mainlining shenanigans
4a204f7895
Expand KVM's mask for the AVIC host physical ID to the full 12 bits defined
by the architecture. The number of bits consumed by hardware is model
specific, e.g. early CPUs ignored bits 11:8, but there is no way for KVM
to enumerate the "true" size. So, KVM must allow using all bits, else it
risks rejecting completely legal x2APIC IDs on newer CPUs.
This means KVM relies on hardware to not assign x2APIC IDs that exceed the
"true" width of the field, but presumably hardware is smart enough to tie
the width to the max x2APIC ID. KVM also relies on hardware to support at
least 8 bits, as the legacy xAPIC ID is writable by software. But, those
assumptions are unavoidable due to the lack of any way to enumerate the
"true" width.
Cc: stable@vger.kernel.org
Cc: Maxim Levitsky <mlevitsk@redhat.com>
Suggested-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Fixes:
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||
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| 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 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.