This series aims to add the virtualization of split lock detection for guest, while containing some fixes of native kernel split lock handling. Note, this series is based on the kernel patch[1]. Patch 1 is the fix and enhancement for kernel split lock detction. It ensures X86_FEATURE_SPLIT_LOCK_DETECT flag is set after verifying the feature is really supported. And it explicitly turn off split lock when sld_off instead of assuming BIOS/firmware leaves it cleared. Patch 2 optimizes the runtime MSR accessing. Patch 3-4 are the preparation for enabling split lock detection virtualization in KVM. Patch 5 fixes the issue tht malicious guest may exploit kvm emulator to attcact host kernel. Patch 6 handles guest's split lock when host truns split lock detect on. Patch 7-9 implement the virtualization of split lock detection in kvm. [1]: https://lore.kernel.org/lkml/158031147976.396.8941798847364718785.tip-bot2@tip-bot2/ v5: - Use X86_FEATURE_SPLIT_LOCK_DETECT flag in kvm to ensure split lock detection is really supported. - Add and export sld related helper functions in their related usecase kvm patches. v4: - Add patch 1 to rework the initialization flow of split lock detection. - Drop percpu MSR_TEST_CTRL cache, just use a static variable to cache the reserved/unused bit of MSR_TEST_CTRL. [Sean] - Add new option for split_lock_detect kernel param. - Changlog refinement. [Sean] - Add a new patch to enable MSR_TEST_CTRL for intel guest. [Sean] Xiaoyao Li (9): x86/split_lock: Rework the initialization flow of split lock detection x86/split_lock: Avoid runtime reads of the TEST_CTRL MSR x86/split_lock: Re-define the kernel param option for split_lock_detect x86/split_lock: Export handle_user_split_lock() kvm: x86: Emulate split-lock access as a write kvm: vmx: Extend VMX's #AC interceptor to handle split lock #AC happens in guest kvm: x86: Emulate MSR IA32_CORE_CAPABILITIES kvm: vmx: Enable MSR_TEST_CTRL for intel guest x86: vmx: virtualize split lock detection .../admin-guide/kernel-parameters.txt | 5 +- arch/x86/include/asm/cpu.h | 23 +++- arch/x86/include/asm/kvm_host.h | 1 + arch/x86/kernel/cpu/intel.c | 119 +++++++++++++----- arch/x86/kernel/traps.c | 2 +- arch/x86/kvm/cpuid.c | 7 +- arch/x86/kvm/vmx/vmx.c | 75 ++++++++++- arch/x86/kvm/vmx/vmx.h | 1 + arch/x86/kvm/x86.c | 42 ++++++- 9 files changed, 229 insertions(+), 46 deletions(-) -- 2.20.1
