On Tue, May 20, 2008 at 01:39:26PM +0900, Itsuro ODA wrote: > Hi all, > > On Tue, 20 May 2008 13:58:39 +1000 > Simon Horman <horms@xxxxxxxxxxxx> wrote: > > > On Tue, Apr 22, 2008 at 05:32:03PM +0900, Itsuro ODA wrote: > > > Hi all, > > > > > > Recent version of xen (ex. RHEL5.2, 3.2.0) on the x86_64 > > > moves the physical(machine) address of xen code/data area after > > > the system started up. The start address of this is stored in > > > 'xen_phys_start'. Thus to get a machine address of a xen text symbol > > > from its virtual address, calculate > > > "va - __XEN_VIRT_START + xen_phys_start". > > > > > > crash and makedumpfile command need the value of xen_phys_start. > > > They know the virtual address of 'xen_phys_start' symbol but > > > no way to extract the value of xen_phys_start. > > > > > > I think adding the xen_phys_start value to the CRASHINFO ElfNote > > > section at first. (Plan A: patch for xen hypervisor code attaced) > > > It is smallest modification necessary over all. > > > > > > On the other hand there is a opinion that it is better to upgrade > > > a user-package than a hypervisor or kernel package. > > > The xen_phys_start value can be got from /proc/iomem. > > > ------------------------------------------------------- > > > # cat /proc/iomem > > > ... > > > 7e600000-7f5fffff : Hypervisor code and data *** this line > > > ... > > > ------------------------------------------------------- > > > So the kexec-tools can handle it theoretically. > > > > > > The Plan B is that kexec-tools adds another ElfNote section which > > > holds the xen_phys_start value. The attached patch works well > > > though I am concern about it is a bit tricky. > > > > > > Which plan is better ? Or more good implementation ? > > > Please comment. > > > > > > (note that crash and makedumpfile modification is same degree > > > for both plan.) > > > > Hi Oda-san, > > > > I think that in terms of simplicity plan A is a clear > > winner. That is assuming tha the changes to crash > > and makedumpfile are more or less the same for both > > plan A and plan B. > > The changes to crash and makedumpfile is almost same > for both plan A and plan B. > > Yes, Plan A is simple. > The point under discussion is that the already released > versions of xen need to apply the fix, and from the view point > of the users for such versions they may prefer to update > the kexec-tools rather than the hypervisor. > > > However, if there is a reason that it makes sense to include > > the change in kexec-tools and make a fresh release, I'm happy to do so. > > Thanks. > > I am concerned about the changes of the Plan B is little tricky. > So I will think that the changes become simpler or more reasonable. Yes, i am concerned about that too. -- 宝曼 西門 (ホウマン・サイモン) | Simon Horman (Horms) -- Crash-utility mailing list Crash-utility@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/crash-utility
