From: Avi Kivity <avi@redhat.com>
To: Dirk Gouders <gouders@et.bocholt.fh-gelsenkirchen.de>
Cc: kvm@vger.kernel.org, Chris Wright <chrisw@redhat.com>
Subject: Re: Prevent IRQ sharing for PCI passthrough
Date: Fri, 14 May 2010 20:14:24 +0300 [thread overview]
Message-ID: <4BED84F0.8050600@redhat.com> (raw)
In-Reply-To: <gi39xuu8n5.fsf@mx10.gouders.net>
On 05/14/2010 12:37 PM, Dirk Gouders wrote:
>
>>> Even after extensive searching/reading, I am not sure if it possible to
>>> prevent a PCI card from sharing an interrupt with other devices or
>>> probably manually assign a free interrupt to that card via some kernel
>>> parameter and would be glad if someone could give me an answer to that
>>> question.
>>>
>>>
>> There is an ACPI _SRS method which can be used to move interrupts
>> around. However Linux doesn't appear to expose it. Even if it did,
>> the interrupt may be shared on the motherboard, in which case nothing
>> would help (though you might be able to share it with unused devices).
>>
> You mean by providing a custom DSDT, right?
> A quick look in drivers/acpi/pci_link.c shows a TBD comment mentioning
> _SRS but I will have to have a deeper look at this subject, because its
> quite new to me.
>
>
No, there should be an _SRS method in your existing DSDT. But Linux
doesn't call it (except after resume etc.) and doesn't allow the user to
use _SRS to move interrupts around.
--
Do not meddle in the internals of kernels, for they are subtle and quick to panic.
prev parent reply other threads:[~2010-05-14 17:14 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-05-13 16:57 Prevent IRQ sharing for PCI passthrough Dirk Gouders
2010-05-13 17:21 ` Avi Kivity
2010-05-13 17:26 ` Chris Wright
2010-05-14 9:49 ` Dirk Gouders
2010-05-14 9:37 ` Dirk Gouders
2010-05-14 17:14 ` Avi Kivity [this message]
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