From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony Liguori Subject: Re: [PATCH RFC] Driver to support shared memory with interrupts with broadcast Date: Thu, 30 Jul 2009 13:29:52 -0500 Message-ID: <4A71E6A0.2080601@codemonkey.ws> References: <1248972607-8818-1-git-send-email-cam@cs.ualberta.ca> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org To: Cam Macdonell Return-path: Received: from qw-out-2122.google.com ([74.125.92.25]:29523 "EHLO qw-out-2122.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751313AbZG3S3y (ORCPT ); Thu, 30 Jul 2009 14:29:54 -0400 Received: by qw-out-2122.google.com with SMTP id 8so894563qwh.37 for ; Thu, 30 Jul 2009 11:29:54 -0700 (PDT) In-Reply-To: <1248972607-8818-1-git-send-email-cam@cs.ualberta.ca> Sender: kvm-owner@vger.kernel.org List-ID: Cam Macdonell wrote: > This driver allows the guest VM to access shared memory between other guest > that is a POSIX shared memory object on the host. The driver can also send > interrupts by writing to the DoorBell register. > > With interrupts, the ioctl must specify the ID of the VM to receive the > interrupt or '255' for broadcast to all active VMs. The 'arg' parameter is the > destination VM and 'cmd' is the interrupt code. The value written to the > register is a bit messy. 32-bits are written to the register, the upper 16 are > the destination VM, and the lower 16 are the interrupt 'code' that the > destination guest will receive. Implemented codes (see the interrupt handler) > either call up on the device's semaphore or wake up on the wait_event queue. > These codes' uses are at the discretion of the driver so they could be > customized. > > For ioctls that read values from the device (such as for getting the global ID > of the guest) the arg parameter is unused. > > Cam > I think you should just use Michael's uio_pci driver. I don't think we have a need for a new kernel interface. Regards, Anthony Liguori