c82a5c5c53
Do compatibility checks when enabling hardware to effectively add compatibility checks when onlining a CPU. Abort enabling, i.e. the online process, if the (hotplugged) CPU is incompatible with the known good setup. At init time, KVM does compatibility checks to ensure that all online CPUs support hardware virtualization and a common set of features. But KVM uses hotplugged CPUs without such compatibility checks. On Intel CPUs, this leads to #GP if the hotplugged CPU doesn't support VMX, or VM-Entry failure if the hotplugged CPU doesn't support all features enabled by KVM. Note, this is little more than a NOP on SVM, as SVM already checks for full SVM support during hardware enabling. Opportunistically add a pr_err() if setup_vmcs_config() fails, and tweak all error messages to output which CPU failed. Signed-off-by: Chao Gao <chao.gao@intel.com> Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Acked-by: Kai Huang <kai.huang@intel.com> Message-Id: <20221130230934.1014142-41-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.