Re: [PATCH v3 05/13] xen/passthrough: rework dom0_pvh_reqs to use it also on ARM

[Julien Grall <julien.grall@linaro.org>]

Hi Ian,

On 03/18/2014 04:22 PM, Ian Campbell wrote:
> On Tue, 2014-03-11 at 15:49 +0000, Julien Grall wrote:
>> DOM0 on ARM will have the same requirements as DOM0 PVH when iommu is enabled.
>> Both PVH and ARM guest has paging mode translate enabled, so Xen can use it
>> to know if it needs to check the requirements.
>>
>> Rename the function and remove "pvh" word in the panic message.
>>
>> Signed-off-by: Julien Grall <julien.grall@linaro.org>
>> Acked-by: Jan Beulich <jbeulich@suse.com>
>> Cc: Xiantao Zhang <xiantao.zhang@intel.com>
>>
>> ---
>>     Changes in v2:
>>         - IOMMU can be disabled on ARM if the platform doesn't have
>>         IOMMU.
>> ---
>>  xen/drivers/passthrough/iommu.c |   13 ++++++++-----
>>  1 file changed, 8 insertions(+), 5 deletions(-)
>>
>> diff --git a/xen/drivers/passthrough/iommu.c b/xen/drivers/passthrough/iommu.c
>> index c70165a..3c63f87 100644
>> --- a/xen/drivers/passthrough/iommu.c
>> +++ b/xen/drivers/passthrough/iommu.c
>> @@ -130,13 +130,17 @@ int iommu_domain_init(struct domain *d)
>>      return hd->platform_ops->init(d);
>>  }
>>  
>> -static __init void check_dom0_pvh_reqs(struct domain *d)
>> +static __init void check_dom0_reqs(struct domain *d)
>>  {
>> -    if ( !iommu_enabled )
>> +    if ( !paging_mode_translate(d) )
>> +        return;
>> +
>> +    if ( is_pvh_domain(d) && !iommu_enabled )
> 
> Is is_pvh_domain going to be exposed to common code on ARM?

It will be exposed to common code. For now is_pvh_domain is part of
xen/sched.h, do you plan to move it in asm-x86?

> Or would a arch_check_dom0_reqs be useful here?

I will update patch #7 to create this function.

>>          panic("Presently, iommu must be enabled for pvh dom0\n");
>>  
>>      if ( iommu_passthrough )
>> -        panic("For pvh dom0, dom0-passthrough must not be enabled\n");
>> +        panic("Dom0 uses translate paging mode, dom0-passthrough must not be "
> 
> "paging translated mode" reads more natural to me.

I will change in the next version.

Regards,

-- 
Julien Grall