Re: [PATCH v2 1/4] xen: make logdirty and iommu mutually exclusive

["Roger Pau Monné" <roger.pau@citrix.com>]

On 23/04/14 11:54, Jan Beulich wrote:
>>>> On 23.04.14 at 10:16, <roger.pau@citrix.com> wrote:
>> --- a/xen/arch/x86/mm/hap/hap.c
>> +++ b/xen/arch/x86/mm/hap/hap.c
>> @@ -175,6 +175,15 @@ out:
>>   */
>>  static int hap_enable_log_dirty(struct domain *d, bool_t log_global)
>>  {
>> +
>> +    if ( iommu_enabled && need_iommu(d) && log_global )
> 
> need_iommu() implies iommu_enabled, and hence checking only the
> former ought to be sufficient.
> 
> Also, why do you do this here and in shadow code rather than in
> paging_log_dirty_enable()?

Sight... yes, much better place. Will change it in next version.

>> --- a/xen/drivers/passthrough/iommu.c
>> +++ b/xen/drivers/passthrough/iommu.c
>> @@ -292,7 +292,8 @@ static int assign_device(struct domain *d, u16 seg, u8 
>> bus, u8 devfn)
>>       * enabled for this domain */
>>      if ( unlikely(!need_iommu(d) &&
>>              (d->arch.hvm_domain.mem_sharing_enabled ||
>> -             d->mem_event->paging.ring_page)) )
>> +             d->mem_event->paging.ring_page ||
>> +             paging_mode_log_dirty(d))) )
> 
> I'm afraid that would return true also for non-global log dirty mode.
> This patch series
> http://lists.xenproject.org/archives/html/xen-devel/2014-04/msg02750.html
> (patch 1) introduces a way to know whether global mode is enabled
> - maybe you should base your series on top of that one?

Sure, this series are already on top of Mukesh p2m cleanup patches, I
don't mind rebasing it on top of your series also.

Roger.