> -----Original Message----- > From: Jan Beulich [mailto:jbeul...@suse.com] > Sent: 07 June 2017 13:56 > To: Paul Durrant <paul.durr...@citrix.com> > Cc: Julien Grall (julien.gr...@arm.com) <julien.gr...@arm.com>; Andrew > Cooper <andrew.coop...@citrix.com>; xen-devel(xen- > de...@lists.xenproject.org) <xen-de...@lists.xenproject.org>; > 'BorisOstrovsky' <boris.ostrov...@oracle.com>; Juergen Gross > <jgr...@suse.com> > Subject: RE: [Xen-devel] debian stretch dom0 + xen 4.9 fails to boot > > >>> On 07.06.17 at 14:46, <paul.durr...@citrix.com> wrote: > >> -----Original Message----- > >> From: Jan Beulich [mailto:jbeul...@suse.com] > >> Sent: 07 June 2017 13:00 > >> To: Paul Durrant <paul.durr...@citrix.com> > >> Cc: Julien Grall (julien.gr...@arm.com) <julien.gr...@arm.com>; Andrew > >> Cooper <andrew.coop...@citrix.com>; xen-devel(xen- > >> de...@lists.xenproject.org) <xen-de...@lists.xenproject.org>; > >> 'BorisOstrovsky' <boris.ostrov...@oracle.com>; Juergen Gross > >> <jgr...@suse.com> > >> Subject: RE: [Xen-devel] debian stretch dom0 + xen 4.9 fails to boot > >> > >> >>> On 07.06.17 at 13:55, <paul.durr...@citrix.com> wrote: > >> >> From: Jan Beulich [mailto:jbeul...@suse.com] > >> >> Sent: 07 June 2017 12:50 > >> >> 2) Provide the E820 map of that box. > >> >> I'm suspecting the BIOS might use an EBDA without recording it in > >> >> the low BIOS data area. If it's reported in E820 that would then > >> >> likely be the final kick for us to obey to the E820 map when > >> >> determining where to put the trampoline. > >> >> > >> > > >> > The stretch kernel booted bare-metal reports: > >> > > >> > [ 0.000000] e820: BIOS-provided physical RAM map: > >> > [ 0.000000] BIOS-e820: [mem 0x0000000000000000- > 0x00000000000963ff] > >> usable > >> > [ 0.000000] BIOS-e820: [mem 0x0000000000096400- > 0x000000000009ffff] > >> reserved > >> > >> There we go. Subtracting 4k may then even be too little (depending > >> what EBDA and low memory values the system reports). Of course > >> it would be a BIOS bug if they reported some memory they use for > >> themselves through only E820, as that interface is not required to > >> be present, and really, really old software wouldn't even know > >> about it and would hence also be in trouble. > >> > > > > Neither 4k nor 8k seemed to be enough. Even subtracting another > > 64k doesn't work. > > That's rather unexpected. > > > I guess I'm going to have to try to write some code to log values to > > the VGA buffer to see what is going on. > > Good luck! >
That really was too hard... Instead I reverted the patch and stashed EBDA and the initial location of the trampoline and dumped them in __start_xen(). The EBDA tallies with the E820: (XEN) boot_ebda = 9640 . . (XEN) Xen-e820 RAM map: (XEN) 0000000000000000 - 0000000000096400 (usable) (XEN) 0000000000096400 - 00000000000a0000 (reserved) And the initial location of the trampoline appears to be ok... (XEN) orig_trampoline_phys = 86000 So, still no clue as to why moving the wakeup code around is messing things up. Paul > Jan _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel
