Re: [PATCH 5/7] memory: Register the RamDiscardManager instance upon guest_memfd creation

Zhao Liu
2025-01-09T07:55:31Z

> #ifdef CONFIG_FALLOCATE_PUNCH_HOLE
> @@ -1885,6 +1886,9 @@ static void ram_block_add(RAMBlock *new_block, Error **errp)
> qemu_mutex_unlock_ramlist();
> goto out_free;
> }
> +
> + GuestMemfdManager *gmm = GUEST_MEMFD_MANAGER(object_new(TYPE_GUEST_MEMFD_MANAGER));
> + guest_memfd_manager_realize(gmm, new_block->mr, new_block->mr->size);

realize & unrealize are usually used for QDev. I think it's not good to use
*realize and *unrealize here.

Why about "guest_memfd_manager_attach_ram"?

In addition, it seems the third parameter is unnecessary and we can access
MemoryRegion.size directly in guest_memfd_manager_realize().

> }
>
> ram_size = (new_block->offset + new_block->max_length) >> TARGET_PAGE_BITS;
> @@ -2139,6 +2143,9 @@ static void reclaim_ramblock(RAMBlock *block)
>
> if (block->guest_memfd >= 0) {
> close(block->guest_memfd);
> + GuestMemfdManager *gmm = GUEST_MEMFD_MANAGER(block->mr->rdm);
> + guest_memfd_manager_unrealize(gmm);

Similiarly, what about "guest_memfd_manager_unattach_ram"?

> + object_unref(OBJECT(gmm));
> ram_block_discard_require(false);
> }
>

Regards,
Zhao