Avi Kivity wrote:
> Carsten Otte wrote:
>> Zhang, Xiantao wrote:
>>> Move kvm_vcpu_ioctl_get_dirty_log to arch, and still keep the interface
>>> in common.
>> diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
>> index 45b18e1..3400265 100644
>> --- a/drivers/kvm/kvm_main.c
>> +++ b/drivers/kvm/kvm_main.c
>> @@ -419,19 +419,14 @@ int kvm_vm_ioctl_set_memory_region(struct kvm *kvm,
>> return kvm_set_memory_region(kvm, mem, user_alloc);
>> }
>>
>> -/*
>> - * Get (and clear) the dirty memory log for a memory slot.
>> - */
>> -static int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
>> - struct kvm_dirty_log *log)
>> +int kvm_get_dirty_log(struct kvm *kvm,
>> + struct kvm_dirty_log *log, int *is_dirty)
>>
>> Any reason to remove that comment? It looks helpful to me.
>>
>>
>> {
>> struct kvm_memory_slot *memslot;
>> int r, i;
>> int n;
>> unsigned long any = 0;
>>
>> - mutex_lock(&kvm->lock);
>> -
>> r = -EINVAL;
>> if (log->slot >= KVM_MEMORY_SLOTS)
>> goto out;
>> @@ -450,17 +445,11 @@ static int kvm_vm_ioctl_get_dirty_log(struct kvm
>> *kvm,
>> if (copy_to_user(log->dirty_bitmap, memslot->dirty_bitmap, n))
>> goto out;
>>
>> - /* If nothing is dirty, don't bother messing with page tables. */
>> - if (any) {
>> - kvm_mmu_slot_remove_write_access(kvm, log->slot);
>> - kvm_flush_remote_tlbs(kvm);
>> - memset(memslot->dirty_bitmap, 0, n);
>> - }
>> + if (any)
>> + *is_dirty = 1;
>>
>> r = 0;
>> -
>> out:
>> - mutex_unlock(&kvm->lock);
>> return r;
>> }
>>
>> This split won't work on s390. I think kvm_get_dirty_log should be
>> arch dependent alltogether: we're not going to have a dirty bitmap on
>> s390, we rather rely on our hardware support to update our storage
>> keys accordingly without guest/host intervention required. We'd want
>> to use that, and thus this implementation of kvm_get_dirty_log makes
>> no sense for us. On the other hand, I'd really want to keep the ioctl
>> common, so that guest migration code in userland can be common for all
>> archs.
>
> On the other hand, it will work for all others IIUC. Duplicating it in
> all other archs is not a good idea.
>
> We can special case it using #ifdef ARCH_HAS_KVM_GUEST_DIRTY_BITMAP or
> something.
>
> (hides from the #ifdef police)
Yea, I agree that it would make sense in case it works for power too.
We could have an
#ifdef CONFIG_ARCH_S390
return cool_big_iron_get_dirty_log(args);
#endif
at the beginning of that function. It would'nt hurt readability too much.
Hollis? Christian? How about ppc?
-------------------------------------------------------------------------
This SF.net email is sponsored by: Microsoft
Defy all challenges. Microsoft(R) Visual Studio 2005.
http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/
_______________________________________________
kvm-devel mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/kvm-devel
