From: "Jan Beulich" <JBeulich@suse.com>
To: Julien Grall <julien.grall@arm.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>,
Wei Liu <wei.liu2@citrix.com>,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
George Dunlap <George.Dunlap@eu.citrix.com>,
Andrew Cooper <andrew.cooper3@citrix.com>,
Ian Jackson <Ian.Jackson@eu.citrix.com>, Tim Deegan <tim@xen.org>,
oleksandr_tyshchenko@epam.com,
xen-devel <xen-devel@lists.xenproject.org>,
"andrii_anisov@epam.com" <andrii_anisov@epam.com>,
Roger Pau Monne <roger.pau@citrix.com>
Subject: Re: [PATCH 09/14] xen: Introduce HAS_M2P config and use to protect mfn_to_gmfn call
Date: Fri, 10 May 2019 08:19:31 -0600 [thread overview]
Message-ID: <5CD58873020000780022D9FC@prv1-mh.provo.novell.com> (raw)
In-Reply-To: <9e696d26-0d3b-da9e-7427-f29da07dde7c@arm.com>
>>> On 10.05.19 at 16:04, <julien.grall@arm.com> wrote:
> On 10/05/2019 14:45, Jan Beulich wrote:
>>>>> On 10.05.19 at 15:41, <julien.grall@arm.com> wrote:
>>> The point here, we keep within the hypervisor the idea of what's valid or
>>> invalid. This allows us more flexibility on the value here (imagine we decide to
>>> change the value of GFN_INVALID in the future...).
>>
>> Exactly, and hence INVALID_GFN should not become visible to the
>> outside. Hence my request to use an all-ones value here.
> It is only visible if you put an exact value in the documentation. Your
> suggestion is to put a exactly value and I would rather not see that.
I did specifically suggest to _not_ store INVALID_GFN here, but to
store 64-bit bits of ones. Note the difference between the two on
32-bit Arm.
>>>>> Well, it at least tell you the function can't work. So I think it is still makes
>>>>> sense to have it.
>>>>
>>>> I disagree.
>>> You disagree because...?
>>
>> Because of what I've said in my initial reply (still quoted above).
>
> I still don't see the problem of unconditional log message. It is not really the
> first place we have that.
>
>>
>>> I hope you are aware, this is unlikely going to be printed as the code should
>>> not be called.
>>
>> ASSERT_UNREACHABLE() then?
>
> And still avoiding the printk?
Preferably yes; depends on how exactly you code the assertion.
If you follow the if()-ASSERT_UNREACHABLE()-return style we've
been using elsewhere, then no matter how you place the #else
or #endif the printk() will be compiled out.
Jan
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Xen-devel mailing list
Xen-devel@lists.xenproject.org
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WARNING: multiple messages have this Message-ID (diff)
From: "Jan Beulich" <JBeulich@suse.com>
To: "Julien Grall" <julien.grall@arm.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>,
Wei Liu <wei.liu2@citrix.com>,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
George Dunlap <George.Dunlap@eu.citrix.com>,
Andrew Cooper <andrew.cooper3@citrix.com>,
Ian Jackson <Ian.Jackson@eu.citrix.com>, Tim Deegan <tim@xen.org>,
oleksandr_tyshchenko@epam.com,
xen-devel <xen-devel@lists.xenproject.org>,
"andrii_anisov@epam.com" <andrii_anisov@epam.com>,
Roger Pau Monne <roger.pau@citrix.com>
Subject: Re: [Xen-devel] [PATCH 09/14] xen: Introduce HAS_M2P config and use to protect mfn_to_gmfn call
Date: Fri, 10 May 2019 08:19:31 -0600 [thread overview]
Message-ID: <5CD58873020000780022D9FC@prv1-mh.provo.novell.com> (raw)
Message-ID: <20190510141931.ysACByrzNpdr7EpYjNQyL_mTIbW-TcoZEVx56IgCyk8@z> (raw)
In-Reply-To: <9e696d26-0d3b-da9e-7427-f29da07dde7c@arm.com>
>>> On 10.05.19 at 16:04, <julien.grall@arm.com> wrote:
> On 10/05/2019 14:45, Jan Beulich wrote:
>>>>> On 10.05.19 at 15:41, <julien.grall@arm.com> wrote:
>>> The point here, we keep within the hypervisor the idea of what's valid or
>>> invalid. This allows us more flexibility on the value here (imagine we decide to
>>> change the value of GFN_INVALID in the future...).
>>
>> Exactly, and hence INVALID_GFN should not become visible to the
>> outside. Hence my request to use an all-ones value here.
> It is only visible if you put an exact value in the documentation. Your
> suggestion is to put a exactly value and I would rather not see that.
I did specifically suggest to _not_ store INVALID_GFN here, but to
store 64-bit bits of ones. Note the difference between the two on
32-bit Arm.
>>>>> Well, it at least tell you the function can't work. So I think it is still makes
>>>>> sense to have it.
>>>>
>>>> I disagree.
>>> You disagree because...?
>>
>> Because of what I've said in my initial reply (still quoted above).
>
> I still don't see the problem of unconditional log message. It is not really the
> first place we have that.
>
>>
>>> I hope you are aware, this is unlikely going to be printed as the code should
>>> not be called.
>>
>> ASSERT_UNREACHABLE() then?
>
> And still avoiding the printk?
Preferably yes; depends on how exactly you code the assertion.
If you follow the if()-ASSERT_UNREACHABLE()-return style we've
been using elsewhere, then no matter how you place the #else
or #endif the printk() will be compiled out.
Jan
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Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel
next prev parent reply other threads:[~2019-05-10 14:19 UTC|newest]
Thread overview: 154+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-07 15:14 [PATCH 00/14] xen/arm: Properly disable M2P on Arm Julien Grall
2019-05-07 15:14 ` [Xen-devel] " Julien Grall
2019-05-07 15:14 ` [PATCH 01/14] xen/arm: Use mfn_to_pdx instead of pfn_to_pdx when possible Julien Grall
2019-05-07 15:14 ` [Xen-devel] " Julien Grall
2019-05-09 17:50 ` Stefano Stabellini
2019-05-09 17:50 ` [Xen-devel] " Stefano Stabellini
2019-05-07 15:14 ` [PATCH 02/14] xen/x86: Constify the parameter "d" in mfn_to_gfn Julien Grall
2019-05-07 15:14 ` [Xen-devel] " Julien Grall
2019-05-07 15:14 ` [PATCH 03/14] xen/x86: Make mfn_to_gfn typesafe Julien Grall
2019-05-07 15:14 ` [Xen-devel] " Julien Grall
2019-05-10 11:35 ` Jan Beulich
2019-05-10 11:35 ` [Xen-devel] " Jan Beulich
2019-05-10 13:02 ` Julien Grall
2019-05-10 13:02 ` [Xen-devel] " Julien Grall
2019-05-10 13:24 ` Jan Beulich
2019-05-10 13:24 ` [Xen-devel] " Jan Beulich
2019-05-10 13:25 ` Julien Grall
2019-05-10 13:25 ` [Xen-devel] " Julien Grall
2019-05-20 15:13 ` Julien Grall
2019-05-20 15:13 ` [Xen-devel] " Julien Grall
2019-05-28 17:29 ` George Dunlap
2019-05-28 17:29 ` [Xen-devel] " George Dunlap
2019-05-29 11:39 ` Julien Grall
2019-05-29 11:39 ` [Xen-devel] " Julien Grall
2019-05-07 15:14 ` [PATCH 04/14] xen/x86: Use mfn_to_gfn rather than mfn_to_gmfn Julien Grall
2019-05-07 15:14 ` [Xen-devel] " Julien Grall
2019-05-10 12:15 ` Jan Beulich
2019-05-10 12:15 ` [Xen-devel] " Jan Beulich
2019-05-10 13:07 ` Julien Grall
2019-05-10 13:07 ` [Xen-devel] " Julien Grall
2019-05-07 15:14 ` [PATCH 05/14] xen/grant-table: Make arch specific macros typesafe Julien Grall
2019-05-07 15:14 ` [Xen-devel] " Julien Grall
2019-05-09 17:54 ` Stefano Stabellini
2019-05-09 17:54 ` [Xen-devel] " Stefano Stabellini
2019-05-07 15:14 ` [PATCH 06/14] xen: Convert hotplug page function to use typesafe MFN Julien Grall
2019-05-07 15:14 ` [Xen-devel] " Julien Grall
2019-05-09 18:01 ` Stefano Stabellini
2019-05-09 18:01 ` [Xen-devel] " Stefano Stabellini
2019-05-09 18:10 ` Julien Grall
2019-05-09 18:10 ` [Xen-devel] " Julien Grall
2019-05-07 15:14 ` [PATCH 07/14] xen: Convert is_xen_fixed_mfn " Julien Grall
2019-05-07 15:14 ` [Xen-devel] " Julien Grall
2019-05-24 15:16 ` George Dunlap
2019-05-24 15:16 ` [Xen-devel] " George Dunlap
2019-05-07 15:14 ` [PATCH 08/14] xen: Convert is_xen_heap_mfn " Julien Grall
2019-05-07 15:14 ` [Xen-devel] " Julien Grall
2019-05-24 15:15 ` George Dunlap
2019-05-24 15:15 ` [Xen-devel] " George Dunlap
2019-05-07 15:14 ` [PATCH 09/14] xen: Introduce HAS_M2P config and use to protect mfn_to_gmfn call Julien Grall
2019-05-07 15:14 ` [Xen-devel] " Julien Grall
2019-05-09 18:06 ` Stefano Stabellini
2019-05-09 18:06 ` [Xen-devel] " Stefano Stabellini
2019-05-09 18:12 ` Julien Grall
2019-05-09 18:12 ` [Xen-devel] " Julien Grall
2019-05-09 18:16 ` Stefano Stabellini
2019-05-09 18:16 ` [Xen-devel] " Stefano Stabellini
2019-05-09 18:29 ` Julien Grall
2019-05-09 18:29 ` [Xen-devel] " Julien Grall
2019-05-09 19:49 ` Stefano Stabellini
2019-05-09 19:49 ` [Xen-devel] " Stefano Stabellini
2019-05-10 12:31 ` Jan Beulich
2019-05-10 12:31 ` [Xen-devel] " Jan Beulich
2019-05-10 13:22 ` Julien Grall
2019-05-10 13:22 ` [Xen-devel] " Julien Grall
2019-05-10 13:32 ` Jan Beulich
2019-05-10 13:32 ` [Xen-devel] " Jan Beulich
2019-05-10 13:41 ` Julien Grall
2019-05-10 13:41 ` [Xen-devel] " Julien Grall
2019-05-10 13:45 ` Jan Beulich
2019-05-10 13:45 ` [Xen-devel] " Jan Beulich
2019-05-10 14:04 ` Julien Grall
2019-05-10 14:04 ` [Xen-devel] " Julien Grall
2019-05-10 14:19 ` Jan Beulich [this message]
2019-05-10 14:19 ` Jan Beulich
2019-05-10 14:34 ` Julien Grall
2019-05-10 14:34 ` [Xen-devel] " Julien Grall
2019-05-22 16:03 ` Julien Grall
2019-05-22 16:03 ` [Xen-devel] " Julien Grall
2019-05-07 15:14 ` [PATCH 10/14] xen: Remove mfn_to_gmfn macro Julien Grall
2019-05-07 15:14 ` [Xen-devel] " Julien Grall
2019-05-07 15:14 ` [PATCH 11/14] xen/x86: mm: Re-implement set_gpfn_from_mfn() as a static inline function Julien Grall
2019-05-07 15:14 ` [Xen-devel] " Julien Grall
2019-05-10 12:43 ` Jan Beulich
2019-05-10 12:43 ` [Xen-devel] " Jan Beulich
2019-05-10 13:27 ` Julien Grall
2019-05-10 13:27 ` [Xen-devel] " Julien Grall
2019-05-10 13:35 ` Jan Beulich
2019-05-10 13:35 ` [Xen-devel] " Jan Beulich
2019-05-10 13:41 ` Julien Grall
2019-05-10 13:41 ` [Xen-devel] " Julien Grall
2019-05-10 13:48 ` Jan Beulich
2019-05-10 13:48 ` [Xen-devel] " Jan Beulich
2019-05-10 14:05 ` Julien Grall
2019-05-10 14:05 ` [Xen-devel] " Julien Grall
2019-05-10 14:21 ` Jan Beulich
2019-05-10 14:21 ` [Xen-devel] " Jan Beulich
2019-05-10 14:48 ` Julien Grall
2019-05-10 14:48 ` [Xen-devel] " Julien Grall
2019-05-07 15:14 ` [PATCH 12/14] xen/x86: pv: Convert update_intpte() to use typesafe MFN Julien Grall
2019-05-07 15:14 ` [Xen-devel] " Julien Grall
2019-05-10 12:54 ` Jan Beulich
2019-05-10 12:54 ` [Xen-devel] " Jan Beulich
2019-05-10 13:28 ` Julien Grall
2019-05-10 13:28 ` [Xen-devel] " Julien Grall
2019-05-07 15:14 ` [PATCH 13/14] xen/mm: Convert {s, g}et_gpfn_from_mfn() " Julien Grall
2019-05-07 15:14 ` [Xen-devel] " Julien Grall
2019-05-07 20:27 ` Tamas K Lengyel
2019-05-07 20:27 ` [Xen-devel] " Tamas K Lengyel
2019-05-09 18:19 ` Stefano Stabellini
2019-05-09 18:19 ` [Xen-devel] " Stefano Stabellini
2019-05-10 13:21 ` Jan Beulich
2019-05-10 13:21 ` [Xen-devel] " Jan Beulich
2019-05-10 13:27 ` Andrew Cooper
2019-05-10 13:27 ` [Xen-devel] " Andrew Cooper
2019-05-10 13:34 ` Julien Grall
2019-05-10 13:34 ` [Xen-devel] " Julien Grall
2019-05-10 13:41 ` Jan Beulich
2019-05-10 13:41 ` [Xen-devel] " Jan Beulich
2019-05-10 13:46 ` Julien Grall
2019-05-10 13:46 ` [Xen-devel] " Julien Grall
2019-05-10 14:02 ` Jan Beulich
2019-05-10 14:02 ` [Xen-devel] " Jan Beulich
2019-05-10 14:05 ` Andrew Cooper
2019-05-10 14:05 ` [Xen-devel] " Andrew Cooper
2019-05-10 14:08 ` Julien Grall
2019-05-10 14:08 ` [Xen-devel] " Julien Grall
2019-05-10 14:09 ` Andrew Cooper
2019-05-10 14:09 ` [Xen-devel] " Andrew Cooper
2019-05-10 14:14 ` Jan Beulich
2019-05-10 14:14 ` [Xen-devel] " Jan Beulich
2019-05-10 14:27 ` Andrew Cooper
2019-05-10 14:27 ` [Xen-devel] " Andrew Cooper
2019-05-24 16:24 ` George Dunlap
2019-05-24 16:24 ` [Xen-devel] " George Dunlap
2019-05-29 16:27 ` Julien Grall
2019-05-29 16:27 ` [Xen-devel] " Julien Grall
2019-05-29 16:29 ` George Dunlap
2019-05-29 16:29 ` [Xen-devel] " George Dunlap
2019-05-24 16:35 ` George Dunlap
2019-05-24 16:35 ` [Xen-devel] " George Dunlap
2019-05-07 15:14 ` [PATCH 14/14] xen/mm: Provide dummy M2P-related helpers when !CONFIG_HAVE_M2P Julien Grall
2019-05-07 15:14 ` [Xen-devel] " Julien Grall
2019-05-09 18:20 ` Stefano Stabellini
2019-05-09 18:20 ` [Xen-devel] " Stefano Stabellini
2019-05-10 13:28 ` Jan Beulich
2019-05-10 13:28 ` [Xen-devel] " Jan Beulich
2019-05-10 13:29 ` Julien Grall
2019-05-10 13:29 ` [Xen-devel] " Julien Grall
2019-05-10 13:37 ` Jan Beulich
2019-05-10 13:37 ` [Xen-devel] " Jan Beulich
2019-05-10 13:38 ` Julien Grall
2019-05-10 13:38 ` [Xen-devel] " Julien Grall
2019-05-24 16:51 ` George Dunlap
2019-05-24 16:51 ` [Xen-devel] " George Dunlap
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