mirror of
https://github.com/hardkernel/linux.git
synced 2026-06-03 09:41:54 +09:00
b26a71a1a5
Refuse to load KVM if NX support is not available. Shadow paging has assumed NX support since commit9167ab7993("KVM: vmx, svm: always run with EFER.NXE=1 when shadow paging is active"), and NPT has assumed NX support since commitb8e8c8303f("kvm: mmu: ITLB_MULTIHIT mitigation"). While the NX huge pages mitigation should not be enabled by default for AMD CPUs, it can be turned on by userspace at will. Unlike Intel CPUs, AMD does not provide a way for firmware to disable NX support, and Linux always sets EFER.NX=1 if it is supported. Given that it's extremely unlikely that a CPU supports NPT but not NX, making NX a formal requirement is far simpler than adding requirements to the mitigation flow. Fixes:9167ab7993("KVM: vmx, svm: always run with EFER.NXE=1 when shadow paging is active") Fixes:b8e8c8303f("kvm: mmu: ITLB_MULTIHIT mitigation") Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Jim Mattson <jmattson@google.com> Message-Id: <20210615164535.2146172-3-seanjc@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.
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.