Loongson Binary Translation (LBT) is used to accelerate binary translation, which contains 4 scratch registers (scr0 to scr3), x86/ARM eflags (eflags) and x87 fpu stack pointer (ftop). Like FPU extension, here late enabling method is used for LBT. LBT context is saved/restored on vcpu context switch path. Also this patch set BT capability detection, and BT register get/set interface for userspace vmm, so that vm supports migration with BT extension. --- v2 ... v3: 1. Split KVM_LOONGARCH_VM_FEAT_LBT capability checking into three sub-features, KVM_LOONGARCH_VM_FEAT_X86BT/KVM_LOONGARCH_VM_FEAT_ARMBT and KVM_LOONGARCH_VM_FEAT_MIPSBT. Return success only if host supports the sub-feature. v1 ... v2: 1. With LBT register read or write interface to userpace, replace device attr method with KVM_GET_ONE_REG method, since lbt register is vcpu register and can be added in kvm_reg_list in future. 2. Add vm device attr ctrl marcro KVM_LOONGARCH_VM_FEAT_CTRL, it is used to get supported LBT feature before vm or vcpu is created. --- Bibo Mao (4): LoongArch: KVM: Add HW Binary Translation extension support LoongArch: KVM: Add LBT feature detection with cpucfg LoongArch: KVM: Add vm migration support for LBT registers LoongArch: KVM: Add VM LBT feature detection support arch/loongarch/include/asm/kvm_host.h | 8 ++ arch/loongarch/include/asm/kvm_vcpu.h | 10 +++ arch/loongarch/include/uapi/asm/kvm.h | 15 ++++ arch/loongarch/kvm/exit.c | 9 ++ arch/loongarch/kvm/vcpu.c | 121 +++++++++++++++++++++++++- arch/loongarch/kvm/vm.c | 44 +++++++++- 6 files changed, 205 insertions(+), 2 deletions(-) base-commit: 29c73fc794c83505066ee6db893b2a83ac5fac63 -- 2.39.3
