From: Jan Kiszka <jan.kiszka@siemens.com>
To: Mark Rutland <mark.rutland@arm.com>
Cc: devicetree <devicetree@vger.kernel.org>,
"Pantelis Antoniou" <pantelis.antoniou@konsulko.com>,
"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>,
Jailhouse <jailhouse-dev@googlegroups.com>,
"Måns Rullgård" <mans@denx.de>,
"Antonios Motakis" <antonios.motakis@huawei.com>
Subject: Re: Using DT overlays for adding virtual hardware
Date: Wed, 8 Jun 2016 17:27:26 +0200 [thread overview]
Message-ID: <5758395E.4000508@siemens.com> (raw)
In-Reply-To: <20160608151745.GB13355@leverpostej>
On 2016-06-08 17:17, Mark Rutland wrote:
> On Wed, Jun 08, 2016 at 04:16:32PM +0200, Jan Kiszka wrote:
>> Hi all,
>>
>> already started the discussion off-list with Pantelis, but it's better
>> done in public:
>>
>> I'm currently exploring ways to make Linux recognize dynamically added
>> virtual hardware when running under the Jailhouse hypervisor [1]. We
>> need to load drivers for inter-partition communication devices that only
>> appear after Jailhouse started (which is done from within Linux, i.e.
>> long after boot) or when a partition was added later on. Probably, we
>> will simply add a virtual PCI host bridge on systems without physical
>> PCI and let the IPC device be explored that way (already works on x86).
>> Still, that leaves us with hotplug and unplug on hypervisor activation
>> and deactivation.
>
> If I've understood correctly you want to use overlays to inject the
> virtual PCI host bridge?
>
> Given that you know precisely what you want to inject, I'm not sure I
> see the value of using an overlay.
>
> Is there some reason you can't just create a device without having to go
> via an intermediate step? As I understand it, Xen does that for (some)
> virtual devices provided to Dom0 and DomU.
I don't want to write yet another virtual driver but ideally reuse
pci-host-generic. Possibly a dumb question, but bow can I make Linux
instantiate a device node compatible with that driver and with the
desired resources? That's what made me think of overlays.
Thanks,
Jan
--
Siemens AG, Corporate Technology, CT RDA ITP SES-DE
Corporate Competence Center Embedded Linux
next prev parent reply other threads:[~2016-06-08 15:27 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-08 14:16 Using DT overlays for adding virtual hardware Jan Kiszka
2016-06-08 15:17 ` Mark Rutland
2016-06-08 15:27 ` Jan Kiszka [this message]
2016-06-08 15:57 ` Pantelis Antoniou
2016-06-08 16:23 ` Mark Rutland
2016-06-08 16:31 ` Pantelis Antoniou
2016-06-08 16:39 ` Jan Kiszka
2016-06-09 6:03 ` Jan Kiszka
2016-06-21 10:13 ` Jan Kiszka
2016-06-21 10:24 ` Pantelis Antoniou
2016-06-21 11:22 ` Jan Kiszka
2016-06-21 11:35 ` Pantelis Antoniou
2016-06-21 11:43 ` Jan Kiszka
2016-06-21 11:45 ` Pantelis Antoniou
2016-06-21 11:59 ` Jan Kiszka
2016-06-21 13:12 ` Jan Kiszka
2016-06-21 13:29 ` Pantelis Antoniou
2016-06-09 7:22 ` Arnd Bergmann
2016-06-10 14:57 ` Jan Kiszka
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