From: "Jan Beulich" <JBeulich@suse.com>
To: Ian Campbell <ian.campbell@citrix.com>
Cc: Ian.Campbell@eu.citrix.com, paolo.valente@unimore.it,
keir@xen.org, stefano.stabellini@eu.citrix.com,
andrew.cooper3@citrix.com, dario.faggioli@citrix.com,
Julien Grall <julien.grall@linaro.org>,
Ian.Jackson@eu.citrix.com, xen-devel@lists.xen.org,
julien.grall@citrix.com, etrudeau@broadcom.com, tim@xen.org,
Arianna Avanzini <avanzini.arianna@gmail.com>,
viktor.kleinik@globallogic.com
Subject: Re: [PATCH v8 13/14] tools/libxl: explicitly grant access to needed I/O-memory ranges
Date: Thu, 05 Jun 2014 15:53:55 +0100 [thread overview]
Message-ID: <5390A0A30200007800018502@mail.emea.novell.com> (raw)
In-Reply-To: <1401978693.15729.116.camel@hastur.hellion.org.uk>
>>> On 05.06.14 at 16:31, <ian.campbell@citrix.com> wrote:
> On Mon, 2014-05-26 at 12:15 +0100, Jan Beulich wrote:
>> >>> IHMO, the guest doesn't need to have permission to this region. When
>> >>> QEMU ask to map this region to the guest, the hypercall will only check
>> >>> the permission on the domain where QEMU is running. Therefore, the
>> >>> permission should be given to the stubdomain.
>> >>
>> >> How would qemu be involved in I/O from/to a passed through
>> >> device?
>> >
>> > AFAIU, the mapping of the range 0xa0000-* will be done by QEMU for an
>> > HVM guest (i.e calling xc_domain_memory_mapping).
>>
>> If qemu is mapping this _machine_ range to every guest (or every
>> guest getting a GFX device passed through) that would be wrong
>> then too afaict.
>
> How does this work today then? Do no guests get access to 0xa0000 or do
> we some how determine which of the multiple GFX devices is the primary
> one (with the real 0xa0000 mapped to it)?
I don't know. All that is clear is that the way it is being proposed here
(no matter whether that's a copy of current qemu behavior) can't be
right.
> I can't see 0xa0000 mapped by anything in xen.git and there are too many
> hits on the qemu tree for me to spot it if it is there.
Right - that's all I can tell too.
Jan
next prev parent reply other threads:[~2014-06-05 14:53 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-25 10:51 [PATCH v8 00/14] Implement the XEN_DOMCTL_memory_mapping hypercall for ARM Arianna Avanzini
2014-05-25 10:51 ` [PATCH v8 01/14] arch/arm: domain build: let dom0 access I/O memory of mapped devices Arianna Avanzini
2014-06-10 15:04 ` Ian Campbell
2014-05-25 10:51 ` [PATCH v8 02/14] arch/arm: add consistency check to REMOVE p2m changes Arianna Avanzini
2014-05-25 15:50 ` Julien Grall
2014-06-05 13:45 ` Ian Campbell
2014-06-05 13:50 ` Ian Campbell
2014-05-25 10:51 ` [PATCH v8 03/14] arch/arm: let map_mmio_regions() take pfn as parameters Arianna Avanzini
2014-05-25 10:51 ` [PATCH v8 04/14] arch/arm: let map_mmio_regions() use start and count Arianna Avanzini
2014-05-25 15:56 ` Julien Grall
2014-06-05 13:53 ` Ian Campbell
2014-05-25 10:51 ` [PATCH v8 05/14] arch/arm: unmap partially-mapped I/O-memory regions Arianna Avanzini
2014-05-25 16:04 ` Julien Grall
2014-06-05 14:03 ` Ian Campbell
2014-06-05 14:09 ` Julien Grall
2014-05-25 10:51 ` [PATCH v8 06/14] arch/x86: warn if to-be-removed mapping does not exist Arianna Avanzini
2014-06-05 14:06 ` Ian Campbell
2014-05-25 10:51 ` [PATCH v8 07/14] arch/x86: cleanup memory_mapping DOMCTL Arianna Avanzini
2014-05-26 9:57 ` Jan Beulich
2014-05-25 10:51 ` [PATCH v8 08/14] xen/common: move memory_type_changed() function to common code Arianna Avanzini
2014-05-25 16:15 ` Julien Grall
2014-05-26 9:58 ` Jan Beulich
2014-06-05 14:08 ` Ian Campbell
2014-05-25 10:51 ` [PATCH v8 09/14] xen/x86: factor out map and unmap from the memory_mapping DOMCTL Arianna Avanzini
2014-05-26 10:04 ` Jan Beulich
2014-05-25 10:51 ` [PATCH v8 10/14] xen/common: move the memory_mapping DOMCTL hypercall to common code Arianna Avanzini
2014-05-25 16:42 ` Julien Grall
2014-05-26 10:07 ` Jan Beulich
2014-05-26 11:03 ` Julien Grall
2014-06-05 14:21 ` Ian Campbell
2014-06-05 14:33 ` Tim Deegan
2014-06-05 14:39 ` Ian Campbell
2014-05-26 10:06 ` Jan Beulich
2014-05-25 10:51 ` [PATCH v8 11/14] tools/libxl: parse optional start gfn from the iomem config option Arianna Avanzini
2014-05-25 10:51 ` [PATCH v8 12/14] tools/libxl: handle the iomem parameter with the memory_mapping hcall Arianna Avanzini
2014-05-25 17:04 ` Julien Grall
2014-06-05 14:27 ` Ian Campbell
2014-05-25 10:51 ` [PATCH v8 13/14] tools/libxl: explicitly grant access to needed I/O-memory ranges Arianna Avanzini
2014-05-25 17:08 ` Julien Grall
2014-05-26 10:11 ` Jan Beulich
2014-05-26 10:58 ` Julien Grall
2014-05-26 11:15 ` Jan Beulich
2014-06-05 14:31 ` Ian Campbell
2014-06-05 14:37 ` Ian Campbell
2014-06-05 14:54 ` Jan Beulich
2014-06-05 14:53 ` Jan Beulich [this message]
2014-05-26 10:10 ` Jan Beulich
2014-05-25 10:51 ` [PATCH v8 14/14] xen/common: do not implicitly permit access to mapped I/O memory Arianna Avanzini
2014-07-01 10:45 ` [PATCH v8 00/14] Implement the XEN_DOMCTL_memory_mapping hypercall for ARM Julien Grall
2014-07-01 10:55 ` Arianna Avanzini
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