From: Christian Borntraeger <borntraeger@de.ibm.com>
Organization: IBM
To: Amit Shah <amit.shah@redhat.com>
Subject: Re: [PATCH] virtio_console: Add support for multiple ports for generic guest and host communication
Date: Thu, 1 Oct 2009 11:00:48 +0200
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Cc: Rusty Russell <rusty@rustcorp.com.au>, Alan Cox <alan@linux.intel.com>,
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Am Mittwoch 30 September 2009 19:13:21 schrieb Amit Shah:
> - uses port->id instead of a static hvc_vtermno to pass on a value to
>   hvc_alloc(). Motivation explained within comments in the code.

[...]
> +	 * The first argument of hvc_alloc() is the virtual console
> +	 * number. hvc_alloc() checks if a console with the same value
> +	 * was used in hvc_instantiate(). We may not end up passing
> +	 * the same value here (we use the value 0 in
> +	 * hvc_instantiate() but the console port may not be at id
> +	 * 0). This isn't a problem, though. Nothing in hvc really
> +	 * depends on these numbers and since this number is passed on
> +	 * to us when cons_get/put_chars() is called, it's preferable
> +	 * to pass on the port->id so that we can get the port struct
> +	 * via get_port_from_id().
[...]
> +	port->hvc = hvc_alloc(port->id, 0, &virtio_cons, PAGE_SIZE);

I am not sure if this is going to be ok. 

When I change the old code (without your patch) to use vtermno=0 in 
hvc_instantiate and vtermno=1 in hvc_alloc I get 
"Warning: unable to open an initial console."

It seems to me that we have to pass the same values.

Christian
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