From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keir Fraser Subject: Re: use tasklet to handle init/sipi? Date: Mon, 25 Mar 2013 06:29:04 +0000 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: "Zhang, Yang Z" , "xen-devel@lists.xen.org" Cc: "Zhang, Xiantao" , Jan Beulich List-Id: xen-devel@lists.xenproject.org There are deadlock issues around directly locking and resetting a remote vcpu (e.g., buggy/malicious guest vcpu A sends INIT to vcpu B, and B does same to A). -- Keir On 25/03/2013 05:31, "Zhang, Yang Z" wrote: > Hi, Keir, > > I am looking into a issue and found cs:17457 changes to use tasklet to handle > init and sipi. And the comments only said "clean up". I wonder is there any > special reason to use tasklet to handle it? If no, I will send a patch to call > handler directly instead via tasklet. > The background is that with APICv, it assume all apic write is succeed and > don't care the return value of vlapic_reg_write(). But the above logic need > the caller to check return value. This obviously will break APICv. > > # HG changeset patch > # User Keir Fraser > # Date 1208270873 -3600 > # Node ID e15be54059e4bde8f5916269dedff5fc3812686a > # Parent 6691ae150d104127c097fd9f3a6acccc5ce43c52 > x86, hvm: Clean up handling of APIC INIT and SIPI messages. > Signed-off-by: Keir Fraser > > best regards > yang >