From: Andrew Cooper <andrew.cooper3@citrix.com>
To: Oleksandr Andrushchenko <andr2000@gmail.com>,
Xen-devel <xen-devel@lists.xen.org>
Subject: Re: __vmap multiple times same mfn
Date: Tue, 28 Feb 2017 20:51:40 +0000 [thread overview]
Message-ID: <c9afed1e-127c-5864-f5f9-0850305d79ab@citrix.com> (raw)
In-Reply-To: <57fe6170-c11c-2496-4737-bd237a972dbf@gmail.com>
On 28/02/17 19:50, Oleksandr Andrushchenko wrote:
> Hi, all!
>
> I have a use-case when I may need to call __vmap for kernel provided
> IPAs (read MFNs)
>
> which may not be PAGE_SIZE aligned etc.
>
> The question is if it is safe to call __vmap multiple times for
> different IPAs
>
> sharing the same page (mfn), e.g. map something like 6ca00 0080 and
> 6ca00 00a0?
What are you trying to do?
You specifically can use vmap to make non-contiguous MFNs end up
contiguous in virtual address space.
The mappings themselves are of course on page boundaries, so you can't
make a non-page-aligned thing appear aligned.
~Andrew
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next prev parent reply other threads:[~2017-02-28 20:51 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-02-28 19:50 __vmap multiple times same mfn Oleksandr Andrushchenko
2017-02-28 20:51 ` Andrew Cooper [this message]
2017-03-01 5:39 ` Oleksandr Andrushchenko
2017-03-01 8:22 ` Jan Beulich
2017-03-01 8:25 ` Oleksandr Andrushchenko
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