> Let's factor out the core logic, to be reused soon.
>
> Cc: Paolo Bonzini <pbonz...@redhat.com>
> Cc: "Michael S. Tsirkin" <m...@redhat.com>
> Cc: Alex Williamson <alex.william...@redhat.com>
> Cc: Dr. David Alan Gilbert <dgilb...@redhat.com>
> Cc: Igor Mammedov <imamm...@redhat.com>
> Cc: Pankaj Gupta <pankaj.gupta.li...@gmail.com>
> Cc: Peter Xu <pet...@redhat.com>
> Cc: Auger Eric <eric.au...@redhat.com>
> Cc: Wei Yang <richard.weiy...@linux.alibaba.com>
> Cc: teawater <teawat...@linux.alibaba.com>
> Cc: Marek Kedzierski <mkedz...@redhat.com>
> Signed-off-by: David Hildenbrand <da...@redhat.com>
> ---
> hw/virtio/virtio-mem.c | 86 ++++++++++++++++++++++++------------------
> 1 file changed, 49 insertions(+), 37 deletions(-)
>
> diff --git a/hw/virtio/virtio-mem.c b/hw/virtio/virtio-mem.c
> index 655824ff81..471e464171 100644
> --- a/hw/virtio/virtio-mem.c
> +++ b/hw/virtio/virtio-mem.c
> @@ -145,6 +145,33 @@ static bool virtio_mem_is_busy(void)
> return migration_in_incoming_postcopy() || !migration_is_idle();
> }
>
> +typedef int (*virtio_mem_range_cb)(const VirtIOMEM *vmem, void *arg,
> + uint64_t offset, uint64_t size);
> +
> +static int virtio_mem_for_each_unplugged_range(const VirtIOMEM *vmem, void
> *arg,
> + virtio_mem_range_cb cb)
> +{
> + unsigned long first_zero_bit, last_zero_bit;
> + uint64_t offset, size;
> + int ret = 0;
> +
> + first_zero_bit = find_first_zero_bit(vmem->bitmap, vmem->bitmap_size);
> + while (first_zero_bit < vmem->bitmap_size) {
> + offset = first_zero_bit * vmem->block_size;
> + last_zero_bit = find_next_bit(vmem->bitmap, vmem->bitmap_size,
> + first_zero_bit + 1) - 1;
> + size = (last_zero_bit - first_zero_bit + 1) * vmem->block_size;
> +
> + ret = cb(vmem, arg, offset, size);
> + if (ret) {
> + break;
> + }
> + first_zero_bit = find_next_zero_bit(vmem->bitmap, vmem->bitmap_size,
> + last_zero_bit + 2);
> + }
> + return ret;
> +}
> +
> static bool virtio_mem_test_bitmap(VirtIOMEM *vmem, uint64_t start_gpa,
> uint64_t size, bool plugged)
> {
> @@ -594,33 +621,27 @@ static void virtio_mem_device_unrealize(DeviceState
> *dev)
> ram_block_discard_require(false);
> }
>
> -static int virtio_mem_restore_unplugged(VirtIOMEM *vmem)
> +static int virtio_mem_discard_range_cb(const VirtIOMEM *vmem, void *arg,
> + uint64_t offset, uint64_t size)
> {
> RAMBlock *rb = vmem->memdev->mr.ram_block;
> - unsigned long first_zero_bit, last_zero_bit;
> - uint64_t offset, length;
> int ret;
>
> - /* Find consecutive unplugged blocks and discard the consecutive range.
> */
> - first_zero_bit = find_first_zero_bit(vmem->bitmap, vmem->bitmap_size);
> - while (first_zero_bit < vmem->bitmap_size) {
> - offset = first_zero_bit * vmem->block_size;
> - last_zero_bit = find_next_bit(vmem->bitmap, vmem->bitmap_size,
> - first_zero_bit + 1) - 1;
> - length = (last_zero_bit - first_zero_bit + 1) * vmem->block_size;
> -
> - ret = ram_block_discard_range(rb, offset, length);
> - if (ret) {
> - error_report("Unexpected error discarding RAM: %s",
> - strerror(-ret));
> - return -EINVAL;
> - }
> - first_zero_bit = find_next_zero_bit(vmem->bitmap, vmem->bitmap_size,
> - last_zero_bit + 2);
> + ret = ram_block_discard_range(rb, offset, size);
> + if (ret) {
> + error_report("Unexpected error discarding RAM: %s", strerror(-ret));
> + return -EINVAL;
> }
> return 0;
> }
>
> +static int virtio_mem_restore_unplugged(VirtIOMEM *vmem)
> +{
> + /* Make sure all memory is really discarded after migration. */
> + return virtio_mem_for_each_unplugged_range(vmem, NULL,
> + virtio_mem_discard_range_cb);
> +}
> +
> static int virtio_mem_post_load(void *opaque, int version_id)
> {
> if (migration_in_incoming_postcopy()) {
> @@ -872,28 +893,19 @@ static void virtio_mem_set_block_size(Object *obj,
> Visitor *v, const char *name,
> vmem->block_size = value;
> }
>
> -static void virtio_mem_precopy_exclude_unplugged(VirtIOMEM *vmem)
> +static int virtio_mem_precopy_exclude_range_cb(const VirtIOMEM *vmem, void
> *arg,
> + uint64_t offset, uint64_t
> size)
> {
> void * const host = qemu_ram_get_host_addr(vmem->memdev->mr.ram_block);
> - unsigned long first_zero_bit, last_zero_bit;
> - uint64_t offset, length;
>
> - /*
> - * Find consecutive unplugged blocks and exclude them from migration.
> - *
> - * Note: Blocks cannot get (un)plugged during precopy, no locking needed.
> - */
> - first_zero_bit = find_first_zero_bit(vmem->bitmap, vmem->bitmap_size);
> - while (first_zero_bit < vmem->bitmap_size) {
> - offset = first_zero_bit * vmem->block_size;
> - last_zero_bit = find_next_bit(vmem->bitmap, vmem->bitmap_size,
> - first_zero_bit + 1) - 1;
> - length = (last_zero_bit - first_zero_bit + 1) * vmem->block_size;
> + qemu_guest_free_page_hint(host + offset, size);
> + return 0;
> +}
>
> - qemu_guest_free_page_hint(host + offset, length);
> - first_zero_bit = find_next_zero_bit(vmem->bitmap, vmem->bitmap_size,
> - last_zero_bit + 2);
> - }
> +static void virtio_mem_precopy_exclude_unplugged(VirtIOMEM *vmem)
> +{
> + virtio_mem_for_each_unplugged_range(vmem, NULL,
> + virtio_mem_precopy_exclude_range_cb);
> }
>
> static int virtio_mem_precopy_notify(NotifierWithReturn *n, void *data)
Reviewed-by: Pankaj Gupta <pankaj.gu...@cloud.ionos.com>
