Besides a printk() the main effect is slight corruption of the start
info magic: While that's meant to be xen-3.0-x86_64, it wrongly ended
up as xen-3.0-x86_64p.
Note that no known users exist that would have developed a dependency on
the bogus magic string. In particular Linux, NetBSD, and mini-os have
been checked.
Fixes: 460060f83d41 ("libelf: use for x86 dom0 builder")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
---
RFC: While Linux works fine with the adjustment, I'm not entirely
certain of external tools (crash?) having grown a dependency. It
may be worth noting that XenoLinux and its forward ports never had
this ELF note in 64-bit kernels, so in principle it may be
reasonable to expect that no such dependency exists anywhere.
Prior to "x86/PV32: restore PAE-extended-CR3 logic" that (meaningless
for 64-bit domains) VM-assist could also be engaged, based on the ELF
note's value. I expect that change to go in first, at which point the
description here is going to be correct (in not mentioning this VM-
assist aspect).
---
v2: Extend description.
--- a/xen/arch/x86/pv/dom0_build.c
+++ b/xen/arch/x86/pv/dom0_build.c
@@ -459,8 +459,13 @@ int __init dom0_construct_pv(struct doma
compat = is_pv_32bit_domain(d);
if ( elf_64bit(&elf) && machine == EM_X86_64 )
+ {
compatible = true;
+ /* Zap meaningless setting which kernels may carry by mistake. */
+ parms.pae = 0;
+ }
+
if ( elf_msb(&elf) )
compatible = false;
On 04/04/2023 10:19 am, Jan Beulich wrote: > Besides a printk() the main effect is slight corruption of the start > info magic: While that's meant to be xen-3.0-x86_64, it wrongly ended > up as xen-3.0-x86_64p. > > Note that no known users exist that would have developed a dependency on > the bogus magic string. In particular Linux, NetBSD, and mini-os have > been checked. > > Fixes: 460060f83d41 ("libelf: use for x86 dom0 builder") > Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
On Tue, Apr 04, 2023 at 11:19:08AM +0200, Jan Beulich wrote: > Besides a printk() the main effect is slight corruption of the start > info magic: While that's meant to be xen-3.0-x86_64, it wrongly ended > up as xen-3.0-x86_64p. > > Note that no known users exist that would have developed a dependency on > the bogus magic string. In particular Linux, NetBSD, and mini-os have > been checked. > > Fixes: 460060f83d41 ("libelf: use for x86 dom0 builder") > Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Roger Pau Monné <roger.pau@citrix.com> > --- > RFC: While Linux works fine with the adjustment, I'm not entirely > certain of external tools (crash?) having grown a dependency. It > may be worth noting that XenoLinux and its forward ports never had > this ELF note in 64-bit kernels, so in principle it may be > reasonable to expect that no such dependency exists anywhere. > > Prior to "x86/PV32: restore PAE-extended-CR3 logic" that (meaningless > for 64-bit domains) VM-assist could also be engaged, based on the ELF > note's value. I expect that change to go in first, at which point the > description here is going to be correct (in not mentioning this VM- > assist aspect). Will look at it now. Thanks, Roger.
© 2016 - 2024 Red Hat, Inc.