From: Peter Maydell <peter.maydell@linaro.org>
To: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Anthony PERARD <anthony.perard@citrix.com>,
"xen-devel@lists.xensource.com Devel"
<xen-devel@lists.xensource.com>,
QEMU Developers <qemu-devel@nongnu.org>
Subject: Re: [Qemu-devel] [PATCH 2/2] xen: build on ARM
Date: Tue, 17 Dec 2013 18:27:37 +0000 [thread overview]
Message-ID: <CAFEAcA9==C4b0hmsnAZUzAgPRm_ecvQOdesYa=n-mfbYECP6AA@mail.gmail.com> (raw)
In-Reply-To: <alpine.DEB.2.02.1312171818320.8667@kaball.uk.xensource.com>
On 17 December 2013 18:20, Stefano Stabellini
<stefano.stabellini@eu.citrix.com> wrote:
> On Tue, 17 Dec 2013, Peter Maydell wrote:
>> Per-host-architecture ifdef ladders are kind of nasty. What's this
>> code actually trying to do ? (looks like maybe "64 bit host addresses
>> vs 32 bit host addresses" ?)
>
> Almost.
> It is trying to decide how much stuff we can map into QEMU's address
> space (that is what the "Cap" is referring to). In particular consider
> the case where we are running on an ARMv8 system, dom0 and QEMU are
> 32-bit and the guest is 64-bit.
Right, so you essentially want to know the size of a host address
(that's 32 bits in a 32 bit QEMU even if the h/w is ARMv8).
#if HOST_LONG_BITS == 32
[stuff for 32 bit address space]
#else
[stuff for 64 bit address space]
#endif
thanks
-- PMM
next prev parent reply other threads:[~2013-12-17 18:28 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-12-17 17:30 [Qemu-devel] [PATCH 0/2] build QEMU with Xen support on ARM Stefano Stabellini
2013-12-17 17:30 ` [Qemu-devel] [PATCH 1/2] xen_backend: introduce xenstore_read_uint64 and xenstore_read_fe_uint64 Stefano Stabellini
2013-12-17 17:56 ` Peter Maydell
2013-12-17 18:28 ` Stefano Stabellini
2013-12-17 17:31 ` [Qemu-devel] [PATCH 2/2] xen: build on ARM Stefano Stabellini
2013-12-17 17:58 ` Peter Maydell
2013-12-17 18:20 ` Stefano Stabellini
2013-12-17 18:27 ` Peter Maydell [this message]
2013-12-18 11:25 ` [Qemu-devel] [Xen-devel] " Ian Campbell
2013-12-18 12:35 ` Stefano Stabellini
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