From mboxrd@z Thu Jan 1 00:00:00 1970 From: Olaf Hering Subject: Re: [PATCH v3] xen/hvm: add kexec/kdump support Date: Mon, 1 Aug 2011 15:28:19 +0200 Message-ID: <20110801132819.GA10226@aepfle.de> References: <20110801124637.GA9564@aepfle.de> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Return-path: Content-Disposition: inline In-Reply-To: <20110801124637.GA9564@aepfle.de> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org On Mon, Aug 01, Olaf Hering wrote: > - add xs_introduce() in xs_init() to shutdown all open watches that the > previous kernel had registered. Without this change the kexec may > crash due to unexpected watch events. > This depends on a xenstored change which has to allow the XS_INTRODUCE > from a guest. > And this part may need more work because the xs_introduce may hang > forever on an old dom0 tool stack The hang I encountered last week was due to a bug in the new xs_introduce() function. "iov[2].iov_len" was by accident written as "iov[3].iov_len", which left the iov_len uninitialized. Then xenstored got a huge iov_len, returned an error which the kernel received. But the process_msg() did not wakeup read_reply() for some reason. Today an unmodified sles11sp1 dom0 can boot a 3.0 kernel with the kexec/kdump patch applied. Olaf