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Date: Mon, 26 Jul 2010 15:41:24 -0500
From: Anthony Liguori <anthony@codemonkey.ws>
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Subject: Re: [Qemu-devel] [PATCH v7 0/4] Inter-VM shared memory device
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To: Avi Kivity <avi@redhat.com>
Cc: Cam Macdonell <cam@cs.ualberta.ca>, qemu-devel@nongnu.org, kvm@vger.kernel.org

On 07/26/2010 03:27 PM, Avi Kivity wrote:
>  On 07/26/2010 10:41 PM, Anthony Liguori wrote:
>>
>> kvm_set_irqfd() is fine, it just needs to be ported.  It should be 
>> there due to vhost though?
>>
>
> It should, but isn't.
>
>> qemu_ram_map() is more difficult.  I would think the better approach 
>> would be to invert things.  Instead of a "give me a stable mapping 
>> that is shared atomically with a guest to this ram region", I would 
>> go with "go create a ram region with this preallocated memory" and 
>> then just assume that afterwards, you can make use of it and it's 
>> exposed as atomic memory.
>
> Isn't that what qemu_ram_map() does?

Yup, name is misleading.  I thought it was the equivalent of 
cpu_physical_memory_map() but took a ram_addr_t instead of a target_ulong.

Regards,

Anthony Liguori

>
>> ram_addr_t qemu_ram_map(DeviceState *dev, const char *name,
>>                         ram_addr_t size, void *host)
>
> 'host' is your "this preallocated memory", no?
>