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. --- v3 ... v4: 1. Merge LBT feature detection for VM and VCPU into one patch. 2. Move function declaration such as kvm_lose_lbt()/kvm_check_fcsr()/ kvm_enable_lbt_fpu() from header file to c file, since it is only used in one c file. 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 (3): LoongArch: KVM: Add HW Binary Translation extension support LoongArch: KVM: Add LBT feature detection function LoongArch: KVM: Add vm migration support for LBT registers 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: 55027e689933ba2e64f3d245fb1ff185b3e7fc81 -- 2.39.3
