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Re: [Qemu-devel] vhost-user: VHOST_SET_MEM_TABLE, VHOST_SET_VRING_CALL n
From: |
Linhaifeng |
Subject: |
Re: [Qemu-devel] vhost-user: VHOST_SET_MEM_TABLE, VHOST_SET_VRING_CALL need a reply? |
Date: |
Thu, 18 Sep 2014 08:45:37 +0800 |
User-agent: |
Mozilla/5.0 (Windows NT 6.1; rv:31.0) Gecko/20100101 Thunderbird/31.1.0 |
On 2014/9/17 17:56, Michael S. Tsirkin wrote:
> On Wed, Sep 17, 2014 at 05:39:04PM +0800, Linhaifeng wrote:
>> I think maybe is not need for the backend to wait for response.
>>
>> There is another way.vhost-user send "VHOST_GET_MEM_TABLE" to qemu then qemu
>> send VHOST_SET_MEM_TABLE to update the regions of vhost-user.same as other
>> command.
>> If qemu could response the request of the vhost-user.the vhost-user could
>> update date at anytime.
>
> The updates are initiated by QEMU, as a result of IOMMU,
> memory hotplug or some other configuration change.
How to deal with the vhost-user restart?
when vhost-user restart it will lost the infomation which QEMU send.
In the kernel mode vhost will restart with QEMU but in the user mode vhost will
not.
>
>> I think it's very useful for Commercialization.
>>
>> On 2014/9/17 16:38, Michael S. Tsirkin wrote:
>>> Reply-To:
>>>
>>> Thinking about the vhost-user protocol, VHOST_SET_MEM_TABLE
>>> is used to update the memory mappings.
>>>
>>> So shouldn't we want for response?
>>> Otherwise e.g. guest can start using the memory
>>> that vhost-user can't access.
>>>
>>> Similarly, with an IOMMU vhost-user might access memory it shouldn't.
>>>
>>> VHOST_SET_VRING_CALL is used for MSI-X masking.
>>> Again, after vector is masted by switching the call fd,
>>> backend shouldn't assert the old one.
>>>
>>> Thoughts?
>>>
>>>
>
> .
>
- [Qemu-devel] vhost-user: VHOST_SET_MEM_TABLE, VHOST_SET_VRING_CALL need a reply?, Michael S. Tsirkin, 2014/09/17
- Re: [Qemu-devel] vhost-user: VHOST_SET_MEM_TABLE, VHOST_SET_VRING_CALL need a reply?, Linhaifeng, 2014/09/17
- Re: [Qemu-devel] vhost-user: VHOST_SET_MEM_TABLE, VHOST_SET_VRING_CALL need a reply?, Michael S. Tsirkin, 2014/09/17
- Re: [Qemu-devel] vhost-user: VHOST_SET_MEM_TABLE, VHOST_SET_VRING_CALL need a reply?,
Linhaifeng <=
- Re: [Qemu-devel] vhost-user: VHOST_SET_MEM_TABLE, VHOST_SET_VRING_CALL need a reply?, Michael S. Tsirkin, 2014/09/18
- Re: [Qemu-devel] vhost-user: VHOST_SET_MEM_TABLE, VHOST_SET_VRING_CALL need a reply?, Linhaifeng, 2014/09/18
- Re: [Qemu-devel] vhost-user: VHOST_SET_MEM_TABLE, VHOST_SET_VRING_CALL need a reply?, Michael S. Tsirkin, 2014/09/18
- Re: [Qemu-devel] vhost-user: VHOST_SET_MEM_TABLE, VHOST_SET_VRING_CALL need a reply?, Linhaifeng, 2014/09/17
- Re: [Qemu-devel] vhost-user: VHOST_SET_MEM_TABLE, VHOST_SET_VRING_CALL need a reply?, Michael S. Tsirkin, 2014/09/18