From: Julien Grall <julien.grall@citrix.com>
To: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>,
Manish Jaggi <mjaggi@caviumnetworks.com>,
Prasun Kapoor <Prasun.kapoor@caviumnetworks.com>,
"Kumar, Vijaya" <Vijaya.Kumar@caviumnetworks.com>,
"xen-devel@lists.xen.org" <xen-devel@lists.xen.org>,
Stefano Stabellini <stefano.stabellini@citrix.com>,
"Kulkarni, Ganapatrao" <Ganapatrao.Kulkarni@caviumnetworks.com>
Subject: Re: PCI Pass-through in Xen ARM - Draft 2.
Date: Tue, 14 Jul 2015 18:58:29 +0200 [thread overview]
Message-ID: <55A53FB5.20906@citrix.com> (raw)
In-Reply-To: <alpine.DEB.2.02.1507141742150.17378@kaball.uk.xensource.com>
Hi Stefano,
On 14/07/2015 18:46, Stefano Stabellini wrote:
>>> Linux provides a function (pci_for_each_dma_alias) which will return a
>>> requester ID for a given PCI device. It appears that the BDF (the 's' of sBDF
>>> is only internal to Linux and not part of the hardware) is equal to the
>>> requester ID on your platform but we can't assume it for anyone else.
>>
>> The PCI Express Base Specification states that the requester ID is "The
>> combination of a Requester's Bus Number, Device Number, and Function
>> Number that uniquely identifies the Requester."
>>
>> I think it is safe to assume BDF = requester ID on all platforms.
>
> With the catch that in case of ARI devices
> (http://pcisig.com/sites/default/files/specification_documents/ECN-alt-rid-interpretation-070604.pdf),
> BDF is actually BF because the device number is always 0 and the
> function number is 8 bits.
And some other problem such as broken PCI device...
Both Xen x86 (domain_context_mapping in drivers/passthrough/vtd/iommu.c)
and Linux (pci_dma_for_each_alias) use a code more complex than
requesterID = BDF.
So I don't think we can use requesterID = BDF in physdev op unless we
are *stricly* sure this is valid.
Although, based on the x86 code, Xen should be able to translate the BDF
into the requester ID...
Regards,
--
Julien Grall
next prev parent reply other threads:[~2015-07-14 16:58 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-28 18:38 PCI Pass-through in Xen ARM - Draft 2 Manish Jaggi
2015-06-29 10:31 ` Julien Grall
2015-06-29 10:50 ` Ian Campbell
2015-06-29 11:00 ` Julien Grall
2015-07-05 5:55 ` Manish Jaggi
2015-07-06 6:13 ` Manish Jaggi
2015-07-06 9:11 ` Ian Campbell
2015-07-06 10:06 ` Manish Jaggi
2015-07-06 10:20 ` Ian Campbell
2015-07-29 9:37 ` Manish Jaggi
2015-07-30 9:54 ` Ian Campbell
2015-07-30 12:51 ` Manish Jaggi
2015-07-30 14:39 ` Ian Campbell
2015-07-31 7:46 ` Manish Jaggi
2015-07-31 8:05 ` Ian Campbell
2015-07-31 10:32 ` Ian Campbell
2015-07-31 14:24 ` Konrad Rzeszutek Wilk
2015-07-31 11:07 ` Manish Jaggi
2015-07-31 11:19 ` Ian Campbell
2015-07-31 12:50 ` Manish Jaggi
2015-07-31 12:57 ` Ian Campbell
2015-07-31 12:59 ` Julien Grall
2015-07-31 13:27 ` Ian Campbell
2015-07-31 14:33 ` Manish Jaggi
2015-07-31 14:56 ` Julien Grall
2015-07-31 15:12 ` Manish Jaggi
2015-07-31 15:13 ` Julien Grall
2015-07-06 10:43 ` Julien Grall
2015-07-06 11:09 ` Manish Jaggi
2015-07-06 11:45 ` Julien Grall
2015-07-07 7:10 ` Manish Jaggi
2015-07-07 8:18 ` Julien Grall
2015-07-07 8:46 ` Manish Jaggi
2015-07-07 10:54 ` Manish Jaggi
2015-07-07 11:24 ` Ian Campbell
2015-07-09 7:13 ` Manish Jaggi
2015-07-09 8:08 ` Julien Grall
2015-07-09 10:30 ` Manish Jaggi
2015-07-09 13:57 ` Julien Grall
2015-07-10 6:07 ` Pranavkumar Sawargaonkar
2015-07-14 16:37 ` Stefano Stabellini
2015-07-14 16:46 ` Stefano Stabellini
2015-07-14 16:58 ` Julien Grall [this message]
2015-07-14 18:01 ` Stefano Stabellini
2015-07-22 5:41 ` Manish Jaggi
2015-07-22 8:34 ` Julien Grall
2015-07-14 16:47 ` Stefano Stabellini
2015-07-07 15:27 ` Konrad Rzeszutek Wilk
2015-06-29 15:34 ` Ian Campbell
2015-07-05 6:07 Manish Jaggi
2015-07-06 9:07 ` Ian Campbell
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