From: Mario Smarduch <m.smarduch@samsung.com>
To: kvm-ia64@vger.kernel.org
Subject: Re: [PATCH v12 2/6] KVM: Add generic support for dirty page logging
Date: Thu, 06 Nov 2014 18:07:45 +0000 [thread overview]
Message-ID: <545BB8F1.1060805@samsung.com> (raw)
In-Reply-To: <1414017251-5772-3-git-send-email-m.smarduch@samsung.com>
On 11/06/2014 02:14 AM, Paolo Bonzini wrote:
>
>
> On 06/11/2014 00:05, Mario Smarduch wrote:
>> On 11/05/2014 08:09 AM, Paolo Bonzini wrote:
>>>
>>>
>>> On 01/11/2014 11:12, James Hogan wrote:
>>>> AFAICT all of the arch implementations of kvm_vm_ioctl_get_dirty_log()
>>>> except x86 and ppc hv (i.e. ia60, mips, ppc pv, s390) already make use
>>>> of the existing generic function kvm_get_dirty_log() to help implement
>>>> their kvm_vm_ioctl_get_dirty_log functions, which all look pretty
>>>> similar now except for TLB flushing.
>>>>
>>>> Would they not be a better base for a generic
>>>> kvm_vm_ioctl_get_dirty_log()?
>>>>
>>>> It feels a bit wrong to add a generic higher level function which
>>>> doesn't make use of the existing generic lower level abstraction.
>>>>
>>>> (Appologies if this has already been brought up in previous versions of
>>>> the patchset, I haven't been tracking them).
>>>
>>> I agree that we should make the interface look more like
>>> kvm_get_dirty_log(). Here the steps are:
>>>
>>> + * 1. Take a snapshot of the bit and clear it if needed.
>>> + * 2. Write protect the corresponding page.
>>> + * 3. Flush TLB's if needed.
>>> + * 4. Copy the snapshot to the userspace.
>>
>> Hi Paolo,
>> thanks for breaking it down between generic/architecture layers,
>> helps a lot. Initially I thought we could get TLB flushing to
>> generic layer, previous x86 version worked for ARM. But looking
>> deeper other architectures either use non-generic flush or none
>> at all. Right now we would have x86, ARM, IA64 using generic TLB flush.
>> I'll restructure for another version.
>
> I'll test the swap between 3 and 4 above, and send it to the list. Feel
> free to include it in v13, so that it gets back to me via Christoffer
> and Marc.
>
> Paolo
>
Ok, will do. So it would be kvm/kvm/x86 and 4 armv7 patches.
Mario
prev parent reply other threads:[~2014-11-06 18:07 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-22 22:34 [PATCH v12 2/6] KVM: Add generic support for dirty page logging Mario Smarduch
2014-10-30 12:14 ` Cornelia Huck
2014-10-30 19:19 ` Mario Smarduch
2014-11-01 10:12 ` James Hogan
2014-11-03 3:01 ` Takuya Yoshikawa
2014-11-03 18:44 ` Mario Smarduch
2014-11-03 19:34 ` Mario Smarduch
2014-11-05 16:09 ` Paolo Bonzini
2014-11-05 23:05 ` Mario Smarduch
2014-11-06 10:14 ` Paolo Bonzini
2014-11-06 18:07 ` Mario Smarduch [this message]
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