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From: Avi Kivity <avi@redhat.com>
To: Cam Macdonell <cam@cs.ualberta.ca>
Cc: Anthony Liguori <anthony@codemonkey.ws>, kvm@vger.kernel.org
Subject: Re: [PATCH] Add shared memory PCI device that shares a memory object betweens VMs
Date: Thu, 02 Apr 2009 10:07:36 +0300	[thread overview]
Message-ID: <49D46438.7040501@redhat.com> (raw)
In-Reply-To: <49D3CF4B.7050500@cs.ualberta.ca>

Cam Macdonell wrote:
> I think there is value for static memory sharing.   It can be used for 
> fast, simple synchronization and communication between guests (and the 
> host) that use need to share data that needs to be updated frequently 
> (such as a simple cache or notification system).  It may not be a 
> common task, but I think static sharing has its place and that's what 
> this device is for at this point.

It would be good to detail a use case for reference.


>> Then you need a side channel to communicate the information to the 
>> guest.
>
> Couldn't one of the registers in BAR0 be used to store the actual 
> (non-power-of-two) size?

The PCI config space (where the BARs reside) is a good place for it.  
Registers 0x40+ are device specific IIRC.

-- 
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.


  reply	other threads:[~2009-04-02  7:07 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-04-01 15:43 [PATCH] Add shared memory PCI device that shares a memory object betweens VMs Cam Macdonell
2009-04-01 16:29 ` Anthony Liguori
2009-04-01 18:07   ` Avi Kivity
2009-04-01 18:52     ` Anthony Liguori
2009-04-01 20:32       ` Cam Macdonell
2009-04-02  7:07         ` Avi Kivity [this message]
2009-04-03 16:54           ` Cam Macdonell
2009-04-02  7:05       ` Avi Kivity
2009-04-19  5:22       ` Cameron Macdonell
2009-04-19 10:26         ` Avi Kivity
     [not found]           ` <f3b32c250904202348t6514d3efjc691b48c4dafe76a@mail.gmail.com>
2009-04-22 22:41             ` Cam Macdonell
     [not found]               ` <f3b32c250904222355y687c39ecl11c52267a1ea7386@mail.gmail.com>
2009-04-23 16:28                 ` Cam Macdonell

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