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: David Hildenbrand <david@redhat.com>
Signed-off-by: Ben Gardon <bgardon@google.com>
Message-Id: <20210518173414.450044-4-bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Ben Gardon 2021-05-18 10:34:10 -07:00 committed by Paolo Bonzini
parent 56dd1019c8
commit ddc12f2a12

View File

@ -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;
}