From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Vrabel Subject: Re: [PATCHv6 0/10] kexec: extend kexec hypercall for use with pv-ops kernels Date: Wed, 26 Jun 2013 10:44:11 +0100 Message-ID: <51CAB7EB.6070704@citrix.com> References: <1372095741-27012-1-git-send-email-david.vrabel@citrix.com> <20130625192710.GC10322@debian70-amd64.local.net-space.pl> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20130625192710.GC10322@debian70-amd64.local.net-space.pl> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Daniel Kiper Cc: Keir Fraser , xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org On 25/06/13 20:27, Daniel Kiper wrote: > On Mon, Jun 24, 2013 at 06:42:11PM +0100, David Vrabel wrote: > > [...] > >> Changes since v4 (v5 was not posted to the list): >> >> - _rsvd -> _pad in one of the public ABI structures. >> - Fix bug where trailing pages were not zeroed. This fixes loading a >> 64-bit Linux kernel using a more recent version of kexec-tools. > > Why? I do not see why trailing pages must be zeroed. I am afraid that > this way you are only masking bug in kexec-tools. I think it is better > to do bisect on it and find out which patch introduces a bug. The load sub-ob is defined such that the range (dest_maddr + buf_size, dest_maddr + dest_size] is zeroed. If the caller asks for lots of trailing zeros then we should do this (regardless of how pointless this is). I do note that this is not very well documented and I will improve this. kexec-tools calculates the checksum of the image including the trailing zeroed region which is why the exec would fail. If you want to improve kexec-tools to load fewer zeroed pages, be my guest. > Please prepare next version of these patches and repost with > kexec-tools patches. They are integral part of new Xen kexec > implementation and it is worth to review both patch series together. The kexec-tools patches haven't changed and I don't see any merit in reposting them until the Xen patches are applied. David