[PATCH 2/4] amd iommu: Large io page support - parameter

[PATCH 2/4] amd iommu: Large io page support - parameter

[Wei Wang2]

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Add a xen parameter (iommu=superpage) to enable iommu super page.
Thanks,
We
Signed-off-by: Wei Wang <wei.wang2@amd.com>
--
Legal Information:
Advanced Micro Devices GmbH
Sitz: Dornach, Gemeinde Aschheim, 
Landkreis München Registergericht München, 
HRB Nr. 43632
Geschäftsführer:
Alberto Bozzo, Andrew Bowd

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diff -r 823658b538f2 xen/drivers/passthrough/iommu.c
--- a/xen/drivers/passthrough/iommu.c	Wed Nov 24 17:17:53 2010 +0100
+++ b/xen/drivers/passthrough/iommu.c	Wed Nov 24 17:19:13 2010 +0100
@@ -49,6 +49,7 @@ bool_t __read_mostly iommu_intremap = 1;
 bool_t __read_mostly iommu_intremap = 1;
 bool_t __read_mostly amd_iommu_debug;
 bool_t __read_mostly amd_iommu_perdev_intremap;
+bool_t __read_mostly iommu_super_page;
 
 static void __init parse_iommu_param(char *s)
 {
@@ -81,6 +82,8 @@ static void __init parse_iommu_param(cha
             iommu_passthrough = 1;
         else if ( !strcmp(s, "dom0-strict") )
             iommu_dom0_strict = 1;
+        else if ( !strcmp(s, "superpage") )
+            iommu_super_page = 1;
 
         s = ss + 1;
     } while ( ss );
diff -r 823658b538f2 xen/include/xen/iommu.h
--- a/xen/include/xen/iommu.h	Wed Nov 24 17:17:53 2010 +0100
+++ b/xen/include/xen/iommu.h	Wed Nov 24 17:19:13 2010 +0100
@@ -32,6 +32,7 @@ extern bool_t iommu_snoop, iommu_qinval,
 extern bool_t iommu_snoop, iommu_qinval, iommu_intremap;
 extern bool_t amd_iommu_debug;
 extern bool_t amd_iommu_perdev_intremap;
+extern bool_t iommu_super_page;
 
 extern struct rangeset *mmio_ro_ranges;
 

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Re: [PATCH 2/4] amd iommu: Large io page support - parameter

[Keir Fraser]

Why? If the system supports superpages, use them. Simple.

 -- Keir

On 03/12/2010 08:03, "Wei Wang2" <wei.wang2@amd.com> wrote:

> Add a xen parameter (iommu=superpage) to enable iommu super page.
> Thanks,
> We
> Signed-off-by: Wei Wang <wei.wang2@amd.com>
> --
> Legal Information:
> Advanced Micro Devices GmbH
> Sitz: Dornach, Gemeinde Aschheim,
> Landkreis München Registergericht München,
> HRB Nr. 43632
> Geschäftsführer:
> Alberto Bozzo, Andrew Bowd
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xensource.com
> http://lists.xensource.com/xen-devel

Re: [PATCH 2/4] amd iommu: Large io page support - parameter

[Wei Wang2]

Keir,
It could be used to disable super iommu page if the new codes have some 
issues. But I am OK with removing it if you think this parameter is 
unnecessary. 
Thanks,
Wei
 
On Friday 03 December 2010 17:14:12 Keir Fraser wrote:
> Why? If the system supports superpages, use them. Simple.
>
>  -- Keir
>
> On 03/12/2010 08:03, "Wei Wang2" <wei.wang2@amd.com> wrote:
> > Add a xen parameter (iommu=superpage) to enable iommu super page.
> > Thanks,
> > We
> > Signed-off-by: Wei Wang <wei.wang2@amd.com>
> > --
> > Legal Information:
> > Advanced Micro Devices GmbH
> > Sitz: Dornach, Gemeinde Aschheim,
> > Landkreis München Registergericht München,
> > HRB Nr. 43632
> > Geschäftsführer:
> > Alberto Bozzo, Andrew Bowd
> > _______________________________________________
> > Xen-devel mailing list
> > Xen-devel@lists.xensource.com
> > http://lists.xensource.com/xen-devel

Re: [PATCH 2/4] amd iommu: Large io page support - parameter

[Keir Fraser]

On 03/12/2010 08:19, "Wei Wang2" <wei.wang2@amd.com> wrote:

> Keir,
> It could be used to disable super iommu page if the new codes have some
> issues. But I am OK with removing it if you think this parameter is
> unnecessary. 

Yeah there's a judgement call there. But we don't add command-line flags for
every new feature we implement, and in this case I don't think it's
worthwhile. The iommu= set of parameters is hairy enough as it is. We can
always add the parameter *if* it proves to be worthwhile.

 -- Keir

> Thanks,
> Wei
>  
> On Friday 03 December 2010 17:14:12 Keir Fraser wrote:
>> Why? If the system supports superpages, use them. Simple.
>> 
>>  -- Keir
>> 
>> On 03/12/2010 08:03, "Wei Wang2" <wei.wang2@amd.com> wrote:
>>> Add a xen parameter (iommu=superpage) to enable iommu super page.
>>> Thanks,
>>> We
>>> Signed-off-by: Wei Wang <wei.wang2@amd.com>
>>> --
>>> Legal Information:
>>> Advanced Micro Devices GmbH
>>> Sitz: Dornach, Gemeinde Aschheim,
>>> Landkreis München Registergericht München,
>>> HRB Nr. 43632
>>> Geschäftsführer:
>>> Alberto Bozzo, Andrew Bowd
>>> _______________________________________________
>>> Xen-devel mailing list
>>> Xen-devel@lists.xensource.com
>>> http://lists.xensource.com/xen-devel
> 
> 
>