[PATCH v2 19/29] virito-mem: subblock states are specific to Sub Block Mode (SBM)

David Hildenbrand
2020-11-12T13:39:34Z

Let's rename and move accordingly. While at it, rename sb_bitmap to
"sb_states".

Reviewed-by: Wei Yang <richard.weiyang@linux.alibaba.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
drivers/virtio/virtio_mem.c | 132 +++++++++++++++++++-----------------
1 file changed, 69 insertions(+), 63 deletions(-)

diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c
index c6cc301c78e1..851cddf5c606 100644
--- a/drivers/virtio/virtio_mem.c
+++ b/drivers/virtio/virtio_mem.c
@@ -137,17 +137,23 @@ struct virtio_mem {
* memory in one 4 KiB page.
*/
uint8_t *mb_states;
- } sbm;

- /*
- * $nb_sb_per_mb bit per memory block. Handled similar to sbm.mb_states.
- *
- * With 4MB subblocks, we manage 128GB of memory in one page.
- */
- unsigned long *sb_bitmap;
+ /*
+ * 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;

/*
- * Mutex that protects the sbm.mb_count, sbm.mb_states, and sb_bitmap.
+ * Mutex that protects the sbm.mb_count, sbm.mb_states, and
+ * sbm.sb_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
@@ -323,8 +329,8 @@ static int virtio_mem_sbm_mb_states_prepare_next_mb(struct virtio_mem *vm)
* Calculate the bit number in the subblock bitmap for the given subblock
* inside the given memory block.
*/
-static int virtio_mem_sb_bitmap_bit_nr(struct virtio_mem *vm,
- unsigned long mb_id, int sb_id)
+static int virtio_mem_sbm_sb_state_bit_nr(struct virtio_mem *vm,
+ unsigned long mb_id, int sb_id)
{
return (mb_id - vm->first_mb_id) * vm->nb_sb_per_mb + sb_id;
}
@@ -334,13 +340,13 @@ static int virtio_mem_sb_bitmap_bit_nr(struct virtio_mem *vm,
*
* Will not modify the state of the memory block.
*/
-static void virtio_mem_mb_set_sb_plugged(struct virtio_mem *vm,
- unsigned long mb_id, int sb_id,
- int count)
+static void virtio_mem_sbm_set_sb_plugged(struct virtio_mem *vm,
+ unsigned long mb_id, int sb_id,
+ int count)
{
- const int bit = virtio_mem_sb_bitmap_bit_nr(vm, mb_id, sb_id);
+ const int bit = virtio_mem_sbm_sb_state_bit_nr(vm, mb_id, sb_id);

- __bitmap_set(vm->sb_bitmap, bit, count);
+ __bitmap_set(vm->sbm.sb_states, bit, count);
}

/*
@@ -348,86 +354,87 @@ static void virtio_mem_mb_set_sb_plugged(struct virtio_mem *vm,
*
* Will not modify the state of the memory block.
*/
-static void virtio_mem_mb_set_sb_unplugged(struct virtio_mem *vm,
- unsigned long mb_id, int sb_id,
- int count)
+static void virtio_mem_sbm_set_sb_unplugged(struct virtio_mem *vm,
+ unsigned long mb_id, int sb_id,
+ int count)
{
- const int bit = virtio_mem_sb_bitmap_bit_nr(vm, mb_id, sb_id);
+ const int bit = virtio_mem_sbm_sb_state_bit_nr(vm, mb_id, sb_id);

- __bitmap_clear(vm->sb_bitmap, bit, count);
+ __bitmap_clear(vm->sbm.sb_states, bit, count);
}

/*
* Test if all selected subblocks are plugged.
*/
-static bool virtio_mem_mb_test_sb_plugged(struct virtio_mem *vm,
- unsigned long mb_id, int sb_id,
- int count)
+static bool virtio_mem_sbm_test_sb_plugged(struct virtio_mem *vm,
+ unsigned long mb_id, int sb_id,
+ int count)
{
- const int bit = virtio_mem_sb_bitmap_bit_nr(vm, mb_id, sb_id);
+ const int bit = virtio_mem_sbm_sb_state_bit_nr(vm, mb_id, sb_id);

if (count == 1)
- return test_bit(bit, vm->sb_bitmap);
+ return test_bit(bit, vm->sbm.sb_states);

/* TODO: Helper similar to bitmap_set() */
- return find_next_zero_bit(vm->sb_bitmap, bit + count, bit) >=
+ return find_next_zero_bit(vm->sbm.sb_states, bit + count, bit) >=
bit + count;
}

/*
* Test if all selected subblocks are unplugged.
*/
-static bool virtio_mem_mb_test_sb_unplugged(struct virtio_mem *vm,
- unsigned long mb_id, int sb_id,
- int count)
+static bool virtio_mem_sbm_test_sb_unplugged(struct virtio_mem *vm,
+ unsigned long mb_id, int sb_id,
+ int count)
{
- const int bit = virtio_mem_sb_bitmap_bit_nr(vm, mb_id, sb_id);
+ const int bit = virtio_mem_sbm_sb_state_bit_nr(vm, mb_id, sb_id);

/* TODO: Helper similar to bitmap_set() */
- return find_next_bit(vm->sb_bitmap, bit + count, bit) >= bit + count;
+ return find_next_bit(vm->sbm.sb_states, bit + count, bit) >=
+ bit + count;
}

/*
* Find the first unplugged subblock. Returns vm->nb_sb_per_mb in case there is
* none.
*/
-static int virtio_mem_mb_first_unplugged_sb(struct virtio_mem *vm,
+static int virtio_mem_sbm_first_unplugged_sb(struct virtio_mem *vm,
unsigned long mb_id)
{
- const int bit = virtio_mem_sb_bitmap_bit_nr(vm, mb_id, 0);
+ const int bit = virtio_mem_sbm_sb_state_bit_nr(vm, mb_id, 0);

- return find_next_zero_bit(vm->sb_bitmap, bit + vm->nb_sb_per_mb, bit) -
- bit;
+ return find_next_zero_bit(vm->sbm.sb_states,
+ bit + vm->nb_sb_per_mb, bit) - bit;
}

/*
* Prepare the subblock bitmap for the next memory block.
*/
-static int virtio_mem_sb_bitmap_prepare_next_mb(struct virtio_mem *vm)
+static int virtio_mem_sbm_sb_states_prepare_next_mb(struct virtio_mem *vm)
{
const unsigned long old_nb_mb = vm->next_mb_id - vm->first_mb_id;
const unsigned long old_nb_bits = old_nb_mb * vm->nb_sb_per_mb;
const unsigned long new_nb_bits = (old_nb_mb + 1) * vm->nb_sb_per_mb;
int old_pages = PFN_UP(BITS_TO_LONGS(old_nb_bits) * sizeof(long));
int new_pages = PFN_UP(BITS_TO_LONGS(new_nb_bits) * sizeof(long));
- unsigned long *new_sb_bitmap, *old_sb_bitmap;
+ unsigned long *new_bitmap, *old_bitmap;

- if (vm->sb_bitmap && old_pages == new_pages)
+ if (vm->sbm.sb_states && old_pages == new_pages)
return 0;

- new_sb_bitmap = vzalloc(new_pages * PAGE_SIZE);
- if (!new_sb_bitmap)
+ new_bitmap = vzalloc(new_pages * PAGE_SIZE);
+ if (!new_bitmap)
return -ENOMEM;

mutex_lock(&vm->hotplug_mutex);
- if (new_sb_bitmap)
- memcpy(new_sb_bitmap, vm->sb_bitmap, old_pages * PAGE_SIZE);
+ if (new_bitmap)
+ memcpy(new_bitmap, vm->sbm.sb_states, old_pages * PAGE_SIZE);

- old_sb_bitmap = vm->sb_bitmap;
- vm->sb_bitmap = new_sb_bitmap;
+ old_bitmap = vm->sbm.sb_states;
+ vm->sbm.sb_states = new_bitmap;
mutex_unlock(&vm->hotplug_mutex);

- vfree(old_sb_bitmap);
+ vfree(old_bitmap);
return 0;
}

@@ -638,7 +645,7 @@ static void virtio_mem_notify_going_offline(struct virtio_mem *vm,
int sb_id;

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))
+ if (virtio_mem_sbm_test_sb_plugged(vm, mb_id, sb_id, 1))
continue;
pfn = PFN_DOWN(virtio_mem_mb_id_to_phys(mb_id) +
sb_id * vm->subblock_size);
@@ -654,7 +661,7 @@ static void virtio_mem_notify_cancel_offline(struct virtio_mem *vm,
int sb_id;

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))
+ if (virtio_mem_sbm_test_sb_plugged(vm, mb_id, sb_id, 1))
continue;
pfn = PFN_DOWN(virtio_mem_mb_id_to_phys(mb_id) +
sb_id * vm->subblock_size);
@@ -944,7 +951,7 @@ static void virtio_mem_online_page_cb(struct page *page, unsigned int order)
* If plugged, online the pages, otherwise, set them fake
* offline (PageOffline).
*/
- if (virtio_mem_mb_test_sb_plugged(vm, mb_id, sb_id, 1))
+ if (virtio_mem_sbm_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,
@@ -1102,7 +1109,7 @@ static int virtio_mem_mb_plug_sb(struct virtio_mem *vm, unsigned long mb_id,

rc = virtio_mem_send_plug_request(vm, addr, size);
if (!rc)
- virtio_mem_mb_set_sb_plugged(vm, mb_id, sb_id, count);
+ virtio_mem_sbm_set_sb_plugged(vm, mb_id, sb_id, count);
return rc;
}

@@ -1120,7 +1127,7 @@ static int virtio_mem_mb_unplug_sb(struct virtio_mem *vm, unsigned long mb_id,

rc = virtio_mem_send_unplug_request(vm, addr, size);
if (!rc)
- virtio_mem_mb_set_sb_unplugged(vm, mb_id, sb_id, count);
+ virtio_mem_sbm_set_sb_unplugged(vm, mb_id, sb_id, count);
return rc;
}

@@ -1143,14 +1150,14 @@ static int virtio_mem_mb_unplug_any_sb(struct virtio_mem *vm,
while (*nb_sb) {
/* Find the next candidate subblock */
while (sb_id >= 0 &&
- virtio_mem_mb_test_sb_unplugged(vm, mb_id, sb_id, 1))
+ virtio_mem_sbm_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)) {
+ virtio_mem_sbm_test_sb_plugged(vm, mb_id, sb_id - 1, 1)) {
count++;
sb_id--;
}
@@ -1196,7 +1203,7 @@ static int virtio_mem_prepare_next_mb(struct virtio_mem *vm,
return rc;

/* Resize the subblock bitmap if required. */
- rc = virtio_mem_sb_bitmap_prepare_next_mb(vm);
+ rc = virtio_mem_sbm_sb_states_prepare_next_mb(vm);
if (rc)
return rc;

@@ -1281,14 +1288,13 @@ static int virtio_mem_mb_plug_any_sb(struct virtio_mem *vm, unsigned long mb_id,
return -EINVAL;

while (*nb_sb) {
- sb_id = virtio_mem_mb_first_unplugged_sb(vm, mb_id);
+ sb_id = virtio_mem_sbm_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))
+ !virtio_mem_sbm_test_sb_plugged(vm, mb_id, sb_id + count, 1))
count++;

rc = virtio_mem_mb_plug_sb(vm, mb_id, sb_id, count);
@@ -1305,7 +1311,7 @@ static int virtio_mem_mb_plug_any_sb(struct virtio_mem *vm, unsigned long mb_id,
virtio_mem_fake_online(pfn, nr_pages);
}

- if (virtio_mem_mb_test_sb_plugged(vm, mb_id, 0, vm->nb_sb_per_mb)) {
+ if (virtio_mem_sbm_test_sb_plugged(vm, mb_id, 0, vm->nb_sb_per_mb)) {
if (online)
virtio_mem_sbm_set_mb_state(vm, mb_id,
VIRTIO_MEM_SBM_MB_ONLINE);
@@ -1405,13 +1411,13 @@ static int virtio_mem_mb_unplug_any_sb_offline(struct virtio_mem *vm,
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))
+ if (!virtio_mem_sbm_test_sb_plugged(vm, mb_id, 0, vm->nb_sb_per_mb))
virtio_mem_sbm_set_mb_state(vm, mb_id,
VIRTIO_MEM_SBM_MB_OFFLINE_PARTIAL);
if (rc)
return rc;

- if (virtio_mem_mb_test_sb_unplugged(vm, mb_id, 0, vm->nb_sb_per_mb)) {
+ if (virtio_mem_sbm_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
@@ -1480,7 +1486,7 @@ static int virtio_mem_mb_unplug_any_sb_online(struct virtio_mem *vm,

/* 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)) {
+ virtio_mem_sbm_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) {
@@ -1494,7 +1500,7 @@ static int virtio_mem_mb_unplug_any_sb_online(struct virtio_mem *vm,
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))
+ !virtio_mem_sbm_test_sb_plugged(vm, mb_id, sb_id, 1))
sb_id--;
if (sb_id < 0)
break;
@@ -1513,7 +1519,7 @@ static int virtio_mem_mb_unplug_any_sb_online(struct virtio_mem *vm,
* 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)) {
+ if (virtio_mem_sbm_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);
@@ -2035,7 +2041,7 @@ static void virtio_mem_remove(struct virtio_device *vdev)

/* remove all tracking data - no locking needed */
vfree(vm->sbm.mb_states);
- vfree(vm->sb_bitmap);
+ vfree(vm->sbm.sb_states);

/* reset the device and cleanup the queues */
vdev->config->reset(vdev);
--
2.26.2