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Add a dedicated flag to track if vmcs02 has been initialized, i.e.
the constant state for vmcs02 has been written to the backing VMCS.
The launched flag (in struct loaded_vmcs) gets cleared on logical
CPU migration to mirror hardware behavior[1], i.e. using the launched
flag to determine whether or not vmcs02 constant state needs to be
initialized results in unnecessarily re-initializing the VMCS when
migrating between logical CPUS.
[1] The active VMCS needs to be VMCLEARed before it can be migrated
to a different logical CPU. Hardware's VMCS cache is per-CPU
and is not coherent between CPUs. VMCLEAR flushes the cache so
that any dirty data is written back to memory. A side effect
of VMCLEAR is that it also clears the VMCS's internal launch
flag, which KVM must mirror because VMRESUME must be used to
run a previously launched VMCS.
Suggested-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
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.
See Documentation/00-INDEX for a list of what is contained in each file.
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.