Commit ddc12f2a authored by Ben Gardon's avatar Ben Gardon Committed by Paolo Bonzini
Browse files

KVM: mmu: Refactor memslot copy 



Factor out copying kvm_memslots from allocating the memory for new ones
in preparation for adding a new lock to protect the arch-specific fields
of the memslots.

No functional change intended.

Reviewed-by: default avatarDavid Hildenbrand <david@redhat.com>
Signed-off-by: default avatarBen Gardon <bgardon@google.com>
Message-Id: <20210518173414.450044-4-bgardon@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 56dd1019

virt/kvm/kvm_main.c

+16 −7
Original line number Diff line number Diff line
@@ -1307,6 +1307,18 @@ static struct kvm_memslots *install_new_memslots(struct kvm *kvm, 
	return old_memslots;

}



static size_t kvm_memslots_size(int slots)

{

	return sizeof(struct kvm_memslots) +

	       (sizeof(struct kvm_memory_slot) * slots);

}



static void kvm_copy_memslots(struct kvm_memslots *to,

			      struct kvm_memslots *from)

{

	memcpy(to, from, kvm_memslots_size(from->used_slots));

}



/*

 * Note, at a minimum, the current number of used slots must be allocated, even

 * when deleting a memslot, as we need a complete duplicate of the memslots for
@@ -1316,19 +1328,16 @@ static struct kvm_memslots *kvm_dup_memslots(struct kvm_memslots *old, 
					     enum kvm_mr_change change)

{

	struct kvm_memslots *slots;

	size_t old_size, new_size;



	old_size = sizeof(struct kvm_memslots) +

		   (sizeof(struct kvm_memory_slot) * old->used_slots);

	size_t new_size;



	if (change == KVM_MR_CREATE)

		new_size = old_size + sizeof(struct kvm_memory_slot);

		new_size = kvm_memslots_size(old->used_slots + 1);

	else

		new_size = old_size;

		new_size = kvm_memslots_size(old->used_slots);



	slots = kvzalloc(new_size, GFP_KERNEL_ACCOUNT);

	if (likely(slots))

		memcpy(slots, old, old_size);

		kvm_copy_memslots(slots, old);



	return slots;

}