virito-mem: subblock states are specific to Sub Block Mode (SBM)

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>
Link: https://lore.kernel.org/r/20201112133815.13332-20-david@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c
index c6cc301..851cddf 100644 (file)
--- 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 @@ unplugged:
         * 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);