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Linus Torvalds 6803bd7956 ARM:
* Generalized infrastructure for 'writable' ID registers, effectively
   allowing userspace to opt-out of certain vCPU features for its guest
 
 * Optimization for vSGI injection, opportunistically compressing MPIDR
   to vCPU mapping into a table
 
 * Improvements to KVM's PMU emulation, allowing userspace to select
   the number of PMCs available to a VM
 
 * Guest support for memory operation instructions (FEAT_MOPS)
 
 * Cleanups to handling feature flags in KVM_ARM_VCPU_INIT, squashing
   bugs and getting rid of useless code
 
 * Changes to the way the SMCCC filter is constructed, avoiding wasted
   memory allocations when not in use
 
 * Load the stage-2 MMU context at vcpu_load() for VHE systems, reducing
   the overhead of errata mitigations
 
 * Miscellaneous kernel and selftest fixes
 
 LoongArch:
 
 * New architecture.  The hardware uses the same model as x86, s390
   and RISC-V, where guest/host mode is orthogonal to supervisor/user
   mode.  The virtualization extensions are very similar to MIPS,
   therefore the code also has some similarities but it's been cleaned
   up to avoid some of the historical bogosities that are found in
   arch/mips.  The kernel emulates MMU, timer and CSR accesses, while
   interrupt controllers are only emulated in userspace, at least for
   now.
 
 RISC-V:
 
 * Support for the Smstateen and Zicond extensions
 
 * Support for virtualizing senvcfg
 
 * Support for virtualized SBI debug console (DBCN)
 
 S390:
 
 * Nested page table management can be monitored through tracepoints
   and statistics
 
 x86:
 
 * Fix incorrect handling of VMX posted interrupt descriptor in KVM_SET_LAPIC,
   which could result in a dropped timer IRQ
 
 * Avoid WARN on systems with Intel IPI virtualization
 
 * Add CONFIG_KVM_MAX_NR_VCPUS, to allow supporting up to 4096 vCPUs without
   forcing more common use cases to eat the extra memory overhead.
 
 * Add virtualization support for AMD SRSO mitigation (IBPB_BRTYPE and
   SBPB, aka Selective Branch Predictor Barrier).
 
 * Fix a bug where restoring a vCPU snapshot that was taken within 1 second of
   creating the original vCPU would cause KVM to try to synchronize the vCPU's
   TSC and thus clobber the correct TSC being set by userspace.
 
 * Compute guest wall clock using a single TSC read to avoid generating an
   inaccurate time, e.g. if the vCPU is preempted between multiple TSC reads.
 
 * "Virtualize" HWCR.TscFreqSel to make Linux guests happy, which complain
   about a "Firmware Bug" if the bit isn't set for select F/M/S combos.
   Likewise "virtualize" (ignore) MSR_AMD64_TW_CFG to appease Windows Server
   2022.
 
 * Don't apply side effects to Hyper-V's synthetic timer on writes from
   userspace to fix an issue where the auto-enable behavior can trigger
   spurious interrupts, i.e. do auto-enabling only for guest writes.
 
 * Remove an unnecessary kick of all vCPUs when synchronizing the dirty log
   without PML enabled.
 
 * Advertise "support" for non-serializing FS/GS base MSR writes as appropriate.
 
 * Harden the fast page fault path to guard against encountering an invalid
   root when walking SPTEs.
 
 * Omit "struct kvm_vcpu_xen" entirely when CONFIG_KVM_XEN=n.
 
 * Use the fast path directly from the timer callback when delivering Xen
   timer events, instead of waiting for the next iteration of the run loop.
   This was not done so far because previously proposed code had races,
   but now care is taken to stop the hrtimer at critical points such as
   restarting the timer or saving the timer information for userspace.
 
 * Follow the lead of upstream Xen and ignore the VCPU_SSHOTTMR_future flag.
 
 * Optimize injection of PMU interrupts that are simultaneous with NMIs.
 
 * Usual handful of fixes for typos and other warts.
 
 x86 - MTRR/PAT fixes and optimizations:
 
 * Clean up code that deals with honoring guest MTRRs when the VM has
   non-coherent DMA and host MTRRs are ignored, i.e. EPT is enabled.
 
 * Zap EPT entries when non-coherent DMA assignment stops/start to prevent
   using stale entries with the wrong memtype.
 
 * Don't ignore guest PAT for CR0.CD=1 && KVM_X86_QUIRK_CD_NW_CLEARED=y.
   This was done as a workaround for virtual machine BIOSes that did not
   bother to clear CR0.CD (because ancient KVM/QEMU did not bother to
   set it, in turn), and there's zero reason to extend the quirk to
   also ignore guest PAT.
 
 x86 - SEV fixes:
 
 * Report KVM_EXIT_SHUTDOWN instead of EINVAL if KVM intercepts SHUTDOWN while
   running an SEV-ES guest.
 
 * Clean up the recognition of emulation failures on SEV guests, when KVM would
   like to "skip" the instruction but it had already been partially emulated.
   This makes it possible to drop a hack that second guessed the (insufficient)
   information provided by the emulator, and just do the right thing.
 
 Documentation:
 
 * Various updates and fixes, mostly for x86
 
 * MTRR and PAT fixes and optimizations:
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm updates from Paolo Bonzini:
 "ARM:

   - Generalized infrastructure for 'writable' ID registers, effectively
     allowing userspace to opt-out of certain vCPU features for its
     guest

   - Optimization for vSGI injection, opportunistically compressing
     MPIDR to vCPU mapping into a table

   - Improvements to KVM's PMU emulation, allowing userspace to select
     the number of PMCs available to a VM

   - Guest support for memory operation instructions (FEAT_MOPS)

   - Cleanups to handling feature flags in KVM_ARM_VCPU_INIT, squashing
     bugs and getting rid of useless code

   - Changes to the way the SMCCC filter is constructed, avoiding wasted
     memory allocations when not in use

   - Load the stage-2 MMU context at vcpu_load() for VHE systems,
     reducing the overhead of errata mitigations

   - Miscellaneous kernel and selftest fixes

  LoongArch:

   - New architecture for kvm.

     The hardware uses the same model as x86, s390 and RISC-V, where
     guest/host mode is orthogonal to supervisor/user mode. The
     virtualization extensions are very similar to MIPS, therefore the
     code also has some similarities but it's been cleaned up to avoid
     some of the historical bogosities that are found in arch/mips. The
     kernel emulates MMU, timer and CSR accesses, while interrupt
     controllers are only emulated in userspace, at least for now.

  RISC-V:

   - Support for the Smstateen and Zicond extensions

   - Support for virtualizing senvcfg

   - Support for virtualized SBI debug console (DBCN)

  S390:

   - Nested page table management can be monitored through tracepoints
     and statistics

  x86:

   - Fix incorrect handling of VMX posted interrupt descriptor in
     KVM_SET_LAPIC, which could result in a dropped timer IRQ

   - Avoid WARN on systems with Intel IPI virtualization

   - Add CONFIG_KVM_MAX_NR_VCPUS, to allow supporting up to 4096 vCPUs
     without forcing more common use cases to eat the extra memory
     overhead.

   - Add virtualization support for AMD SRSO mitigation (IBPB_BRTYPE and
     SBPB, aka Selective Branch Predictor Barrier).

   - Fix a bug where restoring a vCPU snapshot that was taken within 1
     second of creating the original vCPU would cause KVM to try to
     synchronize the vCPU's TSC and thus clobber the correct TSC being
     set by userspace.

   - Compute guest wall clock using a single TSC read to avoid
     generating an inaccurate time, e.g. if the vCPU is preempted
     between multiple TSC reads.

   - "Virtualize" HWCR.TscFreqSel to make Linux guests happy, which
     complain about a "Firmware Bug" if the bit isn't set for select
     F/M/S combos. Likewise "virtualize" (ignore) MSR_AMD64_TW_CFG to
     appease Windows Server 2022.

   - Don't apply side effects to Hyper-V's synthetic timer on writes
     from userspace to fix an issue where the auto-enable behavior can
     trigger spurious interrupts, i.e. do auto-enabling only for guest
     writes.

   - Remove an unnecessary kick of all vCPUs when synchronizing the
     dirty log without PML enabled.

   - Advertise "support" for non-serializing FS/GS base MSR writes as
     appropriate.

   - Harden the fast page fault path to guard against encountering an
     invalid root when walking SPTEs.

   - Omit "struct kvm_vcpu_xen" entirely when CONFIG_KVM_XEN=n.

   - Use the fast path directly from the timer callback when delivering
     Xen timer events, instead of waiting for the next iteration of the
     run loop. This was not done so far because previously proposed code
     had races, but now care is taken to stop the hrtimer at critical
     points such as restarting the timer or saving the timer information
     for userspace.

   - Follow the lead of upstream Xen and ignore the VCPU_SSHOTTMR_future
     flag.

   - Optimize injection of PMU interrupts that are simultaneous with
     NMIs.

   - Usual handful of fixes for typos and other warts.

  x86 - MTRR/PAT fixes and optimizations:

   - Clean up code that deals with honoring guest MTRRs when the VM has
     non-coherent DMA and host MTRRs are ignored, i.e. EPT is enabled.

   - Zap EPT entries when non-coherent DMA assignment stops/start to
     prevent using stale entries with the wrong memtype.

   - Don't ignore guest PAT for CR0.CD=1 && KVM_X86_QUIRK_CD_NW_CLEARED=y

     This was done as a workaround for virtual machine BIOSes that did
     not bother to clear CR0.CD (because ancient KVM/QEMU did not bother
     to set it, in turn), and there's zero reason to extend the quirk to
     also ignore guest PAT.

  x86 - SEV fixes:

   - Report KVM_EXIT_SHUTDOWN instead of EINVAL if KVM intercepts
     SHUTDOWN while running an SEV-ES guest.

   - Clean up the recognition of emulation failures on SEV guests, when
     KVM would like to "skip" the instruction but it had already been
     partially emulated. This makes it possible to drop a hack that
     second guessed the (insufficient) information provided by the
     emulator, and just do the right thing.

  Documentation:

   - Various updates and fixes, mostly for x86

   - MTRR and PAT fixes and optimizations"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (164 commits)
  KVM: selftests: Avoid using forced target for generating arm64 headers
  tools headers arm64: Fix references to top srcdir in Makefile
  KVM: arm64: Add tracepoint for MMIO accesses where ISV==0
  KVM: arm64: selftest: Perform ISB before reading PAR_EL1
  KVM: arm64: selftest: Add the missing .guest_prepare()
  KVM: arm64: Always invalidate TLB for stage-2 permission faults
  KVM: x86: Service NMI requests after PMI requests in VM-Enter path
  KVM: arm64: Handle AArch32 SPSR_{irq,abt,und,fiq} as RAZ/WI
  KVM: arm64: Do not let a L1 hypervisor access the *32_EL2 sysregs
  KVM: arm64: Refine _EL2 system register list that require trap reinjection
  arm64: Add missing _EL2 encodings
  arm64: Add missing _EL12 encodings
  KVM: selftests: aarch64: vPMU test for validating user accesses
  KVM: selftests: aarch64: vPMU register test for unimplemented counters
  KVM: selftests: aarch64: vPMU register test for implemented counters
  KVM: selftests: aarch64: Introduce vpmu_counter_access test
  tools: Import arm_pmuv3.h
  KVM: arm64: PMU: Allow userspace to limit PMCR_EL0.N for the guest
  KVM: arm64: Sanitize PM{C,I}NTEN{SET,CLR}, PMOVS{SET,CLR} before first run
  KVM: arm64: Add {get,set}_user for PM{C,I}NTEN{SET,CLR}, PMOVS{SET,CLR}
  ...
2023-11-02 15:45:15 -10:00
arch ARM: 2023-11-02 15:45:15 -10:00
block for-6.7/block-2023-10-30 2023-11-01 12:30:07 -10:00
certs certs: Only allow certs signed by keys on the builtin keyring 2023-10-31 08:22:36 -04:00
crypto integrity-v6.7 2023-11-02 06:53:22 -10:00
Documentation ARM: 2023-11-02 15:45:15 -10:00
drivers sh updates for v6.7 2023-11-02 15:34:59 -10:00
fs 7 ksmbd server fixes 2023-11-02 08:32:07 -10:00
include ARM: 2023-11-02 15:45:15 -10:00
init sysctl-6.7-rc1 2023-11-01 20:51:41 -10:00
io_uring io_uring-futex-2023-10-30 2023-11-01 11:25:08 -10:00
ipc ipc: convert to new timestamp accessors 2023-10-18 14:08:30 +02:00
kernel - Core Frameworks 2023-11-02 14:40:51 -10:00
lib linux_kselftest-kunit-6.7-rc1 2023-11-01 17:02:29 -10:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm asm-generic updates for v6.7 2023-11-01 15:28:33 -10:00
net Follow up to networking PR for 6.7 2023-11-01 16:33:20 -10:00
rust workqueue: Add rust bindings for v6.7 2023-10-30 20:35:48 -10:00
samples Probes updates for v6.7: 2023-11-01 16:15:42 -10:00
scripts Modules changes for v6.7-rc1 2023-11-01 21:09:37 -10:00
security integrity-v6.7 2023-11-02 06:53:22 -10:00
sound sound updates for 6.7 2023-11-02 14:34:14 -10:00
tools ARM: 2023-11-02 15:45:15 -10:00
usr arch: Remove Itanium (IA-64) architecture 2023-09-11 08:13:17 +00:00
virt ARM: 2023-09-07 13:52:20 -07:00
.clang-format iommu: Add for_each_group_device() 2023-05-23 08:15:51 +02:00
.cocciconfig
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: rpm-pkg: rename binkernel.spec to kernel.spec 2023-07-25 00:59:33 +09:00
.mailmap 20 hotfixes. 12 are cc:stable and the remainder address post-6.5 issues 2023-10-24 09:52:16 -10:00
.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 USB: Remove Wireless USB and UWB documentation 2023-08-09 14:17:32 +02:00
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 ARM: 2023-11-02 15:45:15 -10:00
Makefile linux_kselftest-next-6.7-rc1 2023-11-01 17:08:10 -10:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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 Restructured Text 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.