Reviewed-by: Bibo, Mao <maobibo@xxxxxxxxxxx>
在 2023/5/30 09:52, Tianrui Zhao 写道:
> Implement kvm handle gspr exception interface, including emulate the
> reading and writing of cpucfg, csr, iocsr resource.
>
> Signed-off-by: Tianrui Zhao <zhaotianrui@xxxxxxxxxxx>
> ---
> arch/loongarch/kvm/exit.c | 115 ++++++++++++++++++++++++++++++++++++++
> 1 file changed, 115 insertions(+)
>
> diff --git a/arch/loongarch/kvm/exit.c b/arch/loongarch/kvm/exit.c
> index 3fdb42939a05..26283a9d3c6d 100644
> --- a/arch/loongarch/kvm/exit.c
> +++ b/arch/loongarch/kvm/exit.c
> @@ -208,3 +208,118 @@ int _kvm_emu_idle(struct kvm_vcpu *vcpu)
>
> return EMULATE_DONE;
> }
> +
> +static int _kvm_trap_handle_gspr(struct kvm_vcpu *vcpu)
> +{
> + enum emulation_result er = EMULATE_DONE;
> + struct kvm_run *run = vcpu->run;
> + larch_inst inst;
> + unsigned long curr_pc;
> + int rd, rj;
> + unsigned int index;
> +
> + /*
> + * Fetch the instruction.
> + */
> + inst.word = vcpu->arch.badi;
> + curr_pc = vcpu->arch.pc;
> + update_pc(&vcpu->arch);
> +
> + trace_kvm_exit_gspr(vcpu, inst.word);
> + er = EMULATE_FAIL;
> + switch (((inst.word >> 24) & 0xff)) {
> + case 0x0:
> + /* cpucfg GSPR */
> + if (inst.reg2_format.opcode == 0x1B) {
> + rd = inst.reg2_format.rd;
> + rj = inst.reg2_format.rj;
> + ++vcpu->stat.cpucfg_exits;
> + index = vcpu->arch.gprs[rj];
> +
> + vcpu->arch.gprs[rd] = read_cpucfg(index);
> + /* Nested KVM is not supported */
> + if (index == 2)
> + vcpu->arch.gprs[rd] &= ~CPUCFG2_LVZP;
> + if (index == 6)
> + vcpu->arch.gprs[rd] &= ~CPUCFG6_PMP;
> + er = EMULATE_DONE;
> + }
> + break;
> + case 0x4:
> + /* csr GSPR */
> + er = _kvm_handle_csr(vcpu, inst);
> + break;
> + case 0x6:
> + /* iocsr,cache,idle GSPR */
> + switch (((inst.word >> 22) & 0x3ff)) {
> + case 0x18:
> + /* cache GSPR */
> + er = EMULATE_DONE;
> + trace_kvm_exit_cache(vcpu, KVM_TRACE_EXIT_CACHE);
> + break;
> + case 0x19:
> + /* iocsr/idle GSPR */
> + switch (((inst.word >> 15) & 0x1ffff)) {
> + case 0xc90:
> + /* iocsr GSPR */
> + er = _kvm_emu_iocsr(inst, run, vcpu);
> + break;
> + case 0xc91:
> + /* idle GSPR */
> + er = _kvm_emu_idle(vcpu);
> + break;
> + default:
> + er = EMULATE_FAIL;
> + break;
> + }
> + break;
> + default:
> + er = EMULATE_FAIL;
> + break;
> + }
> + break;
> + default:
> + er = EMULATE_FAIL;
> + break;
> + }
> +
> + /* Rollback PC only if emulation was unsuccessful */
> + if (er == EMULATE_FAIL) {
> + kvm_err("[%#lx]%s: unsupported gspr instruction 0x%08x\n",
> + curr_pc, __func__, inst.word);
> +
> + kvm_arch_vcpu_dump_regs(vcpu);
> + vcpu->arch.pc = curr_pc;
> + }
> + return er;
> +}
> +
> +/*
> + * Execute cpucfg instruction will tirggerGSPR,
> + * Also the access to unimplemented csrs 0x15
> + * 0x16, 0x50~0x53, 0x80, 0x81, 0x90~0x95, 0x98
> + * 0xc0~0xff, 0x100~0x109, 0x500~0x502,
> + * cache_op, idle_op iocsr ops the same
> + */
> +static int _kvm_handle_gspr(struct kvm_vcpu *vcpu)
> +{
> + enum emulation_result er = EMULATE_DONE;
> + int ret = RESUME_GUEST;
> +
> + er = _kvm_trap_handle_gspr(vcpu);
> +
> + if (er == EMULATE_DONE) {
> + ret = RESUME_GUEST;
> + } else if (er == EMULATE_DO_MMIO) {
> + vcpu->run->exit_reason = KVM_EXIT_MMIO;
> + ret = RESUME_HOST;
> + } else if (er == EMULATE_DO_IOCSR) {
> + vcpu->run->exit_reason = KVM_EXIT_LOONGARCH_IOCSR;
> + ret = RESUME_HOST;
> + } else {
> + kvm_err("%s internal error\n", __func__);
> + vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
> + ret = RESUME_HOST;
> + }
> + return ret;
> +}
