem_set_fake_offline(PFN_DOWN(addr), 1 << order,
@ -1178,6 +1330,32 @@ static int virtio_mem_sbm_unplug_sb(struct virtio_mem *vm, unsigned long mb_id,
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
@ -1363,10 +1541,7 @@ static int virtio_mem_sbm_plug_any_sb(struct virtio_mem *vm,
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;
@ -1433,6 +1608,112 @@ out_unlock:
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).
@ -1571,10 +1852,7 @@ unplugged:
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;
@ -1640,20 +1918,42 @@ out_unlock:
return rc;
}
/*
* 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 -EBUSY;
}
/*
* 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);
}
@ -1679,7 +1979,13 @@ static void virtio_mem_refresh_config(struct virtio_mem *vm)
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,
@ -1802,6 +2108,7 @@ static int virtio_mem_init_vq(struct virtio_mem *vm)
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) {
@ -1834,16 +2141,6 @@ static int virtio_mem_init(struct virtio_mem *vm)
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,
@ -1863,20 +2160,35 @@ static int virtio_mem_init(struct virtio_mem *vm)
* - 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);
/* 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;
if (sb_size < memory_block_size_bytes()) {
/* 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 = vm->device_block_size;
vm->bbm.first_bb_id = virtio_mem_phys_to_bb_id(vm, 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);
@ -1884,8 +2196,12 @@ static int virtio_mem_init(struct virtio_mem *vm)
(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);
@ -2042,22 +2358,24 @@ static void virtio_mem_remove(struct virtio_device *vdev)
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_sbm_remove_mb(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);
@ -2076,8 +2394,12 @@ static void virtio_mem_remove(struct virtio_device *vdev)
}
/* 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);