From: Keir Fraser <keir.fraser@eu.citrix.com>
To: Dan Magenheimer <dan.magenheimer@oracle.com>,
"Xen-Devel (xen-devel@lists.xensource.com)"
<xen-devel@lists.xensource.com>
Subject: Re: getting a 32-bit mfn from a 32-on-64 HVM guest
Date: Sun, 20 Jun 2010 18:56:25 +0100 [thread overview]
Message-ID: <C84414D9.1806B%keir.fraser@eu.citrix.com> (raw)
In-Reply-To: <ab0e05c1-08c2-403d-92af-4528c6dbd982@default>
On 20/06/2010 18:45, "Dan Magenheimer" <dan.magenheimer@oracle.com> wrote:
> What is the "proper" way to ensure that the cmfn
> is properly truncated for a 32-bit HVM guest
> without truncating it for a 64-bit guest? I
> have used is_pv_32on64_vcpu()... is there an equivalent
> for HVM? Or do I need to do something entirely different?
See the x86_64 version of arch/x86/hvm/hvm.c:hvm_do_hypercall() which uses
hvm_guest_x86_mode() to get the 'bitness' of the HVM-guest caller. You
should do the same, probably. Or even have a compat shim around your
hypercall same as others which have differences between 32- and 64-bit
struct layouts, and have the dispatch tables in hvm.c (HVM callers) and
entry.S (PV callers) dispatch to the correct entry point for the bitness of
the caller.
-- Keir
next prev parent reply other threads:[~2010-06-20 17:56 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-06-20 17:45 getting a 32-bit mfn from a 32-on-64 HVM guest Dan Magenheimer
2010-06-20 17:56 ` Keir Fraser [this message]
2010-06-21 1:50 ` Dan Magenheimer
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