Hi, Bibo, I have consulted with Jiaxun offline, and he has tried his best to propose a "scratch vcpu" solution. But unfortunately that solution is too difficult to implement and he has nearly given up. So the solution in this series seems the best one, and I will queue it for loongarch-kvm now. Huacai On Tue, Jul 30, 2024 at 3:57 PM Bibo Mao <maobibo@xxxxxxxxxxx> wrote: > > 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 lately enabling method is used for LBT. LBT > context is saved/restored during vcpu context switch path. > > Also this patch set LBT capability detection, and LBT register get and set > interface for userspace vmm, so that vm supports migration with BT > extension. > > --- > v5 ... v6: > 1. Solve compiling issue with function kvm_get_one_reg() and > kvm_set_one_reg(). > > v4 ... v5: > 1. Add feature detection for LSX/LASX from vm side, previously > LSX/LASX feature is detected from vcpu ioctl command, now both > methods are supported. > > 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 | 6 ++ > arch/loongarch/include/uapi/asm/kvm.h | 17 ++++ > arch/loongarch/kvm/exit.c | 9 ++ > arch/loongarch/kvm/vcpu.c | 128 +++++++++++++++++++++++++- > arch/loongarch/kvm/vm.c | 52 ++++++++++- > 6 files changed, 218 insertions(+), 2 deletions(-) > > > base-commit: 8400291e289ee6b2bf9779ff1c83a291501f017b > -- > 2.39.3 > >
