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From: Avi Kivity <avi@redhat.com>
To: Jan Kiszka <jan.kiszka@web.de>
Cc: kvm-devel <kvm@vger.kernel.org>,
	Glauber Costa <glommer@redhat.com>,
	qemu-devel <qemu-devel@nongnu.org>
Subject: Re: [PATCH] kvm: Fix overlapping check for memory slots
Date: Mon, 13 Apr 2009 12:49:28 +0300	[thread overview]
Message-ID: <49E30AA8.1040709@redhat.com> (raw)
In-Reply-To: <49E3090B.2090200@web.de>

Jan Kiszka wrote:
> Avi Kivity wrote:
>   
>> Jan Kiszka wrote:
>>     
>>> This nice little buglet complicates a smarter slot management in qemu
>>> user space just "slightly". Sigh...
>>>
>>> -------->
>>>
>>> When checking for overlapping slots on registration of a new one, kvm
>>> currently also considers zero-length (ie. deleted) slots and rejects
>>> requests incorrectly. This finally denies user space from joining slots.
>>> Fix the check by skipping deleted slots.
>>>   
>>>       
>> Can userspace fail gracefully when the bug is present?  If not, the you
>> should add a KVM_CAP_ to advertise the fix; without the capability don't
>> attempt the smarter slot management.
>>     
>
> I already thought about adding some
> KVM_CAP_DESTROY_MEMORY_REGION_NOW_REALLY_WORKS and skip the workaround
> in [1]. Maybe a good idea, comments welcome.
>
>   

It's a good idea regardless of how qemu handles it.  There can be other 
users.

-- 
error compiling committee.c: too many arguments to function


WARNING: multiple messages have this Message-ID (diff)
From: Avi Kivity <avi@redhat.com>
To: Jan Kiszka <jan.kiszka@web.de>
Cc: Glauber Costa <glommer@redhat.com>,
	qemu-devel <qemu-devel@nongnu.org>,
	kvm-devel <kvm@vger.kernel.org>
Subject: [Qemu-devel] Re: [PATCH] kvm: Fix overlapping check for memory slots
Date: Mon, 13 Apr 2009 12:49:28 +0300	[thread overview]
Message-ID: <49E30AA8.1040709@redhat.com> (raw)
In-Reply-To: <49E3090B.2090200@web.de>

Jan Kiszka wrote:
> Avi Kivity wrote:
>   
>> Jan Kiszka wrote:
>>     
>>> This nice little buglet complicates a smarter slot management in qemu
>>> user space just "slightly". Sigh...
>>>
>>> -------->
>>>
>>> When checking for overlapping slots on registration of a new one, kvm
>>> currently also considers zero-length (ie. deleted) slots and rejects
>>> requests incorrectly. This finally denies user space from joining slots.
>>> Fix the check by skipping deleted slots.
>>>   
>>>       
>> Can userspace fail gracefully when the bug is present?  If not, the you
>> should add a KVM_CAP_ to advertise the fix; without the capability don't
>> attempt the smarter slot management.
>>     
>
> I already thought about adding some
> KVM_CAP_DESTROY_MEMORY_REGION_NOW_REALLY_WORKS and skip the workaround
> in [1]. Maybe a good idea, comments welcome.
>
>   

It's a good idea regardless of how qemu handles it.  There can be other 
users.

-- 
error compiling committee.c: too many arguments to function

  reply	other threads:[~2009-04-13  9:49 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-04-11  9:48 [PATCH] kvm: Fix overlapping check for memory slots Jan Kiszka
2009-04-11  9:48 ` [Qemu-devel] " Jan Kiszka
2009-04-13  5:47 ` Sheng Yang
2009-04-13  5:47   ` [Qemu-devel] " Sheng Yang
2009-04-13  8:50   ` Jan Kiszka
2009-04-13  8:50     ` [Qemu-devel] " Jan Kiszka
2009-04-13  8:53     ` Sheng Yang
2009-04-13  8:53       ` [Qemu-devel] " Sheng Yang
2009-04-13  9:03       ` Jan Kiszka
2009-04-13  9:03         ` [Qemu-devel] " Jan Kiszka
2009-04-13  9:32 ` Avi Kivity
2009-04-13  9:32   ` [Qemu-devel] " Avi Kivity
2009-04-13  9:42   ` Jan Kiszka
2009-04-13  9:42     ` [Qemu-devel] " Jan Kiszka
2009-04-13  9:49     ` Avi Kivity [this message]
2009-04-13  9:49       ` Avi Kivity
2009-04-13  9:59 ` [PATCH v2] " Jan Kiszka
2009-04-13  9:59   ` [Qemu-devel] " Jan Kiszka
2009-04-13 13:04   ` Avi Kivity
2009-04-13 13:04     ` [Qemu-devel] " Avi Kivity

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