From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sheng Yang Subject: Re: [PATCH 1/3] KVM: Emulation MSI-X mask bits for assigned devices Date: Mon, 11 Oct 2010 17:32:00 +0800 Message-ID: <201010111732.00553.sheng@linux.intel.com> References: <1285667052-24907-1-git-send-email-sheng@linux.intel.com> <201009301341.36766.sheng@linux.intel.com> <4CA87F14.3030603@redhat.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Marcelo Tosatti , kvm@vger.kernel.org To: Avi Kivity Return-path: Received: from mga11.intel.com ([192.55.52.93]:45036 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753629Ab0JKJb4 (ORCPT ); Mon, 11 Oct 2010 05:31:56 -0400 In-Reply-To: <4CA87F14.3030603@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On Sunday 03 October 2010 21:03:16 Avi Kivity wrote: > On 09/30/2010 07:41 AM, Sheng Yang wrote: > > On Wednesday 29 September 2010 16:36:25 Avi Kivity wrote: > > > On 09/28/2010 11:44 AM, Sheng Yang wrote: > > > > This patch enable per-vector mask for assigned devices using MSI-X. > > > > > > > > + > > > > > > > > struct kvm_assigned_msix_entry { > > > > > > > > __u32 assigned_dev_id; > > > > __u32 gsi; > > > > __u16 entry; /* The index of entry in the MSI-X table */ > > > > > > > > - __u16 padding[3]; > > > > + __u16 flags; > > > > + __u16 padding[2]; > > > > > > > > }; > > > > > > Given that this field wasn't a flag field previously, we can't expect > > > it to be zero. So before we can check it, userspace needs to tell us > > > that is knows the field is not padding, but a flags field. > > > > > > You can use KVM_ENABLE_CAP for that. > > > > OK, I would use it. And it's per vcpu ioctl though, I would like to use > > it on setting for per vm. > > Yes. It's easier to have KVM_ASSIGN_SET_MSIX_ENTRY2 that knows about > the flags field. Well, maybe it's a waste when we still have room in old one... I think KVM_ENABLE_CAP maybe good enough. > > btw, this should be documented in Documentation/kvm/api.txt. OK. -- regards Yang, Sheng