From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ingo Molnar Subject: Re: [PATCH v5 2/5] KVM: VMX: Register a new IPI for posted interrupt Date: Fri, 8 Mar 2013 14:26:25 +0100 Message-ID: <20130308132625.GA27750@gmail.com> References: <1362705801-4467-1-git-send-email-yang.z.zhang@intel.com> <1362705801-4467-3-git-send-email-yang.z.zhang@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: kvm@vger.kernel.org, gleb@redhat.com, mtosatti@redhat.com, xiantao.zhang@intel.com, hpa@linux.intel.com To: Yang Zhang Return-path: Received: from mail-ee0-f42.google.com ([74.125.83.42]:47564 "EHLO mail-ee0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753185Ab3CHN0b (ORCPT ); Fri, 8 Mar 2013 08:26:31 -0500 Received: by mail-ee0-f42.google.com with SMTP id b47so1004628eek.1 for ; Fri, 08 Mar 2013 05:26:29 -0800 (PST) Content-Disposition: inline In-Reply-To: <1362705801-4467-3-git-send-email-yang.z.zhang@intel.com> Sender: kvm-owner@vger.kernel.org List-ID: * Yang Zhang wrote: > diff --git a/arch/x86/kernel/irqinit.c b/arch/x86/kernel/irqinit.c > index 6e03b0d..2329a54 100644 > --- a/arch/x86/kernel/irqinit.c > +++ b/arch/x86/kernel/irqinit.c > @@ -205,6 +205,10 @@ static void __init apic_intr_init(void) > > /* IPI for X86 platform specific use */ > alloc_intr_gate(X86_PLATFORM_IPI_VECTOR, x86_platform_ipi); > +#ifdef CONFIG_HAVE_KVM > + /* IPI for KVM to deliver posted interrupt */ > + alloc_intr_gate(POSTED_INTR_VECTOR, kvm_posted_intr_ipi); > +#endif Please avoid wasting an IDT entry by reusing x86_platform_ipi. A KVM guest is in essence one type of 'x86 platform', and this callback is used by hardware platforms, so collision is not an issue AFAICS. Thanks, Ingo