[Xen-devel] [VTD][PATCH] interrupt remapping (2nd try)

["Kay, Allen M" <allen.m.kay@xxxxxxxxx>]

This second iteration of the patch does what was describe below: calls
io_apic_read_remap_rte/io_apic_write_remap_rte in
io_apic_read/io_apic_write if vtd=1.

Gsi_remapping call has been removed.

Signed-off-by: Allen Kay <allen.m.kay@xxxxxxxxx>

>-----Original Message-----
>From: Kay, Allen M 
>Sent: Saturday, January 26, 2008 12:10 AM
>To: 'Keir Fraser'; xen-devel@xxxxxxxxxxxxxxxxxxx
>Cc: Han, Weidong
>Subject: RE: [Xen-devel] [VTD][PATCH] interrupt remapping 
>patch for xen 3.3
>
>Actually I have a patch that modifies low level macros 
>io_apic_read()/io_apic_write() to call 
>io_apic_read_remap_rte/io_apic_write_remap_rte() if vt-d is enabled.
>
>Since dom0 accesses io-apic hardware via these two macros, 
>this should not cause conflicts.  With these low level macros 
>modified, the call to gsi_remapping() will no longer be needed.
>
>Let me know what you think about it.  I can send you a refreshed patch.
>
>Allen
>
>>-----Original Message-----
>>From: Keir Fraser [mailto:Keir.Fraser@xxxxxxxxxxxx] 
>>Sent: Thursday, January 24, 2008 11:39 PM
>>To: Kay, Allen M; xen-devel@xxxxxxxxxxxxxxxxxxx
>>Cc: Han, Weidong
>>Subject: Re: [Xen-devel] [VTD][PATCH] interrupt remapping 
>>patch for xen 3.3
>>
>>Okay, that only made a little sense to me. The main problem I 
>have with
>>fiddling with io-apic entries is that they're all actually under the
>>management of dom0 kernel.
>>
>> -- Keir
>>
>>On 24/1/08 22:33, "Kay, Allen M" <allen.m.kay@xxxxxxxxx> wrote:
>>
>>> Interrupt remapping redirects ioapic/msi interrupt entries 
>>to interrupt
>>> remap table.  SID field in the Interrupt Remapping Table 
>>Entry qualifies
>>> the interrupt with BDF information of the ioapic/MSI devices.
>>> 
>>> Therefore the main value it adds for current Xen VT-d/PCI 
>passthru is
>>> that it protects hypervisor interrupts from malicious attacks from
>>> guests with passthru devices.  Other benefits it can provide 
>>is easier
>>> IRQ rebalancing and extended APIC ID support.
>>> 
>>> Allen
>>> 
>>>> -----Original Message-----
>>>> From: Keir Fraser [mailto:Keir.Fraser@xxxxxxxxxxxx]
>>>> Sent: Thursday, January 24, 2008 12:14 AM
>>>> To: Kay, Allen M; xen-devel@xxxxxxxxxxxxxxxxxxx
>>>> Cc: Han, Weidong
>>>> Subject: Re: [Xen-devel] [VTD][PATCH] interrupt remapping
>>>> patch for xen 3.3
>>>> 
>>>> What exactly does irq remapping mean, and what are its 
>>benefits in the
>>>> current Xen VT-D architecture? It's really not at all clear
>>>> what's going on
>>>> from the current VT-D documentation.
>>>> 
>>>> Since all interrupts get abstracted through Xen right now, if
>>>> it's just an
>>>> interrupt-line remapping then that doesn't seem very useful...
>>>> 
>>>> -- Keir
>>>> 
>>>> On 24/1/08 02:33, "Kay, Allen M" <allen.m.kay@xxxxxxxxx> wrote:
>>>> 
>>>>> Attached patch remaps interrupt for passthru device if such HW is
>>>>> detected on VT-d platforms.
>>>>> 
>>>>> Signed-off-by: Allen Kay <allen.m.kay@xxxxxxxxx>
>>>>> _______________________________________________
>>>>> Xen-devel mailing list
>>>>> Xen-devel@xxxxxxxxxxxxxxxxxxx
>>>>> http://lists.xensource.com/xen-devel
>>>> 
>>>> 
>>>> 
>>
>>
>>
>

Attachment: intremap_0130.patch
Description: intremap_0130.patch

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