From: Mark Rutland <mark.rutland@arm.com>
To: Jan Beulich <JBeulich@suse.com>
Cc: "linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
"matt.fleming@intel.com" <matt.fleming@intel.com>,
"Ian.Campbell@citrix.com" <Ian.Campbell@citrix.com>,
Stefano Stabellini <stefano.stabellini@eu.citrix.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"daniel.kiper@oracle.com" <daniel.kiper@oracle.com>,
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"peter.huangpeng@huawei.com" <peter.huangpeng@huawei.com>,
"leif.lindholm@linaro.org" <leif.lindholm@linaro.org>,
"xen-devel@lists.xen.org" <xen-devel@lists.xen.org>,
"julien.grall@citrix.com" <julien.grall@citrix.com>,
"freebsd-arm@freebsd.org" <freebsd-arm@freebsd.org>,
"linux-efi@vger.kernel.org" <linux-efi@vger.kernel.org>,
shannon.zhao@linaro.or
Subject: Re: [PATCH] efi/libstub/fdt: Standardize the names of EFI stub parameters
Date: Fri, 11 Sep 2015 17:36:05 +0100 [thread overview]
Message-ID: <20150911163605.GC8726__29879.3188216679$1441989456$gmane$org@leverpostej> (raw)
In-Reply-To: <55F1B89802000078000A1C9B@prv-mh.provo.novell.com>
> >> Considering that the EFI support is just for Dom0, and Dom0 (at
> >> the time) had to be PV anyway, it was the more natural solution to
> >> expose the interface via hypercalls, the more that this allows better
> >> control over what is and primarily what is not being exposed to
> >> Dom0. With the wrapper approach we'd be back to the same
> >> problem (discussed elsewhere) of which EFI version to surface: The
> >> host one would impose potentially missing extensions, while the
> >> most recent hypervisor known one might imply hiding valuable
> >> information from Dom0. Plus there are incompatible changes like
> >> the altered meaning of EFI_MEMORY_WP in 2.5.
> >
> > I'm not sure I follow how hypercalls solve any impedance mismatch here;
> > you're still expecting Dom0 to call up to Xen in order to perform calls,
> > and all I suggested was a different location for those hypercalls.
> >
> > If Xen is happy to make such calls blindly, why does it matter if the
> > hypercall was in the kernel binary or an external shim?
>
> Because there could be new entries in SystemTable->RuntimeServices
> (expected and blindly but validly called by the kernel). Even worse
> (because likely harder to deal with) would be new fields in other
> structures.
Any of these could cause Xen to blow up, while Xen could always provide
a known-safe (but potentially sub-optimal) view to the kernel by
default.
> > Incompatible changes are a spec problem regardless of how this is
> > handled.
>
> Not necessarily - we don't expose the memory map (we'd have to
> if we were to mimic EFI for Dom0), and hence the mentioned issue
> doesn't exist in our model.
We have to expose _some_ memory map, so I don't follow this point.
Mark.
next prev parent reply other threads:[~2015-09-11 16:36 UTC|newest]
Thread overview: 182+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-10 8:41 [PATCH] efi/libstub/fdt: Standardize the names of EFI stub parameters Shannon Zhao
2015-09-10 8:41 ` Shannon Zhao
2015-09-10 8:41 ` Shannon Zhao
2015-09-10 9:52 ` Mark Rutland
2015-09-10 9:52 ` Mark Rutland
2015-09-10 9:52 ` Mark Rutland
2015-09-10 10:19 ` Stefano Stabellini
2015-09-10 10:19 ` Stefano Stabellini
2015-09-10 10:19 ` Stefano Stabellini
2015-09-10 11:24 ` Mark Rutland
2015-09-10 11:24 ` Mark Rutland
2015-09-10 11:24 ` Mark Rutland
2015-09-10 11:37 ` Stefano Stabellini
2015-09-10 11:37 ` Stefano Stabellini
2015-09-10 11:37 ` Stefano Stabellini
2015-09-10 11:37 ` Stefano Stabellini
2015-09-10 12:15 ` Mark Rutland
2015-09-10 12:15 ` Mark Rutland
2015-09-10 12:15 ` Mark Rutland
2015-09-10 12:15 ` Mark Rutland
2015-09-10 12:58 ` Ian Campbell
2015-09-10 12:58 ` [Xen-devel] " Ian Campbell
2015-09-10 12:58 ` Ian Campbell
2015-09-10 12:58 ` Ian Campbell
2015-09-10 13:08 ` Jan Beulich
2015-09-10 13:08 ` Jan Beulich
2015-09-10 13:08 ` Jan Beulich
2015-09-10 13:30 ` Ian Campbell
2015-09-10 13:30 ` [Xen-devel] " Ian Campbell
2015-09-10 13:30 ` Ian Campbell
2015-09-10 13:30 ` Ian Campbell
2015-09-10 13:08 ` Jan Beulich
2015-09-10 13:52 ` Stefano Stabellini
2015-09-10 13:52 ` Stefano Stabellini
2015-09-10 13:52 ` Stefano Stabellini
2015-09-10 13:52 ` Stefano Stabellini
2015-09-10 14:13 ` Leif Lindholm
2015-09-10 14:13 ` Leif Lindholm
2015-09-10 14:13 ` Leif Lindholm
2015-09-10 14:13 ` Leif Lindholm
2015-09-10 14:49 ` Mark Rutland
2015-09-10 14:49 ` Mark Rutland
2015-09-10 14:49 ` Mark Rutland
2015-09-10 16:10 ` Stefano Stabellini
2015-09-10 16:10 ` Stefano Stabellini
2015-09-10 16:10 ` Stefano Stabellini
2015-09-10 16:10 ` Stefano Stabellini
2015-09-10 16:23 ` Mark Rutland
2015-09-10 16:23 ` Mark Rutland
2015-09-10 16:23 ` Mark Rutland
2015-09-10 16:23 ` Mark Rutland
2015-09-11 12:46 ` Daniel Kiper
2015-09-11 12:46 ` Daniel Kiper
2015-09-11 12:46 ` Daniel Kiper
2015-09-11 12:46 ` Daniel Kiper
2015-09-11 13:14 ` Stefano Stabellini
2015-09-11 13:14 ` Stefano Stabellini
2015-09-11 13:14 ` Stefano Stabellini
2015-09-11 13:30 ` Ard Biesheuvel
2015-09-11 13:30 ` Ard Biesheuvel
2015-09-11 13:30 ` Ard Biesheuvel
2015-09-11 13:30 ` Ard Biesheuvel
2015-09-11 15:45 ` Daniel Kiper
2015-09-11 15:45 ` Daniel Kiper
2015-09-11 15:45 ` Daniel Kiper
2015-09-14 8:42 ` Shannon Zhao
2015-09-14 8:42 ` Shannon Zhao
2015-09-14 8:42 ` Shannon Zhao
2015-09-14 9:09 ` Ard Biesheuvel
2015-09-14 9:09 ` Ard Biesheuvel
2015-09-14 9:09 ` Ard Biesheuvel
2015-09-14 9:09 ` Ard Biesheuvel
2015-09-14 9:31 ` Shannon Zhao
2015-09-14 9:31 ` Shannon Zhao
2015-09-14 9:31 ` Shannon Zhao
2015-09-14 9:36 ` Ard Biesheuvel
2015-09-14 9:36 ` Ard Biesheuvel
2015-09-14 9:36 ` Ard Biesheuvel
2015-09-14 9:36 ` Ard Biesheuvel
2015-09-14 10:39 ` Jan Beulich
2015-09-14 10:39 ` [Xen-devel] " Jan Beulich
2015-09-14 10:39 ` Jan Beulich
2015-09-14 10:39 ` Jan Beulich
2015-09-14 11:16 ` Ard Biesheuvel
2015-09-14 11:16 ` [Xen-devel] " Ard Biesheuvel
2015-09-14 11:16 ` Ard Biesheuvel
2015-09-14 11:16 ` Ard Biesheuvel
2015-09-14 11:34 ` Jan Beulich
2015-09-14 11:34 ` [Xen-devel] " Jan Beulich
2015-09-14 11:34 ` Jan Beulich
2015-09-14 11:34 ` Jan Beulich
2015-09-11 15:45 ` Daniel Kiper
2015-09-11 16:33 ` Mark Rutland
2015-09-11 16:33 ` Mark Rutland
2015-09-11 16:33 ` Mark Rutland
2015-09-11 16:33 ` Mark Rutland
2015-09-11 13:14 ` Stefano Stabellini
2015-09-11 16:25 ` Mark Rutland
2015-09-11 16:25 ` Mark Rutland
2015-09-11 16:25 ` Mark Rutland
2015-09-11 16:25 ` Mark Rutland
2015-09-12 11:36 ` Daniel Kiper
2015-09-12 11:36 ` Daniel Kiper
2015-09-12 11:36 ` Daniel Kiper
2015-09-12 11:36 ` Daniel Kiper
2015-09-14 9:25 ` Mark Rutland
2015-09-14 9:25 ` Mark Rutland
2015-09-14 9:25 ` Mark Rutland
2015-09-14 9:25 ` Mark Rutland
2015-09-14 9:43 ` Ard Biesheuvel
2015-09-14 9:43 ` Ard Biesheuvel
[not found] ` <CAKv+Gu9ER1cKvPHobq-wo7ggPesJj4OQ7=aTr24GVpubHvVqjQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-09-14 9:57 ` Ian Campbell
2015-09-14 9:57 ` Ian Campbell
2015-09-14 10:02 ` Ard Biesheuvel
[not found] ` <1442224673.3549.131.camel-Sxgqhf6Nn4DQT0dZR+AlfA@public.gmane.org>
2015-09-14 10:02 ` Ard Biesheuvel
2015-09-14 10:02 ` Ard Biesheuvel
2015-09-14 10:25 ` Ian Campbell
[not found] ` <CAKv+Gu_Gh649EwdtodLY9Q28JhqYg8o6RShXXH1ZbxsfYRfi2Q-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-09-14 10:25 ` Ian Campbell
2015-09-14 10:25 ` Ian Campbell
2015-09-14 12:28 ` Daniel Kiper
2015-09-14 12:28 ` Daniel Kiper
[not found] ` <20150914122858.GI4530-fJNZiO034lp9pOct4yEdx/3oZC3j2Omk@public.gmane.org>
2015-09-14 13:09 ` Ard Biesheuvel
2015-09-14 13:09 ` Ard Biesheuvel
[not found] ` <CAKv+Gu_z2X=9-qgoKTS7dKLqtSUvysyu9LzZryJqcSR4X8Ss6A-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-09-14 13:57 ` Daniel Kiper
2015-09-14 13:57 ` Daniel Kiper
2015-09-14 13:57 ` Daniel Kiper
2015-09-14 13:09 ` Ard Biesheuvel
2015-09-14 9:57 ` Ian Campbell
2015-09-14 12:28 ` Daniel Kiper
2015-09-14 9:43 ` Ard Biesheuvel
2015-09-14 9:47 ` Stefano Stabellini
2015-09-14 9:47 ` Stefano Stabellini
2015-09-14 9:47 ` Stefano Stabellini
2015-09-14 9:47 ` Stefano Stabellini
2015-09-14 12:19 ` Daniel Kiper
2015-09-14 12:19 ` Daniel Kiper
2015-09-14 12:19 ` Daniel Kiper
2015-09-14 12:19 ` Daniel Kiper
2015-09-11 11:00 ` Ian Campbell
2015-09-11 11:00 ` Ian Campbell
2015-09-11 11:00 ` Ian Campbell
2015-09-11 11:00 ` Ian Campbell
2015-09-10 14:49 ` Mark Rutland
2015-09-10 12:55 ` Jan Beulich
2015-09-10 12:55 ` Jan Beulich
2015-09-10 12:55 ` Jan Beulich
2015-09-10 12:55 ` Jan Beulich
2015-09-10 14:53 ` Mark Rutland
2015-09-10 14:53 ` Mark Rutland
2015-09-10 14:53 ` Mark Rutland
2015-09-10 15:06 ` Jan Beulich
2015-09-10 15:06 ` Jan Beulich
2015-09-10 15:06 ` Jan Beulich
2015-09-11 16:36 ` Mark Rutland [this message]
2015-09-11 16:36 ` Mark Rutland
2015-09-11 16:36 ` Mark Rutland
2015-09-11 16:36 ` Mark Rutland
2015-09-10 15:06 ` Jan Beulich
2015-09-10 11:24 ` Mark Rutland
2015-09-10 10:19 ` Stefano Stabellini
2015-09-10 9:52 ` Mark Rutland
2015-09-10 11:32 ` Andrew Turner
2015-09-10 11:32 ` Andrew Turner
2015-09-10 11:32 ` Andrew Turner
2015-09-10 11:48 ` Julien Grall
2015-09-10 11:48 ` Julien Grall
2015-09-10 11:48 ` Julien Grall
2015-09-10 12:05 ` Roger Pau Monné
2015-09-10 12:05 ` Roger Pau Monné
2015-09-10 12:05 ` Roger Pau Monné
2015-09-10 12:05 ` Roger Pau Monné
2015-09-10 12:53 ` [Xen-devel] " Julien Grall
2015-09-10 12:53 ` Julien Grall
2015-09-10 12:53 ` Julien Grall
2015-09-10 12:53 ` Julien Grall
2015-09-10 11:48 ` Julien Grall
2015-09-10 11:32 ` Andrew Turner
2015-09-17 11:43 ` Shannon Zhao
2015-09-17 11:43 ` Shannon Zhao
2015-09-17 11:43 ` Shannon Zhao
2015-09-17 11:43 ` Shannon Zhao
-- strict thread matches above, loose matches on Subject: below --
2015-09-10 8:41 Shannon Zhao
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