511a8556e3
MSR IA32_MISC_ENABLE bit 18, according to SDM: | When this bit is set to 0, the MONITOR feature flag is not set (CPUID.01H:ECX[bit 3] = 0). | This indicates that MONITOR/MWAIT are not supported. | | Software attempts to execute MONITOR/MWAIT will cause #UD when this bit is 0. | | When this bit is set to 1 (default), MONITOR/MWAIT are supported (CPUID.01H:ECX[bit 3] = 1). The CPUID.01H:ECX[bit 3] ought to mirror the value of the MSR bit, CPUID.01H:ECX[bit 3] is a better guard than kvm_mwait_in_guest(). kvm_mwait_in_guest() affects the behavior of MONITOR/MWAIT, not its guest visibility. This patch implements toggling of the CPUID bit based on guest writes to the MSR. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Sean Christopherson <sean.j.christopherson@intel.com> Cc: Liran Alon <liran.alon@oracle.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Wanpeng Li <wanpengli@tencent.com> [Fixes for backwards compatibility - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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.