[GIT PULL] x86 fixes

Ingo Molnar
2025-04-10T21:25:56Z

Linus,

Please pull the latest x86/urgent Git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86-urgent-2025-04-10

# HEAD: 1fac13956e9877483ece9d090a62239cdfe9deb7 x86/ibt: Fix hibernate

Merge note:

The RSB fix series includes updates that are technically not
regression fixes, but updates to match the code to CPU vendor best
recommended practices, add documentation, etc. Given that we are
still finding bugs in this code I found it prudent to not fork the
code for v6.16 right after -rc1, but have the entire series in v6.15.
If this is too much for -rc2, will rebase and resend.

Miscellaneous fixes:

- Fix CPU topology related regression that limited
Xen PV guests to a single CPU

- Fix ancient e820__register_nosave_regions() bugs that
were causing problems with kexec's artificial memory
maps

- Fix an S4 hibernation crash caused by two missing ENDBR's that
were mistakenly removed in a recent commit

- Fix a resctrl serialization bug

- Fix early_printk documentation and comments

- Fix RSB bugs, combined with preparatory updates to better
match the code to vendor recommendations.

- Add RSB mitigation document

- Fix/update documentation

- Fix the erratum_1386_microcode[] table to be NULL terminated

Thanks,

Ingo

------------------>
Andy Shevchenko (1):
x86/early_printk: Use 'mmio32' for consistency, fix comments

Borislav Petkov (AMD) (1):
Documentation/x86: Zap the subsection letters

Dave Hansen (1):
x86/cpu: Avoid running off the end of an AMD erratum table

James Morse (1):
x86/resctrl: Fix rdtgroup_mkdir()'s unlocked use of kernfs_node::name

Josh Poimboeuf (6):
x86/bugs: Rename entry_ibpb() to write_ibpb()
x86/bugs: Use SBPB in write_ibpb() if applicable
x86/bugs: Fix RSB clearing in indirect_branch_prediction_barrier()
x86/bugs: Don't fill RSB on VMEXIT with eIBRS+retpoline
x86/bugs: Don't fill RSB on context switch with eIBRS
x86/bugs: Add RSB mitigation document

Myrrh Periwinkle (1):
x86/e820: Fix handling of subpage regions when calculating nosave ranges in e820__register_nosave_regions()

Naveen N Rao (AMD) (1):
Documentation/x86: Update the naming of CPU features for /proc/cpuinfo

Peter Zijlstra (1):
x86/ibt: Fix hibernate

Petr Vaněk (1):
x86/acpi: Don't limit CPUs to 1 for Xen PV guests due to disabled ACPI

Documentation/admin-guide/hw-vuln/index.rst | 1 +
Documentation/admin-guide/hw-vuln/rsb.rst | 268 ++++++++++++++++++++++++
Documentation/admin-guide/kernel-parameters.txt | 5 +-
Documentation/arch/x86/cpuinfo.rst | 69 +++---
arch/x86/entry/entry.S | 9 +-
arch/x86/include/asm/nospec-branch.h | 12 +-
arch/x86/kernel/acpi/boot.c | 11 +
arch/x86/kernel/cpu/amd.c | 1 +
arch/x86/kernel/cpu/bugs.c | 101 +++------
arch/x86/kernel/cpu/resctrl/rdtgroup.c | 48 +++--
arch/x86/kernel/e820.c | 17 +-
arch/x86/kernel/early_printk.c | 10 +-
arch/x86/mm/tlb.c | 6 +-
arch/x86/power/hibernate_asm_64.S | 4 +-
14 files changed, 405 insertions(+), 157 deletions(-)
create mode 100644 Documentation/admin-guide/hw-vuln/rsb.rst