This patch set adds support for the Intel flexible return and event delivery (FRED) architecture to allow Qemu to run KVM guests with FRED enabled. The FRED architecture defines simple new transitions that change privilege level (ring transitions). The FRED architecture was designed with the following goals: 1) Improve overall performance and response time by replacing event delivery through the interrupt descriptor table (IDT event delivery) and event return by the IRET instruction with lower latency transitions. 2) Improve software robustness by ensuring that event delivery establishes the full supervisor context and that event return establishes the full user context. Search for the latest FRED spec in most search engines with this search pattern: site:intel.com FRED (flexible return and event delivery) specification --- Changelog v2: - Add VMX nested-exception support to scripts/kvm/vmxcap (Paolo Bonzini). - Move FRED MSRs from basic x86_cpu part to .subsections part (Weijiang Yang). Xin Li (4): target/i386: add support for FRED in CPUID enumeration target/i386: mark CR4.FRED not reserved target/i386: enumerate VMX nested-exception support target/i386: Add get/set/migrate support for FRED MSRs scripts/kvm/vmxcap | 1 + target/i386/cpu.c | 7 +++++- target/i386/cpu.h | 43 +++++++++++++++++++++++++++++++++- target/i386/kvm/kvm.c | 54 +++++++++++++++++++++++++++++++++++++++++++ target/i386/machine.c | 29 +++++++++++++++++++++++ 5 files changed, 132 insertions(+), 2 deletions(-) -- 2.34.1
