From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sheng Yang Subject: Re: [PATCH 09/10] KVM: Enable MSI for device assignment Date: Tue, 4 Nov 2008 22:57:16 +0800 Message-ID: <20081104145716.GD18696@yukikaze> References: <1225428647-27614-1-git-send-email-sheng@linux.intel.com> <1225428647-27614-10-git-send-email-sheng@linux.intel.com> <49103098.7020109@redhat.com> <20081104132543.GB18696@yukikaze> <49104F01.30604@redhat.com> <20081104135853.GC18696@yukikaze> <49105DA7.3020204@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Sheng Yang , kvm@vger.kernel.org To: Avi Kivity Return-path: Received: from rv-out-0506.google.com ([209.85.198.236]:60891 "EHLO rv-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756143AbYKDO5X (ORCPT ); Tue, 4 Nov 2008 09:57:23 -0500 Received: by rv-out-0506.google.com with SMTP id k40so3320824rvb.1 for ; Tue, 04 Nov 2008 06:57:22 -0800 (PST) Content-Disposition: inline In-Reply-To: <49105DA7.3020204@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On Tue, Nov 04, 2008 at 04:35:19PM +0200, Avi Kivity wrote: > Sheng Yang wrote: >>> In fact, it's not just for pci. We could msi-enable e1000 and get >>> improved performance there as well. >>> >> >> E1000? Don't understand... Sounds like INTx->MSI... >> > > There are msi-capable e1000 cards. If we upgrade qemu's e1000 to > support msi, and if the guest supports msi, it will be msi all the way. Oh, forgot we got e1000 emulation in qemu... > >>>> But I guess what you means is only set >>>> gsi can result in kvm_set_irq() deliver the MSI correctly. I think this can >>>> be done. Associating gsi with guest_msi_addr and guest_msi_data in a linked >>>> list, for gsi >= IOAPIC_PINS, >>>> >>> Let's say, (gsi >> 24) == 1. That gives us 16M potential MSIs. >>> >> >> Confused... GSI become a bitmap? >> > > A structure... > > struct gsi { > u32 n : 24; > u32 type : 8; // 0 -> classic gsi, 1 -> msi > }; I just don't understand why we need 24 bits for n? GSI can be that wide? -- regards Yang, Sheng > > > -- > error compiling committee.c: too many arguments to function > > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html