Am 13/09/2022 um 04:30 schrieb Yang, Weijiang:
>
> On 9/9/2022 6:45 PM, Emanuele Giuseppe Esposito wrote:
>> When kvm_vm_ioctl_set_memory_region_list() is invoked, we need
>> to make sure that all memslots are updated in the inactive list
>> and then swap (preferreably only once) the lists, so that all
>> changes are visible immediately.
> [...]
>> +static int kvm_vm_ioctl_set_memory_region_list(struct kvm *kvm,
>> + struct kvm_userspace_memory_region_list *list,
>> + struct kvm_userspace_memory_region_entry __user *mem_arg)
>> +{
>> + struct kvm_userspace_memory_region_entry *mem, *m_iter;
>> + struct kvm_userspace_memory_region *mem_region;
>> + struct kvm_internal_memory_region_list *batch, *b_iter;
>> + int i, r = 0;
>> + bool *as_to_swap;
>> +
>> + /* TODO: limit the number of mem to a max? */
>> +
>> + if (!list->nent)
>> + return r;
>> +
>> + mem = vmemdup_user(mem_arg, array_size(sizeof(*mem), list->nent));
>> + if (IS_ERR(mem)) {
>> + r = PTR_ERR(mem);
>> + goto out;
>> + }
>
> IMO, it's more natural to dup the user memory at the first place, i.e.,
> kvm_vm_ioctl,
>
> it also makes the outlets shorter.
>
I followed the same pattern as kvm_vcpu_ioctl_set_cpuid2, which performs
the user memory dup inside the call :)
I see your point but I guess it's better to keep all ioctl
implementations similar.
Thank you,
Emanuele
