Paolo Bonzini 1a14928e2e Merge tag 'kvm-x86-misc-6.17' of https://github.com/kvm-x86/linux into HEAD
KVM x86 misc changes for 6.17

 - Prevert the host's DEBUGCTL.FREEZE_IN_SMM (Intel only) when running the
   guest.  Failure to honor FREEZE_IN_SMM can bleed host state into the guest.

 - Explicitly check vmcs12.GUEST_DEBUGCTL on nested VM-Enter (Intel only) to
   prevent L1 from running L2 with features that KVM doesn't support, e.g. BTF.

 - Intercept SPEC_CTRL on AMD if the MSR shouldn't exist according to the
   vCPU's CPUID model.

 - Rework the MSR interception code so that the SVM and VMX APIs are more or
   less identical.

 - Recalculate all MSR intercepts from the "source" on MSR filter changes, and
   drop the dedicated "shadow" bitmaps (and their awful "max" size defines).

 - WARN and reject loading kvm-amd.ko instead of panicking the kernel if the
   nested SVM MSRPM offsets tracker can't handle an MSR.

 - Advertise support for LKGS (Load Kernel GS base), a new instruction that's
   loosely related to FRED, but is supported and enumerated independently.

 - Fix a user-triggerable WARN that syzkaller found by stuffing INIT_RECEIVED,
   a.k.a. WFS, and then putting the vCPU into VMX Root Mode (post-VMXON).  Use
   the same approach KVM uses for dealing with "impossible" emulation when
   running a !URG guest, and simply wait until KVM_RUN to detect that the vCPU
   has architecturally impossible state.

 - Add KVM_X86_DISABLE_EXITS_APERFMPERF to allow disabling interception of
   APERF/MPERF reads, so that a "properly" configured VM can "virtualize"
   APERF/MPERF (with many caveats).

 - Reject KVM_SET_TSC_KHZ if vCPUs have been created, as changing the "default"
   frequency is unsupported for VMs with a "secure" TSC, and there's no known
   use case for changing the default frequency for other VM types.
2025-07-29 08:36:43 -04:00
2022-09-28 09:02:20 +02:00
2025-07-19 19:26:16 -07:00
2025-02-19 14:53:27 -07:00
2025-07-27 14:26:38 -07:00
2024-03-18 03:36:32 -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 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.
Description
No description provided
Readme 3.4 GiB
Languages
C 97%
Assembly 1%
Shell 0.6%
Rust 0.5%
Python 0.4%
Other 0.3%