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From: Juan Quintela <quintela@redhat.com>
In-Reply-To: <1434043048-4444-7-git-send-email-dgilbert@redhat.com> (David
	Alan Gilbert's message of "Thu, 11 Jun 2015 18:17:22 +0100")
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	<1434043048-4444-7-git-send-email-dgilbert@redhat.com>
Date: Wed, 01 Jul 2015 10:43:47 +0200
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Subject: Re: [Qemu-devel] [PATCH v2 06/12] Translate offsets to destination
	address space
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To: "Dr. David Alan Gilbert (git)" <dgilbert@redhat.com>
Cc: amit.shah@redhat.com, arei.gonglei@huawei.com, qemu-devel@nongnu.org, mrhines@us.ibm.com

"Dr. David Alan Gilbert (git)" <dgilbert@redhat.com> wrote:
> From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
>
> The 'offset' field in RDMACompress and 'current_addr' field
> in RDMARegister are commented as being offsets within a particular
> RAMBlock, however they appear to actually be offsets within the
> ram_addr_t space.
>
> The code currently assumes that the offsets on the source/destination
> match, this change removes the need for the assumption for these
> structures by translating the addresses into the ram_addr_t space of
> the destination host.
>
> Note: An alternative would be to change the fields to actually
> take the data they're commented for; this would potentially be
> simpler but would break stream compatibility for those cases
> that currently work.
>
> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

Reviewed-by: Juan Quintela <quintela@redhat.com>


backwards compatibility, you will live with your errors forever....

> +        /*
> +         * current_addr as passed in is an address in the local ram_addr_t
> +         * space, we need to translate this for the destination
> +         */
> +        reg->key.current_addr -= local_block->offset;
> +        reg->key.current_addr += rdma->dest_blocks[reg->current_index].offset;

I would add a function that is: rdma_adjust_offest() or something, but
it needs three pointer parameters, not sure that it is any easier :-(