Commit 13c82f5e authored by Tianrui Zhao's avatar Tianrui Zhao Committed by Huacai Chen
Browse files

LoongArch: KVM: Implement handle gspr exception 



Implement kvm handle gspr exception interface, including emulate the
reading and writing of cpucfg, csr, iocsr resource.

Reviewed-by: default avatarBibo Mao <maobibo@loongson.cn>
Tested-by: default avatarHuacai Chen <chenhuacai@loongson.cn>
Signed-off-by: default avatarTianrui Zhao <zhaotianrui@loongson.cn>
Signed-off-by: default avatarHuacai Chen <chenhuacai@loongson.cn>
parent f41c8bdb

arch/loongarch/kvm/exit.c

+107 −0
Original line number Diff line number Diff line
@@ -214,3 +214,110 @@ int kvm_emu_idle(struct kvm_vcpu *vcpu) 


	return EMULATE_DONE;

}



static int kvm_trap_handle_gspr(struct kvm_vcpu *vcpu)

{

	int rd, rj;

	unsigned int index;

	unsigned long curr_pc;

	larch_inst inst;

	enum emulation_result er = EMULATE_DONE;

	struct kvm_run *run = vcpu->run;



	/* 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];

			er = EMULATE_DONE;

			/*

			 * By LoongArch Reference Manual 2.2.10.5

			 * return value is 0 for undefined cpucfg index

			 */

			if (index < KVM_MAX_CPUCFG_REGS)

				vcpu->arch.gprs[rd] = vcpu->arch.cpucfg[index];

			else

				vcpu->arch.gprs[rd] = 0;

		}

		break;

	case 0x4: /* CSR{RD,WR,XCHG} GSPR */

		er = kvm_handle_csr(vcpu, inst);

		break;

	case 0x6: /* Cache, Idle and IOCSR 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: /* Idle/IOCSR 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;

}



/*

 * Trigger GSPR:

 * 1) Execute CPUCFG instruction;

 * 2) Execute CACOP/IDLE instructions;

 * 3) Access to unimplemented CSRs/IOCSRs.

 */

static int kvm_handle_gspr(struct kvm_vcpu *vcpu)

{

	int ret = RESUME_GUEST;

	enum emulation_result er = EMULATE_DONE;



	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_queue_exception(vcpu, EXCCODE_INE, 0);

		ret = RESUME_GUEST;

	}



	return ret;

}