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: Bibo Mao <maobibo@loongson.cn>
Tested-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Tianrui Zhao <zhaotianrui@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
This commit is contained in:
Tianrui Zhao 2023-10-02 10:01:28 +08:00 committed by Huacai Chen
parent f41c8bdbbd
commit 13c82f5e6e

View file

@ -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;
}