Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750910AbaKYPNS (ORCPT ); Tue, 25 Nov 2014 10:13:18 -0500 Received: from smtp02.citrix.com ([66.165.176.63]:48157 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750780AbaKYPNR (ORCPT ); Tue, 25 Nov 2014 10:13:17 -0500 X-IronPort-AV: E=Sophos;i="5.07,456,1413244800"; d="scan'208";a="196587022" Date: Tue, 25 Nov 2014 15:12:14 +0000 From: Stefano Stabellini X-X-Sender: sstabellini@kaball.uk.xensource.com To: Boris Ostrovsky CC: Stefano Stabellini , , , , , Subject: Re: [PATCH v3 1/2] xen/pci: Defer initialization of MSI ops on HVM guests until after x2APIC has been set up In-Reply-To: <54749C2B.4090303@oracle.com> Message-ID: References: <1416870378-32481-1-git-send-email-boris.ostrovsky@oracle.com> <1416870378-32481-2-git-send-email-boris.ostrovsky@oracle.com> <54749C2B.4090303@oracle.com> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" X-DLP: MIA1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 25 Nov 2014, Boris Ostrovsky wrote: > On 11/25/2014 07:06 AM, Stefano Stabellini wrote: > > On Mon, 24 Nov 2014, Boris Ostrovsky wrote: > > > If the hardware supports APIC virtualization we may decide not to use > > > pirqs > > > and instead use APIC/x2APIC directly, meaning that we don't want to set > > > x86_msi.setup_msi_irqs and x86_msi.teardown_msi_irq to Xen-specific > > > routines. > > > However, x2APIC is not set up by the time pci_xen_hvm_init() is called so > > > we > > > need to postpone setting these ops until later, when we know which APIC > > > mode > > > is used. > > > > > > (Note that currently x2APIC is never initialized on HVM guests. This may > > > change in the future) > > I take that this is safe because no MSIs can be received at this point > > (apic_post_init), right? > > > Yes. At the time apic_post_init() is called PCI has not been probed yet. Please add that to the commit message. Acked-by: Stefano Stabellini -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/