From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeremy Fitzhardinge Subject: Re: [PATCH 00 of 38] xen: add more Xen dom0 support Date: Mon, 23 Mar 2009 09:27:48 -0700 Message-ID: <49C7B884.90306@goop.org> References: Mime-Version: 1.0 Content-Type: text/plain; charset=GB2312 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: "Jiang, Yunhong" Cc: Xen-devel List-Id: xen-devel@lists.xenproject.org Jiang, Yunhong wrote: > We are working on the MSI support now. I'd get some guide on how the pirq is defined in pv dom0, can I assume it is something like xen interrupt controller's gsi? The pirq we pass to Xen is the Linux irq we allocate for the interrupt source. For compatibility with native, we maintain an irq == gsi identity, so the Xen pirq will also equal the gsi. However, there's no problem in allocating irqs above the highest gsi for msi use; you could either adapt xen_allocate_pirq or add an msi variant. I think the first is preferred if possible; you'd just use "gsi" to refer to msis too, if they have easily distinguished identifiers. Are you thinking of putting a Xen hook in setup_msi_irq? Thanks, J