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68e51d0a43
Add an off-by-default module param to control whether or not KVM is allowed to map memory that isn't pinned, i.e. that KVM can't guarantee won't be freed while it is mapped into KVM and/or the guest. Don't remove the functionality entirely, as there are use cases where mapping unpinned memory is safe (as defined by the platform owner), e.g. when memory is hidden from the kernel and managed by userspace, in which case userspace is already fully trusted to not muck with guest memory mappings. But for more typical setups, mapping unpinned memory is wildly unsafe, and unnecessary. The APIs are used exclusively by x86's nested virtualization support, and there is no known (or sane) use case for mapping PFN-mapped memory a KVM guest _and_ letting the guest use it for virtualization structures. Tested-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Sean Christopherson <seanjc@google.com> Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-ID: <20241010182427.1434605-36-seanjc@google.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 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.