Linear-address masking (LAM) [1], modifies the checking that is applied to *64-bit* linear addresses, allowing software to use of the untranslated address bits for metadata and masks the metadata bits before using them as linear addresses to access memory. When the feature is virtualized and exposed to guest, it can be used for efficient address sanitizers (ASAN) implementation and for optimizations in JITs and virtual machines. The KVM patch series can be found in [2]. [1] Intel ISE https://cdrdv2.intel.com/v1/dl/getContent/671368 Chapter Linear Address Masking (LAM) [2] https://lore.kernel.org/kvm/20230913124227.12574-1-binbin.wu@xxxxxxxxxxxxxxx --- Changelog v4: - Add a reviewed-by from Xiaoyao for patch 1. - Mask out LAM bit on CR4 if vcpu doesn't support LAM in cpu_x86_update_cr4() (Xiaoyao) v3: - https://lists.gnu.org/archive/html/qemu-devel/2023-07/msg04160.html Binbin Wu (1): target/i386: add control bits support for LAM Robert Hoo (1): target/i386: add support for LAM in CPUID enumeration target/i386/cpu.c | 2 +- target/i386/cpu.h | 9 ++++++++- target/i386/helper.c | 4 ++++ 3 files changed, 13 insertions(+), 2 deletions(-) base-commit: f614acb7450282a119d85d759f27eae190476058 -- 2.25.1
