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From: Julien Grall <julien.grall@linaro.org>
To: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: xen-devel@lists.xenproject.org, tim@xen.org,
	ian.campbell@citrix.com, stefano.stabellini@citrix.com
Subject: Re: [PATCH] xen/arm: Implement domain_get_maximum_gpfn
Date: Tue, 01 Jul 2014 19:36:17 +0100	[thread overview]
Message-ID: <53B2FFA1.4050007@linaro.org> (raw)
In-Reply-To: <alpine.DEB.2.02.1407011756400.8923@kaball.uk.xensource.com>



On 01/07/14 17:57, Stefano Stabellini wrote:
> On Tue, 1 Jul 2014, Julien Grall wrote:
>> The function domain_get_maximum_gpfn is returning the maximum gpfn ever
>> mapped in the guest. We can use d->arch.p2m.max_mapped_gfn for this purpose.
>>
>> Signed-off-by: Julien Grall <julien.grall@linaro.org>
>
> Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

Thanks. Just a quick follow-up on your question on IRC.

LPAE supports up to 48 bits on ARMv8 (40 bits on v7), so the MFN will 
just fit in 32 bits.

I'm a bit worry about what happen if there is an error? The current 
hypercall doesn't look like to be safe for that. Indeed, the return 
value is used to store the higher gpfn. If the guest also use internal 
error, then we are screw.

This is mostly an issue when the toolstack is running in 32 bits guest 
on 64 bits hypervisor. How x86 support this case?

Stefano was suggesting to introduce a new hypercall 
XENMEM_maximum_gpfn_v2 which will take a pointer to a gpfn in parameter.

Regards,

-- 
Julien Grall

  reply	other threads:[~2014-07-01 18:36 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-07-01 14:57 [PATCH] xen/arm: Implement domain_get_maximum_gpfn Julien Grall
2014-07-01 16:57 ` Stefano Stabellini
2014-07-01 18:36   ` Julien Grall [this message]
2014-07-01 18:53     ` Andrew Cooper
2014-07-09 11:38   ` Julien Grall
2014-07-16 16:02     ` Ian Campbell
2014-07-16 18:17       ` Julien Grall
2014-09-01 21:32       ` Julien Grall
2014-09-03  8:44         ` Ian Campbell
2014-09-03  9:00           ` Tamas K Lengyel
2014-09-08 20:43             ` Julien Grall
2014-09-08 20:47               ` Tamas K Lengyel
2014-09-09 12:50                 ` Tamas K Lengyel
2014-09-09 13:09                   ` Andrew Cooper
2014-09-09 14:01                     ` Tamas K Lengyel
2014-09-10 11:21                 ` Tamas K Lengyel
2014-07-02  9:12 ` Ian Campbell
2014-07-02  9:19   ` Julien Grall
2014-07-02  9:22     ` Ian Campbell
2014-07-02  9:37       ` Julien Grall
2014-07-02  9:41         ` Ian Campbell
2014-07-02  9:50           ` Jan Beulich
2014-07-02  9:52             ` Ian Campbell
2014-07-02 10:19             ` Roger Pau Monné
2014-07-02 10:31               ` Jan Beulich
2014-07-02 10:51                 ` Roger Pau Monné
2014-07-02 10:52                   ` Ian Campbell
2014-07-02 10:58                     ` Andrew Cooper
2014-07-02 11:21                       ` Ian Campbell
2014-07-02 13:44                 ` Konrad Rzeszutek Wilk

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