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Date: Fri, 16 Dec 2011 15:40:01 +0800
From: Zang Hongyong <zanghongyong@huawei.com>
Subject: Re: [PATCH 0/2] vhot-net: Use kvm_memslots instead of vhost_memory to
 translate GPA to HVA
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To: Sasha Levin <levinsasha928@gmail.com>
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于 2011/12/16,星期五 15:05, Sasha Levin 写道:
> On Fri, 2011-12-16 at 13:32 +0800, zanghongyong@huawei.com wrote:
>> From: Hongyong Zang<zanghongyong@huawei.com>
>>
>> Vhost-net uses its own vhost_memory, which results from user space (qemu) info,
>> to translate GPA to HVA. Since kernel's kvm structure already maintains the
>> address relationship in its member *kvm_memslots*, these patches use kernel's
>> kvm_memslots directly without the need of initialization and maintenance of
>> vhost_memory.
> Conceptually, vhost isn't aware of KVM - it's just a driver which moves
> data from vq to a tap device and back. You can't simply add KVM specific
> code into vhost.
>
> Whats the performance benefit?
>
But vhost-net is only used in virtualization situation. vhost_memory is 
maintained
by user space qemu.
In this way, the memory relationship can be accquired from kernel 
without the
need of maintainence of vhost_memory from qemu.