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Date: Wed, 17 Sep 2014 11:38:15 +0300
From: "Michael S. Tsirkin" <mst@redhat.com>
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Subject: [Qemu-devel]  vhost-user: VHOST_SET_MEM_TABLE,
 VHOST_SET_VRING_CALL need a reply?
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To: Linhaifeng <haifeng.lin@huawei.com>
Cc: qemu-devel@nongnu.org, n.nikolaev@virtualopensystems.com, jerry.lilijun@huawei.com

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?