Go to file
Linus Torvalds 817772266d * Clean up SVM's enter/exit assembly code so that it can be compiled
without OBJECT_FILES_NON_STANDARD.  This fixes a warning
   "Unpatched return thunk in use. This should not happen!" when running
   KVM selftests.
 
 * Fix a mostly benign bug in the gfn_to_pfn_cache infrastructure where KVM
   would allow userspace to refresh the cache with a bogus GPA.  The bug has
   existed for quite some time, but was exposed by a new sanity check added in
   6.9 (to ensure a cache is either GPA-based or HVA-based).
 
 * Drop an unused param from gfn_to_pfn_cache_invalidate_start() that got left
   behind during a 6.9 cleanup.
 
 * Fix a math goof in x86's hugepage logic for KVM_SET_MEMORY_ATTRIBUTES that
   results in an array overflow (detected by KASAN).
 
 * Fix a bug where KVM incorrectly clears root_role.direct when userspace sets
   guest CPUID.
 
 * Fix a dirty logging bug in the where KVM fails to write-protect SPTEs used
   by a nested guest, if KVM is using Page-Modification Logging and the nested
   hypervisor is NOT using EPT.
 
 x86 PMU:
 
 * Drop support for virtualizing adaptive PEBS, as KVM's implementation is
   architecturally broken without an obvious/easy path forward, and because
   exposing adaptive PEBS can leak host LBRs to the guest, i.e. can leak
   host kernel addresses to the guest.
 
 * Set the enable bits for general purpose counters in PERF_GLOBAL_CTRL at
   RESET time, as done by both Intel and AMD processors.
 
 * Disable LBR virtualization on CPUs that don't support LBR callstacks, as
   KVM unconditionally uses PERF_SAMPLE_BRANCH_CALL_STACK when creating the
   perf event, and would fail on such CPUs.
 
 Tests:
 
 * Fix a flaw in the max_guest_memory selftest that results in it exhausting
   the supply of ucall structures when run with more than 256 vCPUs.
 
 * Mark KVM_MEM_READONLY as supported for RISC-V in set_memory_region_test.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm fixes from Paolo Bonzini:
 "This is a bit on the large side, mostly due to two changes:

   - Changes to disable some broken PMU virtualization (see below for
     details under "x86 PMU")

   - Clean up SVM's enter/exit assembly code so that it can be compiled
     without OBJECT_FILES_NON_STANDARD. This fixes a warning "Unpatched
     return thunk in use. This should not happen!" when running KVM
     selftests.

  Everything else is small bugfixes and selftest changes:

   - Fix a mostly benign bug in the gfn_to_pfn_cache infrastructure
     where KVM would allow userspace to refresh the cache with a bogus
     GPA. The bug has existed for quite some time, but was exposed by a
     new sanity check added in 6.9 (to ensure a cache is either
     GPA-based or HVA-based).

   - Drop an unused param from gfn_to_pfn_cache_invalidate_start() that
     got left behind during a 6.9 cleanup.

   - Fix a math goof in x86's hugepage logic for
     KVM_SET_MEMORY_ATTRIBUTES that results in an array overflow
     (detected by KASAN).

   - Fix a bug where KVM incorrectly clears root_role.direct when
     userspace sets guest CPUID.

   - Fix a dirty logging bug in the where KVM fails to write-protect
     SPTEs used by a nested guest, if KVM is using Page-Modification
     Logging and the nested hypervisor is NOT using EPT.

  x86 PMU:

   - Drop support for virtualizing adaptive PEBS, as KVM's
     implementation is architecturally broken without an obvious/easy
     path forward, and because exposing adaptive PEBS can leak host LBRs
     to the guest, i.e. can leak host kernel addresses to the guest.

   - Set the enable bits for general purpose counters in
     PERF_GLOBAL_CTRL at RESET time, as done by both Intel and AMD
     processors.

   - Disable LBR virtualization on CPUs that don't support LBR
     callstacks, as KVM unconditionally uses
     PERF_SAMPLE_BRANCH_CALL_STACK when creating the perf event, and
     would fail on such CPUs.

  Tests:

   - Fix a flaw in the max_guest_memory selftest that results in it
     exhausting the supply of ucall structures when run with more than
     256 vCPUs.

   - Mark KVM_MEM_READONLY as supported for RISC-V in
     set_memory_region_test"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (30 commits)
  KVM: Drop unused @may_block param from gfn_to_pfn_cache_invalidate_start()
  KVM: selftests: Add coverage of EPT-disabled to vmx_dirty_log_test
  KVM: x86/mmu: Fix and clarify comments about clearing D-bit vs. write-protecting
  KVM: x86/mmu: Remove function comments above clear_dirty_{gfn_range,pt_masked}()
  KVM: x86/mmu: Write-protect L2 SPTEs in TDP MMU when clearing dirty status
  KVM: x86/mmu: Precisely invalidate MMU root_role during CPUID update
  KVM: VMX: Disable LBR virtualization if the CPU doesn't support LBR callstacks
  perf/x86/intel: Expose existence of callback support to KVM
  KVM: VMX: Snapshot LBR capabilities during module initialization
  KVM: x86/pmu: Do not mask LVTPC when handling a PMI on AMD platforms
  KVM: x86: Snapshot if a vCPU's vendor model is AMD vs. Intel compatible
  KVM: x86: Stop compiling vmenter.S with OBJECT_FILES_NON_STANDARD
  KVM: SVM: Create a stack frame in __svm_sev_es_vcpu_run()
  KVM: SVM: Save/restore args across SEV-ES VMRUN via host save area
  KVM: SVM: Save/restore non-volatile GPRs in SEV-ES VMRUN via host save area
  KVM: SVM: Clobber RAX instead of RBX when discarding spec_ctrl_intercepted
  KVM: SVM: Drop 32-bit "support" from __svm_sev_es_vcpu_run()
  KVM: SVM: Wrap __svm_sev_es_vcpu_run() with #ifdef CONFIG_KVM_AMD_SEV
  KVM: SVM: Create a stack frame in __svm_vcpu_run() for unwinding
  KVM: SVM: Remove a useless zeroing of allocated memory
  ...
2024-04-20 11:10:51 -07:00
Documentation 15 hotfixes. 9 are cc:stable and the remainder address post-6.8 issues 2024-04-19 09:13:35 -07:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
arch * Clean up SVM's enter/exit assembly code so that it can be compiled 2024-04-20 11:10:51 -07:00
block block-6.9-20240412 2024-04-12 10:22:33 -07:00
certs This update includes the following changes: 2023-11-02 16:15:30 -10:00
crypto This push fixes a regression that broke iwd as well as a divide by 2024-03-25 10:48:23 -07:00
drivers A couple clk driver fixes, a build fix, and a deadlock fix. 2024-04-20 10:36:02 -07:00
fs fs/9p: fixes regressions in 6.9 2024-04-19 13:36:28 -07:00
include A couple clk driver fixes, a build fix, and a deadlock fix. 2024-04-20 10:36:02 -07:00
init init/main.c: Fix potential static_command_line memory overflow 2024-04-13 00:59:36 +09:00
io_uring io_uring/net: restore msg_control on sendzc retry 2024-04-08 21:48:41 -06:00
ipc sysctl changes for v6.9-rc1 2024-03-18 14:59:13 -07:00
kernel hardening fixes for v6.9-rc5 2024-04-19 14:10:11 -07:00
lib hardening fixes for v6.9-rc5 2024-04-19 14:10:11 -07:00
mm mm/shmem: inline shmem_is_huge() for disabled transparent hugepages 2024-04-16 15:39:51 -07:00
net netfilter pull request 24-04-18 2024-04-18 13:12:37 +02:00
rust Kbuild updates for v6.9 2024-03-21 14:41:00 -07:00
samples Tracing updates for 6.9: 2024-03-18 15:11:44 -07:00
scripts hardening fixes for v6.9-rc4 2024-04-10 13:31:34 -07:00
security security: Place security_path_post_mknod() where the original IMA call was 2024-04-03 10:21:32 -07:00
sound ALSA: seq: ump: Fix conversion from MIDI2 to MIDI1 UMP messages 2024-04-19 12:07:14 +02:00
tools * Clean up SVM's enter/exit assembly code so that it can be compiled 2024-04-20 11:10:51 -07:00
usr Kbuild updates for v6.8 2024-01-18 17:57:07 -08:00
virt KVM: Drop unused @may_block param from gfn_to_pfn_cache_invalidate_start() 2024-04-11 12:58:53 -07:00
.clang-format clang-format: Update with v6.7-rc4's `for_each` macro list 2023-12-08 23:54:38 +01:00
.cocciconfig
.editorconfig Add .editorconfig file for basic formatting 2023-12-28 16:22:47 +09:00
.get_maintainer.ignore Add Jeff Kirsher to .get_maintainer.ignore 2024-03-08 11:36:54 +00:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: create a list of all built DTB files 2024-02-19 18:20:39 +09:00
.mailmap MAINTAINERS: update Naoya Horiguchi's email address 2024-04-16 15:39:51 -07:00
.rustfmt.toml rust: add `.rustfmt.toml` 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Drop Gustavo Pimentel as PCI DWC Maintainer 2024-03-27 13:41:02 -05:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS MAINTAINERS: update Naoya Horiguchi's email address 2024-04-16 15:39:51 -07:00
Makefile Linux 6.9-rc4 2024-04-14 13:38:39 -07:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.