mirror of
https://github.com/hardkernel/linux.git
synced 2026-06-05 18:41:58 +09:00
fa4c027a79
Add support for SVM's Virtual NMIs implementation, which adds proper tracking of virtual NMI blocking, and an intr_ctrl flag that software can set to mark a virtual NMI as pending. Pending virtual NMIs are serviced by hardware if/when virtual NMIs become unblocked, i.e. act more or less like real NMIs. Introduce two new kvm_x86_ops callbacks so to support SVM's vNMI, as KVM needs to treat a pending vNMI as partially injected. Specifically, if two NMIs (for L1) arrive concurrently in KVM's software model, KVM's ABI is to inject one and pend the other. Without vNMI, KVM manually tracks the pending NMI and uses NMI windows to detect when the NMI should be injected. With vNMI, the pending NMI is simply stuffed into the VMCB and handed off to hardware. This means that KVM needs to be able to set a vNMI pending on-demand, and also query if a vNMI is pending, e.g. to honor the "at most one NMI pending" rule and to preserve all NMIs across save and restore. Warn if KVM attempts to open an NMI window when vNMI is fully enabled, as the above logic should prevent KVM from ever getting to kvm_check_and_inject_events() with two NMIs pending _in software_, and the "at most one NMI pending" logic should prevent having an NMI pending in hardware and an NMI pending in software if NMIs are also blocked, i.e. if KVM can't immediately inject the second NMI. Signed-off-by: Santosh Shukla <Santosh.Shukla@amd.com> Co-developed-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Link: https://lore.kernel.org/r/20230227084016.3368-11-santosh.shukla@amd.com [sean: rewrite shortlog and changelog, massage code comments] Signed-off-by: Sean Christopherson <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 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.