Re: [PATCH] VT-d: improve RMRR validity checking

[Weidong Han <weidong.han@intel.com>]

Alex Williamson wrote:
> On Thu, 2010-03-11 at 11:44 +0800, Weidong Han wrote:   
>   
>> good suggestion to check the device type. I cooked a new patch. It skips 
>> checking IOAPIC and HPET. pls have a try.
>>     
>
> I like this approach better, but the patch doesn't work as is.  The
> problem is acpi_scope is getting incremented as a structure instead of
> by length bytes.  It either needs to be cast on the increment, or maybe
> cast on use like this:
>
> Signed-off-by: Alex Williamson <alex.williamson@hp.com>
>
> diff -r 132ac04cbdba xen/drivers/passthrough/vtd/dmar.c
> --- a/xen/drivers/passthrough/vtd/dmar.c	Tue Mar 09 18:18:19 2010 +0000
> +++ b/xen/drivers/passthrough/vtd/dmar.c	Wed Mar 10 21:46:49 2010 -0700
> @@ -407,9 +407,15 @@
>      {
>          u8 b, d, f;
>          int i, invalid_cnt = 0;
> +        void *p;
>  
> -        for ( i = 0; i < dmaru->scope.devices_cnt; i++ )
> +        for ( i = 0, p = dev_scope_start; i < dmaru->scope.devices_cnt;
> +              i++, p += ((struct acpi_dev_scope *)p)->length )
>          {
> +            if ( ((struct acpi_dev_scope *)p)->dev_type == ACPI_DEV_IOAPIC ||
> +                 ((struct acpi_dev_scope *)p)->dev_type == ACPI_DEV_MSI_HPET )
> +                continue;
> +
>              b = PCI_BUS(dmaru->scope.devices[i]);
>              d = PCI_SLOT(dmaru->scope.devices[i]);
>              f = PCI_FUNC(dmaru->scope.devices[i]);
>   

Acked-by: Weidong Han <weidong.han@intel.com>

Regards,
Weidong
>
>   
>> diff -r cadf1bae9ee2 xen/drivers/passthrough/vtd/dmar.c
>> --- a/xen/drivers/passthrough/vtd/dmar.c    Thu Feb 25 18:26:45 2010 +0800
>> +++ b/xen/drivers/passthrough/vtd/dmar.c    Thu Mar 11 19:39:45 2010 +0800
>> @@ -407,9 +407,15 @@ acpi_parse_one_drhd(struct acpi_dmar_ent
>>      {
>>          u8 b, d, f;
>>          int i, invalid_cnt = 0;
>> +        struct acpi_dev_scope *acpi_scope = dev_scope_start;
>>
>>          for ( i = 0; i < dmaru->scope.devices_cnt; i++ )
>>          {
>> +            acpi_scope += (i == 0) ? 0 : acpi_scope->length;
>> +            if ( acpi_scope->dev_type == ACPI_DEV_IOAPIC ||
>> +                 acpi_scope->dev_type == ACPI_DEV_MSI_HPET )
>> +                continue;
>> +
>>              b = PCI_BUS(dmaru->scope.devices[i]);
>>              d = PCI_SLOT(dmaru->scope.devices[i]);
>>              f = PCI_FUNC(dmaru->scope.devices[i]);
>>
>>
>>     
>
>
>