Re: [Qemu-devel] [PATCH v7 0/4] Inter-VM shared memory device

[Anthony Liguori]

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?